 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| C8051F340/1/2/3/4/5/6/7 Full Speed USB Flash MCU Family Analog Peripherals - 10-Bit ADC * * * * * HIgh Speed 8051 C Core - Pipelined instruction architecture; executes 70% of Instructions in 1 or 2 system clocks Up to 200 ksps Built-in analog multiplexer with single-ended and differential mode VREF from external pin, internal reference, or VDD Built-in temperature sensor External conversion start input option - Two comparators - Internal voltage reference - Brown-out detector and POR Circuitry USB Function Controller - USB specification 2.0 compliant - Full speed (12 Mbps) or low speed (1.5 Mbps) operation - Integrated clock recovery; no external crystal required for On-Chip Debug - On-chip debug circuitry facilitates full speed, non-intrusive in-system debug (No emulator required) Provides breakpoints, single stepping, inspect/modify memory and registers Superior performance to emulation systems using ICE-chips, target pods, and sockets full speed or low speed Supports eight flexible endpoints 1 kB USB buffer memory Integrated transceiver; no external resistors required - 48 MIPS and 25 MIPS versions available. - Expanded interrupt handler Memory - 4352 or 2304 Bytes RAM - 64 or 32 kB Flash; In-system programmable in 512-byte sectors Digital Peripherals - 40/25 Port I/O; All 5 V tolerant with high sink current - Hardware enhanced SPITM, SMBusTM, and one or two enhanced UART serial ports Four general purpose 16-bit counter/timers 16-bit programmable counter array (PCA) with five capture/compare modules External Memory Interface (EMIF) Clock Sources - Internal Oscillator: 0.25% accuracy with clock recovery enabled. Supports all USB and UART modes External Oscillator: Crystal, RC, C, or clock (1 or 2 Pin modes) Low Frequency (80 kHz) Internal Oscillator Can switch between clock sources on-the-fly Voltage Supply Input: 2.7 to 5.25 V - Voltages from 3.6 to 5.25 V supported using On-Chip Voltage Regulator Packages - 48-pin TQFP (C8051F340/1/4/5) - 32-pin LQFP (C8051F342/3/6/7) Temperature Range: -40 to +85 C ANALOG PERIPHERALS A M U X DIGITAL I/O CROSSBAR UART0 UART1 SPI SMBus PCA 4 Timers Port 0 Ext. Memory I/F Port 1 Port 2 Port 3 Port 4 10-bit 200 ksps ADC + + - TEMP SENSOR VREF VREG 48 Pin Only PRECISION INTERNAL OSCILLATORS USB Controller / Transceiver HIGH-SPEED CONTROLLER CORE 64/32 kB ISP FLASH FLEXIBLE INTERRUPTS 8051 CPU (48/25 MIPS) DEBUG CIRCUITRY 4/2 kB RAM POR WDT Rev. 0.5 1/06 Copyright (c) 2006 by Silicon Laboratories C8051F34x This information applies to a product under development. Its characteristics and specifications are subject to change without notice. C8051F340/1/2/3/4/5/6/7 NOTES: 2 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table Of Contents 1. System Overview.................................................................................................... 17 1.1. CIP-51TM Microcontroller Core.......................................................................... 21 1.1.1. Fully 8051 Compatible.............................................................................. 21 1.1.2. Improved Throughput ............................................................................... 21 1.1.3. Additional Features .................................................................................. 21 1.2. On-Chip Memory............................................................................................... 23 1.3. Universal Serial Bus Controller ......................................................................... 24 1.4. Voltage Regulator ............................................................................................. 25 1.5. On-Chip Debug Circuitry................................................................................... 25 1.6. Programmable Digital I/O and Crossbar ........................................................... 26 1.7. Serial Ports ....................................................................................................... 27 1.8. Programmable Counter Array ........................................................................... 27 1.9. 10-Bit Analog to Digital Converter..................................................................... 28 1.10.Comparators..................................................................................................... 29 2. Absolute Maximum Ratings .................................................................................. 30 3. Global DC Electrical Characteristics .................................................................... 31 4. Pinout and Package Definitions............................................................................ 33 5. 10-Bit ADC (ADC0).................................................................................................. 41 5.1. Analog Multiplexer ............................................................................................ 42 5.2. Temperature Sensor ......................................................................................... 43 5.3. Modes of Operation .......................................................................................... 45 5.3.1. Starting a Conversion............................................................................... 45 5.3.2. Tracking Modes........................................................................................ 46 5.3.3. Settling Time Requirements ..................................................................... 47 5.4. Programmable Window Detector ...................................................................... 52 5.4.1. Window Detector In Single-Ended Mode ................................................. 54 5.4.2. Window Detector In Differential Mode...................................................... 55 6. Voltage Reference .................................................................................................. 57 7. Comparators ........................................................................................................... 59 8. Voltage Regulator (REG0)...................................................................................... 69 8.1. Regulator Mode Selection................................................................................. 69 8.2. VBUS Detection ................................................................................................ 69 9. CIP-51 Microcontroller ........................................................................................... 73 9.1. Instruction Set ................................................................................................... 74 9.1.1. Instruction and CPU Timing ..................................................................... 74 9.1.2. MOVX Instruction and Program Memory ................................................. 75 9.2. Memory Organization........................................................................................ 79 9.2.1. Program Memory...................................................................................... 79 9.2.2. Data Memory............................................................................................ 80 9.2.3. General Purpose Registers ...................................................................... 80 9.2.4. Bit Addressable Locations........................................................................ 80 9.2.5. Stack ....................................................................................................... 80 9.2.6. Special Function Registers....................................................................... 81 9.2.7. Register Descriptions ............................................................................... 85 Rev. 0.5 3 C8051F340/1/2/3/4/5/6/7 9.3. Interrupt Handler ............................................................................................... 87 9.3.1. MCU Interrupt Sources and Vectors ........................................................ 87 9.3.2. External Interrupts .................................................................................... 87 9.3.3. Interrupt Priorities ..................................................................................... 88 9.3.4. Interrupt Latency ...................................................................................... 88 9.3.5. Interrupt Register Descriptions................................................................. 89 9.4. Power Management Modes .............................................................................. 96 9.4.1. Idle Mode.................................................................................................. 96 9.4.2. Stop Mode ................................................................................................ 96 10. Prefetch Engine ...................................................................................................... 99 11. Reset Sources....................................................................................................... 101 11.1.Power-On Reset ............................................................................................. 102 11.2.Power-Fail Reset / VDD Monitor .................................................................... 103 11.3.External Reset ................................................................................................ 104 11.4.Missing Clock Detector Reset ........................................................................ 104 11.5.Comparator0 Reset ........................................................................................ 104 11.6.PCA Watchdog Timer Reset .......................................................................... 104 11.7.Flash Error Reset ........................................................................................... 104 11.8.Software Reset ............................................................................................... 105 11.9.USB Reset...................................................................................................... 105 12. Flash Memory ....................................................................................................... 109 12.1.Programming The Flash Memory ................................................................... 109 12.1.1.Flash Lock and Key Functions ............................................................... 109 12.1.2.Flash Erase Procedure .......................................................................... 109 12.1.3.Flash Write Procedure ........................................................................... 110 12.2.Non-volatile Data Storage .............................................................................. 111 12.3.Security Options ............................................................................................. 111 13. External Data Memory Interface and On-Chip XRAM........................................ 117 13.1.Accessing XRAM............................................................................................ 117 13.1.1.16-Bit MOVX Example ........................................................................... 117 13.1.2.8-Bit MOVX Example ............................................................................. 117 13.2.Accessing USB FIFO Space .......................................................................... 118 13.3.Configuring the External Memory Interface .................................................... 119 13.4.Port Configuration........................................................................................... 119 13.5.Multiplexed and Non-multiplexed Selection.................................................... 122 13.5.1.Multiplexed Configuration....................................................................... 122 13.5.2.Non-multiplexed Configuration............................................................... 123 13.6.Memory Mode Selection................................................................................. 123 13.6.1.Internal XRAM Only ............................................................................... 124 13.6.2.Split Mode without Bank Select.............................................................. 124 13.6.3.Split Mode with Bank Select................................................................... 125 13.6.4.External Only.......................................................................................... 125 13.7.Timing .......................................................................................................... 125 13.7.1.Non-multiplexed Mode ........................................................................... 127 13.7.2.Multiplexed Mode ................................................................................... 130 4 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 14. Oscillators ............................................................................................................. 135 14.1.Programmable Internal High-Frequency (H-F) Oscillator ............................... 136 14.1.1.Internal H-F Oscillator Suspend Mode ................................................... 136 14.2.Programmable Internal Low-Frequency (L-F) Oscillator ................................ 137 14.2.1.Calibrating the Internal L-F Oscillator..................................................... 137 14.3.External Oscillator Drive Circuit...................................................................... 139 14.3.1.Clocking Timers Directly Through the External Oscillator...................... 139 14.3.2.External Crystal Example....................................................................... 139 14.3.3.External RC Example............................................................................. 140 14.3.4.External Capacitor Example................................................................... 140 14.4.4x Clock Multiplier .......................................................................................... 142 14.5.System and USB Clock Selection .................................................................. 143 14.5.1.System Clock Selection ......................................................................... 143 14.5.2.USB Clock Selection .............................................................................. 143 15. Port Input/Output.................................................................................................. 147 15.1.Priority Crossbar Decoder .............................................................................. 149 15.2.Port I/O Initialization ....................................................................................... 151 15.3.General Purpose Port I/O ............................................................................... 154 16. Universal Serial Bus Controller (USB0).............................................................. 163 16.1.Endpoint Addressing ...................................................................................... 164 16.2.USB Transceiver ............................................................................................ 164 16.3.USB Register Access ..................................................................................... 166 16.4.USB Clock Configuration................................................................................ 170 16.5.FIFO Management ......................................................................................... 171 16.5.1.FIFO Split Mode ..................................................................................... 171 16.5.2.FIFO Double Buffering ........................................................................... 172 16.5.3.FIFO Access .......................................................................................... 172 16.6.Function Addressing....................................................................................... 173 16.7.Function Configuration and Control................................................................ 173 16.8.Interrupts ........................................................................................................ 176 16.9.The Serial Interface Engine ............................................................................ 180 16.10.Endpoint0 ..................................................................................................... 180 16.10.1.Endpoint0 SETUP Transactions .......................................................... 181 16.10.2.Endpoint0 IN Transactions................................................................... 181 16.10.3.Endpoint0 OUT Transactions............................................................... 182 16.11.Configuring Endpoints1-3 ............................................................................. 184 16.12.Controlling Endpoints1-3 IN.......................................................................... 184 16.12.1.Endpoints1-3 IN Interrupt or Bulk Mode............................................... 184 16.12.2.Endpoints1-3 IN Isochronous Mode..................................................... 185 16.13.Controlling Endpoints1-3 OUT...................................................................... 187 16.13.1.Endpoints1-3 OUT Interrupt or Bulk Mode........................................... 187 16.13.2.Endpoints1-3 OUT Isochronous Mode................................................. 188 17. SMBus ................................................................................................................... 193 17.1.Supporting Documents ................................................................................... 194 17.2.SMBus Configuration...................................................................................... 194 Rev. 0.5 5 C8051F340/1/2/3/4/5/6/7 17.3.SMBus Operation ........................................................................................... 194 17.3.1.Arbitration............................................................................................... 195 17.3.2.Clock Low Extension.............................................................................. 196 17.3.3.SCL Low Timeout................................................................................... 196 17.3.4.SCL High (SMBus Free) Timeout .......................................................... 196 17.4.Using the SMBus............................................................................................ 196 17.4.1.SMBus Configuration Register............................................................... 198 17.4.2.SMB0CN Control Register ..................................................................... 201 17.4.3.Data Register ......................................................................................... 204 17.5.SMBus Transfer Modes.................................................................................. 204 17.5.1.Master Transmitter Mode ....................................................................... 204 17.5.2.Master Receiver Mode ........................................................................... 206 17.5.3.Slave Receiver Mode ............................................................................. 207 17.5.4.Slave Transmitter Mode ......................................................................... 208 17.6.SMBus Status Decoding................................................................................. 208 18. UART0.................................................................................................................... 211 18.1.Enhanced Baud Rate Generation................................................................... 212 18.2.Operational Modes ......................................................................................... 212 18.2.1.8-Bit UART ............................................................................................. 213 18.2.2.9-Bit UART ............................................................................................. 214 18.3.Multiprocessor Communications .................................................................... 214 19. UART1 (C8051F340/1/4/5 Only) ........................................................................... 219 19.1.Baud Rate Generator ..................................................................................... 220 19.2.Data Format.................................................................................................... 221 19.3.Configuration and Operation .......................................................................... 222 19.3.1.Data Transmission ................................................................................. 222 19.3.2.Data Reception ...................................................................................... 222 19.3.3.Multiprocessor Communications ............................................................ 223 20. Enhanced Serial Peripheral Interface (SPI0)...................................................... 229 20.1.Signal Descriptions......................................................................................... 230 20.1.1.Master Out, Slave In (MOSI).................................................................. 230 20.1.2.Master In, Slave Out (MISO).................................................................. 230 20.1.3.Serial Clock (SCK) ................................................................................. 230 20.1.4.Slave Select (NSS) ................................................................................ 230 20.2.SPI0 Master Mode Operation ......................................................................... 231 20.3.SPI0 Slave Mode Operation ........................................................................... 233 20.4.SPI0 Interrupt Sources ................................................................................... 233 20.5.Serial Clock Timing......................................................................................... 234 20.6.SPI Special Function Registers ...................................................................... 236 21. Timers.................................................................................................................... 243 21.1.Timer 0 and Timer 1 ....................................................................................... 243 21.1.1.Mode 0: 13-bit Counter/Timer ................................................................ 243 21.1.2.Mode 1: 16-bit Counter/Timer ................................................................ 244 21.1.3.Mode 2: 8-bit Counter/Timer with Auto-Reload...................................... 245 21.1.4.Mode 3: Two 8-bit Counter/Timers (Timer 0 Only)................................. 246 6 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 21.2.Timer 2 .......................................................................................................... 251 21.2.1.16-bit Timer with Auto-Reload................................................................ 251 21.2.2.8-bit Timers with Auto-Reload................................................................ 252 21.2.3.Timer 2 Capture Modes: USB Start-of-Frame or LFO Falling Edge ...... 253 21.3.Timer 3 .......................................................................................................... 257 21.3.1.16-bit Timer with Auto-Reload................................................................ 257 21.3.2.8-bit Timers with Auto-Reload................................................................ 258 21.3.3.USB Start-of-Frame Capture.................................................................. 259 22. Programmable Counter Array (PCA0) ................................................................ 263 22.1.PCA Counter/Timer ........................................................................................ 264 22.2.Capture/Compare Modules ............................................................................ 265 22.2.1.Edge-triggered Capture Mode................................................................ 266 22.2.2.Software Timer (Compare) Mode........................................................... 267 22.2.3.High Speed Output Mode....................................................................... 268 22.2.4.Frequency Output Mode ........................................................................ 269 22.2.5.8-Bit Pulse Width Modulator Mode......................................................... 270 22.2.6.16-Bit Pulse Width Modulator Mode....................................................... 271 22.3.Watchdog Timer Mode ................................................................................... 272 22.3.1.Watchdog Timer Operation .................................................................... 272 22.3.2.Watchdog Timer Usage ......................................................................... 273 22.4.Register Descriptions for PCA........................................................................ 274 23. C2 Interface ........................................................................................................... 279 23.1.C2 Interface Registers.................................................................................... 279 23.2.C2 Pin Sharing ............................................................................................... 281 Contact Information.................................................................................................. 282 Rev. 0.5 7 C8051F340/1/2/3/4/5/6/7 NOTES: 8 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 List of Figures and Tables 1. System Overview Table 1.1. Product Selection Guide ........................................................................ 18 Figure 1.1. C8051F340/1/4/5 Block Diagram ........................................................... 19 Figure 1.2. C8051F342/3/6/7 Block Diagram ........................................................... 20 Figure 1.3. On-Chip Clock and Reset ...................................................................... 22 Figure 1.4. On-Chip Memory Map for 64kB Devices (C8051F340/2/4/6) ................ 23 Figure 1.5. USB Controller Block Diagram............................................................... 24 Figure 1.6. Digital Crossbar Diagram ....................................................................... 26 Figure 1.7. PCA Block Diagram ............................................................................... 27 Figure 1.8. PCA Block Diagram ............................................................................... 27 Figure 1.9. 10-Bit ADC Block Diagram..................................................................... 28 Figure 1.10. Comparator0 Block Diagram ................................................................ 29 2. Absolute Maximum Ratings Table 2.1. Absolute Maximum Ratings ................................................................... 30 3. Global DC Electrical Characteristics Table 3.1. Global DC Electrical Characteristics ...................................................... 31 Table 3.2. Index to Electrical Characteristics Tables .............................................. 32 4. Pinout and Package Definitions Table 4.1. Pin Definitions for the C8051F340/1/2/3/4/5/6/7 .................................... 33 Figure 4.1. TQFP-48 Pinout Diagram (Top View) .................................................... 36 Table 4.2. TQFP-48 Package Dimensions.............................................................. 37 Figure 4.2. TQFP-48 Package Diagram................................................................... 37 Figure 4.3. LQFP-32 Pinout Diagram (Top View) .................................................... 38 Table 4.3. LQFP-32 Package Dimensions.............................................................. 39 Figure 4.4. LQFP-32 Package Diagram ................................................................... 39 5. 10-Bit ADC (ADC0) Figure 5.1. ADC0 Functional Block Diagram............................................................ 41 Figure 5.2. Temperature Sensor Transfer Function ................................................. 43 Figure 5.3. Temperature Sensor Error with 1-Point Calibration (VREF = 2.40 V).... 44 Figure 5.4. 10-Bit ADC Track and Conversion Example Timing .............................. 46 Figure 5.5. ADC0 Equivalent Input Circuits.............................................................. 47 Figure 5.6. ADC Window Compare Example: Right-Justified Single-Ended Data ... 54 Figure 5.7. ADC Window Compare Example: Left-Justified Single-Ended Data ..... 54 Figure 5.8. ADC Window Compare Example: Right-Justified Differential Data ....... 55 Figure 5.9. ADC Window Compare Example: Left-Justified Differential Data.......... 55 Table 5.1. ADC0 Electrical Characteristics ............................................................. 56 6. Voltage Reference Figure 6.1. Voltage Reference Functional Block Diagram ....................................... 57 Table 6.1. Voltage Reference Electrical Characteristics ......................................... 58 7. Comparators Figure 7.1. Comparator Functional Block Diagram .................................................. 60 Figure 7.2. Comparator Hysteresis Plot ................................................................... 61 Table 7.1. Comparator Electrical Characteristics.................................................... 68 Rev. 0.5 9 C8051F340/1/2/3/4/5/6/7 8. Voltage Regulator (REG0) Table 8.1. Voltage Regulator Electrical Specifications............................................ 69 Figure 8.1. REG0 Configuration: USB Bus-Powered ............................................... 70 Figure 8.2. REG0 Configuration: USB Self-Powered ............................................... 70 Figure 8.3. REG0 Configuration: USB Self-Powered, Regulator Disabled .............. 71 Figure 8.4. REG0 Configuration: No USB Connection............................................. 71 9. CIP-51 Microcontroller Figure 9.1. CIP-51 Block Diagram............................................................................ 73 Table 9.1. CIP-51 Instruction Set Summary............................................................ 75 Figure 9.2. Memory Map .......................................................................................... 79 Table 9.2. Special Function Register (SFR) Memory Map...................................... 81 Table 9.3. Special Function Registers .................................................................... 82 Table 9.4. Interrupt Summary ................................................................................. 89 10. Prefetch Engine 11. Reset Sources Figure 11.1. Reset Sources.................................................................................... 101 Figure 11.2. Power-On and VDD Monitor Reset Timing ........................................ 102 Table 11.1. Reset Electrical Characteristics........................................................... 107 12. Flash Memory Table 12.1. Flash Electrical Characteristics ........................................................... 111 Figure 12.1. Flash Program Memory Map and Security Byte................................. 112 13. External Data Memory Interface and On-Chip XRAM Figure 13.1. USB FIFO Space and XRAM Memory Map with USBFAE set to `1' .. 118 Figure 13.2. Multiplexed Configuration Example.................................................... 122 Figure 13.3. Non-multiplexed Configuration Example ............................................ 123 Figure 13.4. EMIF Operating Modes ...................................................................... 123 Figure 13.5. Non-multiplexed 16-bit MOVX Timing ................................................ 127 Figure 13.6. Non-multiplexed 8-bit MOVX without Bank Select Timing ................. 128 Figure 13.7. Non-multiplexed 8-bit MOVX with Bank Select Timing ...................... 129 Figure 13.8. Multiplexed 16-bit MOVX Timing........................................................ 130 Figure 13.9. Multiplexed 8-bit MOVX without Bank Select Timing ......................... 131 Figure 13.10. Multiplexed 8-bit MOVX with Bank Select Timing ............................ 132 Table 13.1. AC Parameters for External Memory Interface.................................... 133 14. Oscillators Figure 14.1. Oscillator Diagram.............................................................................. 135 Table 14.1. Oscillator Electrical Characteristics ..................................................... 145 15. Port Input/Output Figure 15.1. Port I/O Functional Block Diagram (Port 0 through Port 3) ................ 147 Figure 15.2. Port I/O Cell Block Diagram ............................................................... 148 Figure 15.3. Crossbar Priority Decoder with No Pins Skipped ............................... 149 Figure 15.4. Crossbar Priority Decoder with Crystal Pins Skipped ........................ 150 Table 15.1. Port I/O DC Electrical Characteristics.................................................. 162 16. Universal Serial Bus Controller (USB0) Figure 16.1. USB0 Block Diagram.......................................................................... 163 Table 16.1. Endpoint Addressing Scheme ............................................................. 164 10 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Figure 16.2. USB0 Register Access Scheme......................................................... 166 Table 16.2. USB0 Controller Registers .................................................................. 169 Figure 16.3. USB FIFO Allocation .......................................................................... 171 Table 16.3. FIFO Configurations ............................................................................ 172 Table 16.4. USB Transceiver Electrical Characteristics ......................................... 191 17. SMBus Figure 17.1. SMBus Block Diagram ....................................................................... 193 Figure 17.2. Typical SMBus Configuration ............................................................. 194 Figure 17.3. SMBus Transaction ............................................................................ 195 Table 17.1. SMBus Clock Source Selection........................................................... 198 Figure 17.4. Typical SMBus SCL Generation......................................................... 199 Table 17.2. Minimum SDA Setup and Hold Times ................................................. 199 Table 17.3. Sources for Hardware Changes to SMB0CN ...................................... 203 Figure 17.5. Typical Master Transmitter Sequence................................................ 205 Figure 17.6. Typical Master Receiver Sequence.................................................... 206 Figure 17.7. Typical Slave Receiver Sequence...................................................... 207 Figure 17.8. Typical Slave Transmitter Sequence.................................................. 208 Table 17.4. SMBus Status Decoding...................................................................... 209 18. UART0 Figure 18.1. UART0 Block Diagram ....................................................................... 211 Figure 18.2. UART0 Baud Rate Logic .................................................................... 212 Figure 18.3. UART Interconnect Diagram .............................................................. 213 Figure 18.4. 8-Bit UART Timing Diagram............................................................... 213 Figure 18.5. 9-Bit UART Timing Diagram............................................................... 214 Figure 18.6. UART Multi-Processor Mode Interconnect Diagram .......................... 215 Table 18.1. Timer Settings for Standard Baud Rates Using The Internal Oscillator ............................................................... 218 19. UART1 (C8051F340/1/4/5 Only) Figure 19.1. UART1 Block Diagram ....................................................................... 219 Table 19.1. Baud Rate Generator Settings for Standard Baud Rates.................... 220 Figure 19.2. UART1 Timing Without Parity or Extra Bit.......................................... 221 Figure 19.3. UART1 Timing With Parity ................................................................. 221 Figure 19.4. UART1 Timing With Extra Bit ............................................................. 221 Figure 19.5. Typical UART Interconnect Diagram.................................................. 222 Figure 19.6. UART Multi-Processor Mode Interconnect Diagram .......................... 223 20. Enhanced Serial Peripheral Interface (SPI0) Figure 20.1. SPI Block Diagram ............................................................................. 229 Figure 20.2. Multiple-Master Mode Connection Diagram ....................................... 232 Figure 20.3. 3-Wire Single Master and Slave Mode Connection Diagram ............. 232 Figure 20.4. 4-Wire Single Master Mode and Slave Mode Connection Diagram ... 232 Figure 20.5. Master Mode Data/Clock Timing ........................................................ 234 Figure 20.6. Slave Mode Data/Clock Timing (CKPHA = 0) .................................... 235 Figure 20.7. Slave Mode Data/Clock Timing (CKPHA = 1) .................................... 235 Figure 20.8. SPI Master Timing (CKPHA = 0)........................................................ 239 Figure 20.9. SPI Master Timing (CKPHA = 1)........................................................ 239 Rev. 0.5 11 C8051F340/1/2/3/4/5/6/7 Figure 20.10. SPI Slave Timing (CKPHA = 0)........................................................ 240 Figure 20.11. SPI Slave Timing (CKPHA = 1)........................................................ 240 Table 20.1. SPI Slave Timing Parameters ............................................................. 241 21. Timers Figure 21.1. T0 Mode 0 Block Diagram.................................................................. 244 Figure 21.2. T0 Mode 2 Block Diagram.................................................................. 245 Figure 21.3. T0 Mode 3 Block Diagram.................................................................. 246 Figure 21.4. Timer 2 16-Bit Mode Block Diagram .................................................. 251 Figure 21.5. Timer 2 8-Bit Mode Block Diagram .................................................... 252 Figure 21.6. Timer 2 Capture Mode (T2SPLIT = `0') .............................................. 253 Figure 21.7. Timer 2 Capture Mode (T2SPLIT = `1') .............................................. 254 Figure 21.8. Timer 3 16-Bit Mode Block Diagram .................................................. 257 Figure 21.9. Timer 3 8-Bit Mode Block Diagram .................................................... 258 Figure 21.10. Timer 3 Capture Mode (T3SPLIT = `0') ............................................ 259 Figure 21.11. Timer 3 Capture Mode (T3SPLIT = `1') ............................................ 260 22. Programmable Counter Array (PCA0) Figure 22.1. PCA Block Diagram............................................................................ 263 Table 22.1. PCA Timebase Input Options .............................................................. 264 Figure 22.2. PCA Counter/Timer Block Diagram.................................................... 264 Table 22.2. PCA0CPM Register Settings for PCA Capture/Compare Modules ..... 265 Figure 22.3. PCA Interrupt Block Diagram ............................................................. 265 Figure 22.4. PCA Capture Mode Diagram.............................................................. 266 Figure 22.5. PCA Software Timer Mode Diagram .................................................. 267 Figure 22.6. PCA High Speed Output Mode Diagram............................................ 268 Figure 22.7. PCA Frequency Output Mode ............................................................ 269 Figure 22.8. PCA 8-Bit PWM Mode Diagram ......................................................... 270 Figure 22.9. PCA 16-Bit PWM Mode...................................................................... 271 Figure 22.10. PCA Module 4 with Watchdog Timer Enabled ................................. 272 Table 22.3. Watchdog Timer Timeout Intervals1.................................................... 273 23. C2 Interface Figure 23.1. Typical C2 Pin Sharing....................................................................... 281 12 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 List of Registers SFR Definition 5.1. AMX0P: AMUX0 Positive Channel Select . . . . . . . . . . . . . . . . . . . 48 SFR Definition 5.2. AMX0N: AMUX0 Negative Channel Select . . . . . . . . . . . . . . . . . . 49 SFR Definition 5.3. ADC0CF: ADC0 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 SFR Definition 5.4. ADC0H: ADC0 Data Word MSB . . . . . . . . . . . . . . . . . . . . . . . . . . 50 SFR Definition 5.5. ADC0L: ADC0 Data Word LSB . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 SFR Definition 5.6. ADC0CN: ADC0 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 SFR Definition 5.7. ADC0GTH: ADC0 Greater-Than Data High Byte . . . . . . . . . . . . . 52 SFR Definition 5.8. ADC0GTL: ADC0 Greater-Than Data Low Byte . . . . . . . . . . . . . . 52 SFR Definition 5.9. ADC0LTH: ADC0 Less-Than Data High Byte . . . . . . . . . . . . . . . . 53 SFR Definition 5.10. ADC0LTL: ADC0 Less-Than Data Low Byte . . . . . . . . . . . . . . . 53 SFR Definition 6.1. REF0CN: Reference Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 SFR Definition 7.1. CPT0CN: Comparator0 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 SFR Definition 7.2. CPT0MX: Comparator0 MUX Selection . . . . . . . . . . . . . . . . . . . . 63 SFR Definition 7.3. CPT0MD: Comparator0 Mode Selection . . . . . . . . . . . . . . . . . . . . 64 SFR Definition 7.4. CPT1CN: Comparator1 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 SFR Definition 7.5. CPT1MX: Comparator1 MUX Selection . . . . . . . . . . . . . . . . . . . . 66 SFR Definition 7.6. CPT1MD: Comparator1 Mode Selection . . . . . . . . . . . . . . . . . . . . 67 SFR Definition 8.1. REG0CN: Voltage Regulator Control . . . . . . . . . . . . . . . . . . . . . . 72 SFR Definition 9.1. DPL: Data Pointer Low Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 SFR Definition 9.2. DPH: Data Pointer High Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 SFR Definition 9.3. SP: Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 SFR Definition 9.4. PSW: Program Status Word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 SFR Definition 9.5. ACC: Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 SFR Definition 9.6. B: B Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 SFR Definition 9.7. IE: Interrupt Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 SFR Definition 9.8. IP: Interrupt Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 SFR Definition 9.9. EIE1: Extended Interrupt Enable 1 . . . . . . . . . . . . . . . . . . . . . . . . 92 SFR Definition 9.10. EIP1: Extended Interrupt Priority 1 . . . . . . . . . . . . . . . . . . . . . . . 93 SFR Definition 9.11. EIE2: Extended Interrupt Enable 2 . . . . . . . . . . . . . . . . . . . . . . . 94 SFR Definition 9.12. EIP2: Extended Interrupt Priority 2 . . . . . . . . . . . . . . . . . . . . . . . 94 SFR Definition 9.13. IT01CF: INT0/INT1 Configuration . . . . . . . . . . . . . . . . . . . . . . . . 95 SFR Definition 9.14. PCON: Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 SFR Definition 10.1. PFE0CN: Prefetch Engine Control . . . . . . . . . . . . . . . . . . . . . . . 99 SFR Definition 11.1. VDM0CN: VDD Monitor Control . . . . . . . . . . . . . . . . . . . . . . . . . 103 SFR Definition 11.2. RSTSRC: Reset Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 SFR Definition 12.1. PSCTL: Program Store R/W Control . . . . . . . . . . . . . . . . . . . . . 114 SFR Definition 12.2. FLKEY: Flash Lock and Key . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 SFR Definition 12.3. FLSCL: Flash Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 SFR Definition 13.1. EMI0CN: External Memory Interface Control . . . . . . . . . . . . . . 120 SFR Definition 13.2. EMI0CF: External Memory Configuration . . . . . . . . . . . . . . . . . 121 SFR Definition 13.3. EMI0TC: External Memory Timing Control . . . . . . . . . . . . . . . . 126 SFR Definition 14.1. OSCICN: Internal H-F Oscillator Control . . . . . . . . . . . . . . . . . . 136 SFR Definition 14.2. OSCICL: Internal H-F Oscillator Calibration . . . . . . . . . . . . . . . 137 Rev. 0.5 13 C8051F340/1/2/3/4/5/6/7 SFR Definition 14.3. OSCLCN: Internal L-F Oscillator Control . . . . . . . . . . . . . . . . . . 138 SFR Definition 14.4. OSCXCN: External Oscillator Control . . . . . . . . . . . . . . . . . . . . 141 SFR Definition 14.5. CLKMUL: Clock Multiplier Control . . . . . . . . . . . . . . . . . . . . . . . 142 SFR Definition 14.6. CLKSEL: Clock Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 SFR Definition 15.1. XBR0: Port I/O Crossbar Register 0 . . . . . . . . . . . . . . . . . . . . . 152 SFR Definition 15.2. XBR1: Port I/O Crossbar Register 1 . . . . . . . . . . . . . . . . . . . . . 153 SFR Definition 15.3. XBR2: Port I/O Crossbar Register 2 . . . . . . . . . . . . . . . . . . . . . 153 SFR Definition 15.4. P0: Port0 Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 SFR Definition 15.5. P0MDIN: Port0 Input Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 SFR Definition 15.6. P0MDOUT: Port0 Output Mode . . . . . . . . . . . . . . . . . . . . . . . . 155 SFR Definition 15.7. P0SKIP: Port0 Skip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 SFR Definition 15.8. P1: Port1 Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 SFR Definition 15.9. P1MDIN: Port1 Input Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 SFR Definition 15.10. P1MDOUT: Port1 Output Mode . . . . . . . . . . . . . . . . . . . . . . . . 156 SFR Definition 15.11. P1SKIP: Port1 Skip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 SFR Definition 15.12. P2: Port2 Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 SFR Definition 15.13. P2MDIN: Port2 Input Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 SFR Definition 15.14. P2MDOUT: Port2 Output Mode . . . . . . . . . . . . . . . . . . . . . . . . 158 SFR Definition 15.15. P2SKIP: Port2 Skip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 SFR Definition 15.16. P3: Port3 Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 SFR Definition 15.17. P3MDIN: Port3 Input Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 SFR Definition 15.18. P3MDOUT: Port3 Output Mode . . . . . . . . . . . . . . . . . . . . . . . . 159 SFR Definition 15.19. P3SKIP: Port3 Skip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 SFR Definition 15.20. P4: Port4 Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 SFR Definition 15.21. P4MDIN: Port4 Input Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 SFR Definition 15.22. P4MDOUT: Port4 Output Mode . . . . . . . . . . . . . . . . . . . . . . . . 161 SFR Definition 16.1. USB0XCN: USB0 Transceiver Control . . . . . . . . . . . . . . . . . . . 165 SFR Definition 16.2. USB0ADR: USB0 Indirect Address . . . . . . . . . . . . . . . . . . . . . . 167 SFR Definition 16.3. USB0DAT: USB0 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 USB Register Definition 16.4. INDEX: USB0 Endpoint Index . . . . . . . . . . . . . . . . . . . 169 USB Register Definition 16.5. CLKREC: Clock Recovery Control . . . . . . . . . . . . . . . 170 USB Register Definition 16.6. FIFOn: USB0 Endpoint FIFO Access . . . . . . . . . . . . . 172 USB Register Definition 16.7. FADDR: USB0 Function Address . . . . . . . . . . . . . . . . 173 USB Register Definition 16.8. POWER: USB0 Power . . . . . . . . . . . . . . . . . . . . . . . . 175 USB Register Definition 16.9. FRAMEL: USB0 Frame Number Low . . . . . . . . . . . . . 176 USB Register Definition 16.10. FRAMEH: USB0 Frame Number High . . . . . . . . . . . 176 USB Register Definition 16.11. IN1INT: USB0 IN Endpoint Interrupt . . . . . . . . . . . . . 177 USB Register Definition 16.12. OUT1INT: USB0 Out Endpoint Interrupt . . . . . . . . . . 177 USB Register Definition 16.13. CMINT: USB0 Common Interrupt . . . . . . . . . . . . . . . 178 USB Register Definition 16.14. IN1IE: USB0 IN Endpoint Interrupt Enable . . . . . . . . 179 USB Register Definition 16.15. OUT1IE: USB0 Out Endpoint Interrupt Enable . . . . . 179 USB Register Definition 16.16. CMIE: USB0 Common Interrupt Enable . . . . . . . . . . 180 USB Register Definition 16.17. E0CSR: USB0 Endpoint0 Control . . . . . . . . . . . . . . . 183 USB Register Definition 16.18. E0CNT: USB0 Endpoint 0 Data Count . . . . . . . . . . . 184 USB Register Definition 16.19. EINCSRL: USB0 IN Endpoint Control Low Byte . . . . 186 14 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.20. EINCSRH: USB0 IN Endpoint Control High Byte . . . 187 USB Register Definition 16.21. EOUTCSRL: USB0 OUT Endpoint Control Low Byte 189 USB Register Definition 16.22. EOUTCSRH: USB0 OUT Endpoint Control High Byte 190 USB Register Definition 16.23. EOUTCNTL: USB0 OUT Endpoint Count Low . . . . . 190 USB Register Definition 16.24. EOUTCNTH: USB0 OUT Endpoint Count High . . . . 190 SFR Definition 17.1. SMB0CF: SMBus Clock/Configuration . . . . . . . . . . . . . . . . . . . 200 SFR Definition 17.2. SMB0CN: SMBus Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 SFR Definition 17.3. SMB0DAT: SMBus Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 SFR Definition 18.1. SCON0: Serial Port 0 Control . . . . . . . . . . . . . . . . . . . . . . . . . . 216 SFR Definition 18.2. SBUF0: Serial (UART0) Port Data Buffer . . . . . . . . . . . . . . . . . 217 SFR Definition 19.1. SCON1: UART1 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 SFR Definition 19.2. SMOD1: UART1 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 SFR Definition 19.3. SBUF1: UART1 Data Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 SFR Definition 19.4. SBCON1: UART1 Baud Rate Generator Control . . . . . . . . . . . 226 SFR Definition 19.5. SBRLH1: UART1 Baud Rate Generator High Byte . . . . . . . . . . 227 SFR Definition 19.6. SBRLL1: UART1 Baud Rate Generator Low Byte . . . . . . . . . . . 227 SFR Definition 20.1. SPI0CFG: SPI0 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 236 SFR Definition 20.2. SPI0CN: SPI0 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 SFR Definition 20.3. SPI0CKR: SPI0 Clock Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 SFR Definition 20.4. SPI0DAT: SPI0 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 SFR Definition 21.1. TCON: Timer Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 SFR Definition 21.2. TMOD: Timer Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 SFR Definition 21.3. CKCON: Clock Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 SFR Definition 21.4. TL0: Timer 0 Low Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 SFR Definition 21.5. TL1: Timer 1 Low Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 SFR Definition 21.6. TH0: Timer 0 High Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 SFR Definition 21.7. TH1: Timer 1 High Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 SFR Definition 21.8. TMR2CN: Timer 2 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 SFR Definition 21.9. TMR2RLL: Timer 2 Reload Register Low Byte . . . . . . . . . . . . . 256 SFR Definition 21.10. TMR2RLH: Timer 2 Reload Register High Byte . . . . . . . . . . . 256 SFR Definition 21.11. TMR2L: Timer 2 Low Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 SFR Definition 21.12. TMR2H Timer 2 High Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 SFR Definition 21.13. TMR3CN: Timer 3 Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 SFR Definition 21.14. TMR3RLL: Timer 3 Reload Register Low Byte . . . . . . . . . . . . 262 SFR Definition 21.15. TMR3RLH: Timer 3 Reload Register High Byte . . . . . . . . . . . 262 SFR Definition 21.16. TMR3L: Timer 3 Low Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 SFR Definition 21.17. TMR3H Timer 3 High Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 SFR Definition 22.1. PCA0CN: PCA Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 SFR Definition 22.2. PCA0MD: PCA Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 SFR Definition 22.3. PCA0CPMn: PCA Capture/Compare Mode . . . . . . . . . . . . . . . 276 SFR Definition 22.4. PCA0L: PCA Counter/Timer Low Byte . . . . . . . . . . . . . . . . . . . 277 SFR Definition 22.5. PCA0H: PCA Counter/Timer High Byte . . . . . . . . . . . . . . . . . . . 277 SFR Definition 22.6. PCA0CPLn: PCA Capture Module Low Byte . . . . . . . . . . . . . . . 277 SFR Definition 22.7. PCA0CPHn: PCA Capture Module High Byte . . . . . . . . . . . . . . 278 C2 Register Definition 23.1. C2ADD: C2 Address . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Rev. 0.5 15 C8051F340/1/2/3/4/5/6/7 C2 Register Definition 23.2. DEVICEID: C2 Device ID . . . . . . . . . . . . . . . . . . . . . . . . 279 C2 Register Definition 23.3. REVID: C2 Revision ID . . . . . . . . . . . . . . . . . . . . . . . . . 280 C2 Register Definition 23.4. FPCTL: C2 Flash Programming Control . . . . . . . . . . . . 280 C2 Register Definition 23.5. FPDAT: C2 Flash Programming Data . . . . . . . . . . . . . . 280 16 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 1. System Overview C8051F340/1/2/3/4/5/6/7 devices are fully integrated mixed-signal System-on-a-Chip MCUs. Highlighted features are listed below. Refer to Table 1.1 for specific product feature selection. * * * * * * * * * * * * * * * * * High-speed pipelined 8051-compatible microcontroller core (up to 48 MIPS) In-system, full-speed, non-intrusive debug interface (on-chip) Universal Serial Bus (USB) Function Controller with eight flexible endpoint pipes, integrated transceiver, and 1 kB FIFO RAM Supply Voltage Regulator True 10-bit 200 ksps differential / single-ended ADC with analog multiplexer On-chip Voltage Reference and Temperature Sensor On-chip Voltage Comparators (2) Precision internal calibrated 12 MHz internal oscillator and 4x clock multiplier Internal low-frequency oscillator for additional power savings Up to 64 kB of on-chip Flash memory Up to 4352 Bytes of on-chip RAM (256 + 4 kB) External Memory Interface (EMIF) available on 48-pin versions. SMBus/I2C, up to 2 UARTs, and Enhanced SPI serial interfaces implemented in hardware Four general-purpose 16-bit timers Programmable Counter/Timer Array (PCA) with five capture/compare modules and Watchdog Timer function On-chip Power-On Reset, VDD Monitor, and Missing Clock Detector Up to 40 Port I/O (5 V tolerant) With on-chip Power-On Reset, VDD monitor, Voltage Regulator, Watchdog Timer, and clock oscillator, C8051F340/1/2/3/4/5/6/7 devices are truly stand-alone System-on-a-Chip solutions. The Flash memory can be reprogrammed in-circuit, providing non-volatile data storage, and also allowing field upgrades of the 8051 firmware. User software has complete control of all peripherals, and may individually shut down any or all peripherals for power savings. The on-chip Silicon Labs 2-Wire (C2) Development Interface allows non-intrusive (uses no on-chip resources), full speed, in-circuit debugging using the production MCU installed in the final application. This debug logic supports inspection and modification of memory and registers, setting breakpoints, single stepping, run and halt commands. All analog and digital peripherals are fully functional while debugging using C2. The two C2 interface pins can be shared with user functions, allowing in-system debugging without occupying package pins. Each device is specified for 2.7-5.25 V operation over the industrial temperature range (-40 to +85 C). For voltages above 3.6 V, the on-chip Voltage Regulator must be used. A minimum of 3.0 V is required for USB communication. The Port I/O and /RST pins are tolerant of input signals up to 5 V. C8051F340/1/2/3/ 4/5/6/7 are available in a 48-pin TQFP or a 32-pin LQFP package. Rev. 0.5 17 C8051F340/1/2/3/4/5/6/7 Table 1.1. Product Selection Guide External Memory Interface (EMIF) Programmable Counter Array Calibrated Internal Oscillator USB with 1k Endpoint RAM Low Frequency Oscillator Supply Voltage Regulator Ordering Part Number Flash Memory (Bytes) Analog Comparators 2 2 2 2 Temperature Sensor 10-bit 200ksps ADC Voltage Reference Digital Port I/Os Timers (16-bit) Enhanced SPI MIPS (Peak) SMBus/I2C C8051F340-GQ 48 64k 4352 C8051F341-GQ 48 32k 2304 C8051F342-GQ 48 64k 4352 C8051F343-GQ 48 32k 2304 C8051F344-GQ 25 64k 4352 C8051F345-GQ 25 32k 2304 C8051F346-GQ 25 64k 4352 C8051F347-GQ 25 32k 2304 - 2 2 1 1 2 2 1 1 4 4 4 4 4 4 4 4 40 40 25 25 40 40 25 25 - 2 TQFP48 2 TQFP48 LQFP32 LQFP32 2 TQFP48 2 TQFP48 LQFP32 LQFP32 18 Rev. 0.5 Package UARTs RAM C8051F340/1/2/3/4/5/6/7 C2D C2CK/RST Debug / Programming Hardware Reset Port I/O Configuration Digital Peripherals UART0 Port 0 Drivers UART1 Timers 0, 1, 2, 3 PCA/WDT Power-On Reset Supply Monitor VDD CIP-51 8051 Controller Core 64/32k Byte ISP FLASH Program Memory 256 Byte RAM P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6/XTAL1 P0.7/XTAL2 P1.0 P1.1 P1.2 P1.3 P1.4/CNVSTR P1.5/VREF P1.6 P1.7 P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P3.0 P3.1 P3.2 P3.3 P3.4 P3.5 P3.6 P3.7 P4.0 P4.1 P4.2 P4.3 P4.4 P4.5 P4.6 P4.7 Priority Crossbar Decoder Port 1 Drivers Power Net VREG SMBus 4/2k Byte XRAM SPI Crossbar Control Port 2 Drivers Voltage Regulator GND System Clock Setup XTAL1 XTAL2 External Oscillator Internal Oscillator Clock Recovery Clock Multiplier SFR Bus External Memory Interface P1 Port 3 Drivers Control Address Data P2 / P3 P4 Low Freq. Oscillator Port 4 Drivers CP0 Analog Peripherals VREF + + - USB Peripheral D+ D- VDD VREF CP1 VBUS Full / Low Speed Transceiver Controller 1k Byte RAM 10-bit 200ksps ADC A M U X 2 Comparators VDD Temp Sensor AIN0 - AIN19 Figure 1.1. C8051F340/1/4/5 Block Diagram Rev. 0.5 19 C8051F340/1/2/3/4/5/6/7 C2D C2CK/RST Debug / Programming Hardware Port I/O Configuration Digital Peripherals UART0 Port 0 Drivers Reset Power-On Reset Supply Monitor VDD CIP-51 8051 Controller Core 64/32 kB ISP FLASH Program Memory 256 Byte RAM SMBus 4/2 kB XRAM SPI Crossbar Control Timers 0, 1, 2, 3 PCA/WDT Priority Crossbar Decoder P0.0 P0.1 P0.2/XTAL1 P0.3/XTAL2 P0.4 P0.5 P0.6/CNVSTR P0.7/VREF P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P3.0/C2D Port 1 Drivers Power Net VREG Voltage Regulator Port 2 Drivers GND System Clock Setup XTAL1 XTAL2 External Oscillator Internal Oscillator Clock Recovery Clock Multiplier SFR Bus Port 3 Drivers Low Freq. Oscillator* Analog Peripherals VREF CP0 VREF CP1 + + - USB Peripheral D+ D- VDD VBUS Full / Low Speed Transceiver Controller 10-bit 200 ksps ADC A M U X 2 Comparators VDD Temp Sensor AIN0 - AIN20 1 kB RAM *Low Frequency Oscillator option not available on C8051F346/7 Figure 1.2. C8051F342/3/6/7 Block Diagram 20 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 1.1. CIP-51TM Microcontroller Core 1.1.1. Fully 8051 Compatible The C8051F340/1/2/3/4/5/6/7 family utilizes Silicon Labs' proprietary CIP-51 microcontroller core. The CIP-51 is fully compatible with the MCS-51TM instruction set; standard 803x/805x assemblers and compilers can be used to develop software. The CIP-51 core offers all the peripherals included with a standard 8052, including four 16-bit counter/timers, two full-duplex UARTs with extended baud rate configuration, an enhanced SPI port, up to 4352 Bytes of on-chip RAM, 128 byte Special Function Register (SFR) address space, and up to 40 I/O pins. 1.1.2. Improved Throughput The CIP-51 employs a pipelined architecture that greatly increases its instruction throughput over the standard 8051 architecture. In a standard 8051, all instructions except for MUL and DIV take 12 or 24 system clock cycles to execute with a maximum system clock of 12-to-24 MHz. By contrast, the CIP-51 core executes 70% of its instructions in one or two system clock cycles, with only four instructions taking more than four system clock cycles. The CIP-51 has a total of 109 instructions. The table below shows the total number of instructions listed by the required execution time. Clocks to Execute Number of Instructions 1 26 2 50 2/3 5 3 14 3/4 7 4 3 4/5 1 5 2 8 1 1.1.3. Additional Features The C8051F340/1/2/3/4/5/6/7 SoC family includes several key enhancements to the CIP-51 core and peripherals to improve performance and ease of use in end applications. The extended interrupt handler provides 16 interrupt sources into the CIP-51 (as opposed to 7 for the standard 8051), allowing numerous analog and digital peripherals to interrupt the controller. An interrupt driven system requires less intervention by the MCU, giving it more effective throughput. The extra interrupt sources are very useful when building multi-tasking, real-time systems. Nine reset sources are available: power-on reset circuitry (POR), an on-chip VDD monitor (forces reset when power supply voltage drops below VRST as given in Table 11.1 on page 107), the USB controller (USB bus reset or a VBUS transition), a Watchdog Timer, a Missing Clock Detector, a voltage level detection from Comparator0, a forced software reset, an external reset pin, and an errant Flash read/write protection circuit. Each reset source except for the POR, Reset Input Pin, or Flash error may be disabled by the user in software. The WDT may be permanently enabled in software after a power-on reset during MCU initialization. The high-speed internal oscillator is factory calibrated to 12 MHz 1.5%. A clock recovery mechanism allows the internal oscillator to be used with the 4x Clock Multiplier as the USB clock source in Full Speed mode; the internal oscillator can also be used as the USB clock source in Low Speed mode. External oscillators may also be used with the 4x Clock Multiplier. An internal low-frequency oscillator is also included to aid applications where power savings are critical. Also included is an external oscillator drive circuit, which allows an external crystal, ceramic resonator, capacitor, RC, or CMOS clock source to generate the system clock. The system clock may be configured to use ether of the internal oscillators, an external oscillator, or the Clock Multiplier output divided by 2. If desired, the system clock source may be switched on-the-fly between oscillator sources. The low-frequency internal oscillator or an external oscillator can be useful in low power applications, allowing the MCU to run from a slow (power saving) external clock source, while periodically switching to a higher-speed clock source when fast throughput is necessary. Rev. 0.5 21 C8051F340/1/2/3/4/5/6/7 VDD Supply Monitor + Enable Px.x Px.x Comparator 0 + C0RSEF Power On Reset '0' (wired-OR) /RST Missing Clock Detector (oneshot) EN PCA WDT Reset Funnel Software Reset (SWRSF) MCD Enable Internal HF Oscillator Clock Multiplier System Clock WDT Enable Internal LF Oscillator XTAL1 XTAL2 External Oscillator Drive CIP-51 Microcontroller Core Extended Interrupt Handler USB Controller System Reset Enable EN Errant FLASH Operation VBUS Transition Clock Select Figure 1.3. On-Chip Clock and Reset 22 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 1.2. On-Chip Memory The CIP-51 has a standard 8051 program and data address configuration. It includes 256 bytes of data RAM, with the upper 128 bytes dual-mapped. Indirect addressing accesses the upper 128 bytes of general purpose RAM, and direct addressing accesses the 128 byte SFR address space. The lower 128 bytes of RAM are accessible via direct and indirect addressing. The first 32 bytes are addressable as four banks of general purpose registers, and the next 16 bytes can be byte addressable or bit addressable. Program memory consists of 64 k (C8051F340/2/4/6) or 32 k (C8051F341/3/5/7) bytes of Flash. This memory may be reprogrammed in-system in 512 byte sectors, and requires no special off-chip programming voltage. On-chip XRAM is also included for the entire device family. The 64 k FLASH devices (C8051F340/2/4/6) have 4 k of XRAM space. The 32 k Flash devices (C8051F341/3/5/7) have 2 k of XRAM space. A separate 1 k Bytes of USB FIFO RAM is also included on all devices. See Figure 1.4 for the MCU system memory map of the 64k Flash devices. Note that on the 64k devices, 1024 bytes at locations 0xFC00 to 0xFFFF are reserved. PROGRAM/DATA MEMORY (FLASH) 0xFFFF 0xFC00 0xFBFF 0xFF RESERVED 0x80 0x7F DATA MEMORY (RAM) INTERNAL DATA ADDRESS SPACE Upper 128 RAM (Indirect Addressing Only) (Direct and Indirect Addressing) Special Function Register's (Direct Addressing Only) FLASH (In-System Programmable in 512 Byte Sectors) 0x30 0x2F 0x20 0x1F 0x00 Bit Addressable General Purpose Registers Lower 128 RAM (Direct and Indirect Addressing) EXTERNAL DATA ADDRESS SPACE 0x0000 0xFFFF Off-Chip XRAM (Available only on devices with EMIF) 0x1000 0x0FFF XRAM - 4096 Bytes (Accessable using MOVX instruction) USB FIFOs 1024 Bytes 0x07FF 0x0400 0x0000 Figure 1.4. On-Chip Memory Map for 64kB Devices (C8051F340/2/4/6) Rev. 0.5 23 C8051F340/1/2/3/4/5/6/7 1.3. Universal Serial Bus Controller The Universal Serial Bus Controller (USB0) is a USB 2.0 compliant Full or Low Speed function with integrated transceiver and endpoint FIFO RAM. A total of eight endpoint pipes are available: a bi-directional control endpoint (Endpoint0) and three pairs of IN/OUT endpoints (Endpoints1-3 IN/OUT). A 1k Byte block of RAM is used for USB FIFO space. This FIFO space is distributed among Endpoints0-3; Endpoint1-3 FIFO slots can be configured as IN, OUT, or both IN and OUT (split mode). The maximum FIFO size is 512 bytes (Endpoint3). USB0 can be operated as a Full or Low Speed function. On-chip 4x Clock Multiplier and clock recovery circuitry allow both Full and Low Speed options to be implemented with the on-chip precision oscillator as the USB clock source. An external oscillator source can also be used with the 4x Clock Multiplier to generate the USB clock. The CPU clock source is independent of the USB clock. The USB Transceiver is USB 2.0 compliant, and includes on-chip matching and pull-up resistors. The pull-up resistors can be enabled/disabled in software, and will appear on the D+ or D- pin according to the software-selected speed setting (Full or Low Speed). Transceiver Serial Interface Engine (SIE) Endpoint0 VDD D+ Data Transfer Control DIN/OUT USB Control, Status, and Interrupt Registers CIP-51 Core Endpoint1 Endpoint2 IN IN IN Endpoint3 OUT OUT OUT USB FIFOs (1k RAM) Figure 1.5. USB Controller Block Diagram 24 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 1.4. Voltage Regulator C8051F340/1/2/3/4/5/6/7 devices include a voltage regulator (REG0). When enabled, the REG0 output appears on the VDD pin, and can also be used to power other external devices. REG0 can be enabled/disabled by software. 1.5. On-Chip Debug Circuitry The C8051F340/1/2/3/4/5/6/7 devices include on-chip Silicon Labs 2-Wire (C2) debug circuitry that provides non-intrusive, full speed, in-circuit debugging of the production part installed in the end application. Silicon Labs' debugging system supports inspection and modification of memory and registers, breakpoints, and single stepping. No additional target RAM, program memory, timers, or communications channels are required. All the digital and analog peripherals are functional and work correctly while debugging. All the peripherals (except for the USB, ADC, and SMBus) are stalled when the MCU is halted, during single stepping, or at a breakpoint in order to keep them synchronized. The C8051F340DK development kit provides all the hardware and software necessary to develop application code and perform in-circuit debugging with the C8051F340/1/2/3/4/5/6/7 MCUs. The kit includes software with a developer's studio and debugger, 8051 assembler and linker, evaluation `C' compiler, and a debug adapter. It also has a target application board with the C8051F340 MCU installed, the necessary cables for connection to a PC, and a wall-mount power supply. The development kit contents may also be used to program and debug the device on the production PCB using the appropriate connections for the programming pins. The Silicon Labs IDE interface is a vastly superior developing and debugging configuration, compared to standard MCU emulators that use on-board "ICE Chips" and require the MCU in the application board to be socketed. Silicon Labs' debug paradigm increases ease of use and preserves the performance of the precision analog peripherals. Rev. 0.5 25 C8051F340/1/2/3/4/5/6/7 1.6. Programmable Digital I/O and Crossbar C8051F340/1/4/5 devices include 40 I/O pins (five byte-wide Ports); C8051F342/3/6/7 devices include 25 I/O pins (three byte-wide Ports, and a 1-bit-wide Port). The C8051F340/1/2/3/4/5/6/7 Ports behave like typical 8051 Ports with a few enhancements. Each Port pin may be configured as an analog input or a digital I/O pin. Pins selected as digital I/Os may additionally be configured for push-pull or open-drain output. The "weak pull-ups" that are fixed on typical 8051 devices may be globally disabled, providing power savings capabilities. The Digital Crossbar allows mapping of internal digital system resources to Port I/O pins (See Figure 1.6). On-chip counter/timers, serial buses, HW interrupts, comparator outputs, and other digital signals in the controller can be configured to appear on the Port I/O pins specified in the Crossbar Control registers. This allows the user to select the exact mix of general purpose Port I/O and digital resources needed for the end application. XBR0, XBR1, XBR2, PnSKIP Registers PnMDOUT, PnMDIN Registers Priority Decoder Highest Priority UART0 SPI SMBus (Internal Digital Signals) CP0 Outputs CP1 Outputs SYSCLK 8 PCA T0, T1 Lowest Priority UART1* 6 2 8 2 8 P0 (P0.0-P0.7) 8 (Port Latches) P1 (P1.0-P1.7) 8 P2 (P2.0-P2.7) 8 P3 (P3.0-P3.7*) P3 I/O Cells P3.0 P3.7* P2 I/O Cells P2.0 P2.7 2 4 8 2 2 2 P0 I/O Cells P0.0 P0.7 P1.0 P1.7 Digital Crossbar 8 P1 I/O Cells *Note: P3.1-P3.7 and UART1 only available on 48-pin package Figure 1.6. Digital Crossbar Diagram 26 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 1.7. Serial Ports The C8051F340/1/2/3/4/5/6/7 Family includes an SMBus/I2C interface, full-duplex UARTs, and an Enhanced SPI interface. Each of the serial buses is fully implemented in hardware and makes extensive use of the CIP-51's interrupts, thus requiring very little CPU intervention. 1.8. Programmable Counter Array An on-chip Programmable Counter/Timer Array (PCA) is included in addition to the four 16-bit general purpose counter/timers. The PCA consists of a dedicated 16-bit counter/timer time base with five programmable capture/compare modules. The PCA clock is derived from one of six sources: the system clock divided by 12, the system clock divided by 4, Timer 0 overflows, a dedicated External Clock Input (ECI), the system clock, or the external oscillator clock source divided by 8. The external clock source selection is useful for real-time clock functionality, where the PCA may be clocked by an external source while the internal oscillator drives the system clock. Each capture/compare module can be configured to operate in one of six modes: Edge-Triggered Capture, Software Timer, High Speed Output, 8- or 16-bit Pulse Width Modulator, or Frequency Output. Additionally, Capture/Compare Module 4 offers watchdog timer (WDT) capabilities. Following a system reset, Module 4 is configured and enabled in WDT mode. The PCA Capture/Compare Module I/O and External Clock Input may be routed to Port I/O via the Digital Crossbar. SYSCLK/12 SYSCLK/4 Timer 0 Overflow ECI SYSCLK External Clock/8 PCA CLOCK MUX 16-Bit Counter/Timer Capture/Compare Module 0 Capture/Compare Module 1 Capture/Compare Module 2 Capture/Compare Module 3 Capture/Compare Module 4 / WDT CEX0 CEX1 CEX2 CEX3 CEX4 ECI Crossbar Port I/O Figure 1.8. PCA Block Diagram Rev. 0.5 27 C8051F340/1/2/3/4/5/6/7 1.9. 10-Bit Analog to Digital Converter The C8051F340/1/2/3/4/5/6/7 devices include an on-chip 10-bit SAR ADC with a true differential input multiplexer. With a maximum throughput of 200 ksps, the ADC offers true 10-bit linearity with an INL of 1LSB. The ADC system includes a configurable analog multiplexer that selects both positive and negative ADC inputs. Twenty (48-pin package) or twenty-one (32-pin package) of the Port I/O pins can be used as analog inputs to the ADC. Additionally, the on-chip Temperature Sensor output and the power supply voltage (VDD) are available as ADC inputs. User firmware may shut down the ADC to save power. Conversions can be started in six ways: a software command, an overflow of Timer 0, 1, 2, or 3, or an external convert start signal. This flexibility allows the start of conversion to be triggered by software events, a periodic signal (timer overflows), or external HW signals. Conversion completions are indicated by a status bit and an interrupt (if enabled). The resulting 10-bit data word is latched into the ADC data SFRs upon completion of a conversion. Window compare registers for the ADC output data can be configured to interrupt the controller when ADC data is either within or outside of a specified range. The ADC can monitor a key voltage continuously in background mode, but not interrupt the controller unless the converted data is within/outside the specified range. Analog Multiplexer * 21 Selections on 32-pin package 20 Selections on 48-pin package Configuration, Control, and Data Registers Port I/O Pins* VDD Start Conversion 000 001 010 011 100 101 AD0BUSY (W) Timer 0 Overflow Timer 2 Overflow Timer 1 Overflow CNVSTR Input Timer 3 Overflow Positive Input (AIN+) AMUX Temp Sensor (+) 10-Bit SAR (-) Port I/O Pins* VREF GND ADC End of Conversion Interrupt 16 ADC Data Registers Negative Input (AIN-) AMUX Window Compare Logic Window Compare Interrupt Figure 1.9. 10-Bit ADC Block Diagram 28 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 1.10. Comparators C8051F340/1/2/3/4/5/6/7 devices include two on-chip voltage comparators that are enabled/disabled and configured via user software. Port I/O pins may be configured as comparator inputs via a selection mux. Two comparator outputs may be routed to a Port pin if desired: a latched output and/or an unlatched (asynchronous) output. Comparator response time is programmable, allowing the user to select between high-speed and low-power modes. Positive and negative hysteresis are also configurable. Comparator interrupts may be generated on rising, falling, or both edges. When in IDLE mode, these interrupts may be used as a "wake-up" source. Comparator0 may also be configured as a reset source. Figure 1.10 shows the Comparator0 block diagram. CPnEN CPTnCN CPnOUT CPnRIF CPnFIF CPnHYP1 CPnHYP0 CPnHYN1 CPnHYN0 VDD CMXnN2 CPTnMX CMXnN1 CMXnN0 CMXnP2 CMXnP1 CMXnP0 CPn Interrupt CPn Rising-edge CPn Falling-edge CPn + Interrupt Logic CPnRIE CPnFIE + D SET Q D SET Q CPn Crossbar GND CPn - CLR Q CLR Q (SYNCHRONIZER) CPnA Reset Decision Tree (Comprator 0 Only) Port I/O connection options vary with package (32-pin or 48-pin) CPTnMD CPnRIE CPnFIE CPnMD1 CPnMD0 Figure 1.10. Comparator0 Block Diagram Rev. 0.5 29 C8051F340/1/2/3/4/5/6/7 2. Absolute Maximum Ratings Table 2.1. Absolute Maximum Ratings* Parameter Ambient temperature under bias Storage Temperature Voltage on any Port I/O Pin or /RST with respect to GND Voltage on VDD with respect to GND Maximum Total current through VDD and GND Maximum output current sunk by /RST or any Port pin Conditions Min -55 -65 -0.3 -0.3 Typ Max 125 150 5.8 4.2 500 100 Units C C V V mA mA *Note: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the devices at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. 30 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 3. Global DC Electrical Characteristics Table 3.1. Global DC Electrical Characteristics -40 to +85 C, 25 MHz System Clock unless otherwise specified. Parameter Digital Supply Voltage1 Digital Supply Current with CPU active VDD = 3.3 V, Clock = 24 MHz VDD = 3.3 V, Clock = 1 MHz VDD = 3.3 V, Clock = 32 kHz VDD = 3.3 V, Clock = 24 MHz VDD = 3.3 V, Clock = 6 MHz VDD = 3.3 V, Clock = 24 MHz VDD = 3.3 V, Clock = 1 MHz VDD = 3.3 V, Clock = 32 kHz Oscillator not running Conditions Min 2.7 Typ 3.3 15 0.7 74 TBD TBD Max 3.6 Units V mA mA A mA mA Digital Supply Current with CPU active and USB active (Full or Low Speed) Digital Supply Current with CPU inactive (not accessing Flash) 9 0.5 74 < 0.1 mA mA A A Digital Supply Current (suspend mode or shutdown mode) Digital Supply RAM Data Retention Voltage SYSCLK (System Clock)2 TSYSH (SYSCLK High Time) TSYSL (SYSCLK Low Time) Specified Operating Temperature Range 1.5 C8051F340/1/2/3 C8051F344/5/6/7 C8051F340/1/2/3 @ 50 MHz C8051F344/5/6/7 C8051F340/1/2/3 @ 50 MHz C8051F344/5/6/7 0 0 9 18 9 18 -40 +85 48 25 V MHz ns ns C Notes: 1. USB Requires 3.0 V Minimum Supply Voltage. 2. SYSCLK must be at least 32 kHz to enable debugging. Other electrical characteristics tables are found in the data sheet section corresponding to the associated peripherals. For more information on electrical characteristics for a specific peripheral, refer to the page indicated in Table 3.2. Rev. 0.5 31 C8051F340/1/2/3/4/5/6/7 Table 3.2. Index to Electrical Characteristics Tables Table Title ADC0 Electrical Characteristics Voltage Reference Electrical Characteristics Comparator Electrical Characteristics Voltage Regulator Electrical Specifications Reset Electrical Characteristics Flash Electrical Characteristics AC Parameters for External Memory Interface Oscillator Electrical Characteristics Port I/O DC Electrical Characteristics USB Transceiver Electrical Characteristics Page No. 56 58 68 69 107 111 133 145 162 191 32 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 4. Pinout and Package Definitions Table 4.1. Pin Definitions for the C8051F340/1/2/3/4/5/6/7 Name VDD Pin Numbers 48-pin 32-pin 10 6 Type Description Power In 2.7-3.6 V Power Supply Voltage Input. Power Out 3.3 V Voltage Regulator Output. See Section 8. Ground. D I/O Device Reset. Open-drain output of internal POR or VDD monitor. An external source can initiate a system reset by driving this pin low for at least 15 s. See Section 11. Clock signal for the C2 Debug Interface. Bi-directional data signal for the C2 Debug Interface. Port 3.0. See Section 15 for a complete description of Port 3. Bi-directional data signal for the C2 Debug Interface. GND /RST/ 7 13 3 9 C2CK C2D P3.0 / C2D REGIN VBUS 11 12 7 8 14 10 D I/O D I/O D I/O D I/O Power In 5 V Regulator Input. This pin is the input to the on-chip voltage regulator. D In VBUS Sense Input. This pin should be connected to the VBUS signal of a USB network. A 5 V signal on this pin indicates a USB network connection. USB D+. USB D-. D+ DP0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 8 9 6 5 4 3 2 1 48 47 4 5 2 1 32 31 30 29 28 27 D I/O D I/O D I/O or Port 0.0. See Section 15 for a complete description of Port A In 0. D I/O or Port 0.1. A In D I/O or Port 0.2. A In D I/O or Port 0.3. A In D I/O or Port 0.4. A In D I/O or Port 0.5. A In D I/O or Port 0.6. A In D I/O or Port 0.7. A In Rev. 0.5 33 C8051F340/1/2/3/4/5/6/7 Table 4.1. Pin Definitions for the C8051F340/1/2/3/4/5/6/7 (Continued) Name P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P3.0 P3.1 P3.2 Pin Numbers 48-pin 32-pin 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 - Type Description D I/O or Port 1.0. See Section 15 for a complete description of Port A In 1. D I/O or Port 1.1. A In D I/O or Port 1.2. A In D I/O or Port 1.3. A In D I/O or Port 1.4. A In D I/O or Port 1.5. A In D I/O or Port 1.6. A In D I/O or Port 1.7. A In D I/O or Port 2.0. See Section 15 for a complete description of Port A In 2. D I/O or Port 2.1. A In D I/O or Port 2.2. A In D I/O or Port 2.3. A In D I/O or Port 2.4. A In D I/O or Port 2.5. A In D I/O or Port 2.6. A In D I/O or Port 2.7. A In D I/O or Port 3.0. See Section 15 for a complete description of Port A In 3. D I/O or Port 3.1. A In D I/O or Port 3.2. A In 34 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 4.1. Pin Definitions for the C8051F340/1/2/3/4/5/6/7 (Continued) Name P3.3 P3.4 P3.5 P3.6 P3.7 P4.0 P4.1 P4.2 P4.3 P4.4 P4.5 P4.6 P4.7 Pin Numbers 48-pin 32-pin 27 26 25 24 23 22 21 20 19 18 17 16 15 - Type Description D I/O or Port 3.3. A In D I/O or Port 3.4. A In D I/O or Port 3.5. A In D I/O or Port 3.6. A In D I/O or Port 3.7. A In D I/O or Port 4.0. See Section 15 for a complete description of Port A In 4. D I/O or Port 4.1. A In D I/O or Port 4.2. A In D I/O or Port 4.3. A In D I/O or Port 4.4. A In D I/O or Port 4.5. A In D I/O or Port 4.6. A In D I/O or Port 4.7. A In Rev. 0.5 35 C8051F340/1/2/3/4/5/6/7 P0.6 P0.7 P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0 38 48 47 46 45 44 43 42 41 40 39 P0.5 P0.4 P0.3 P0.2 P0.1 P0.0 GND D+ DVDD REGIN VBUS 37 P2.1 1 2 3 4 5 6 7 8 9 10 11 12 36 35 34 33 32 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P3.0 P3.1 P3.2 P3.3 P3.4 P3.5 C8051F340/1/4/5 Top View 31 30 29 28 27 26 25 13 14 15 16 17 18 19 20 21 22 23 P4.6 P4.5 P4.4 P4.3 P4.2 P4.1 P4.0 P3.7 /RST / C2CK Figure 4.1. TQFP-48 Pinout Diagram (Top View) 36 P4.7 Rev. 0.5 P3.6 C2D 24 C8051F340/1/2/3/4/5/6/7 D D1 Table 4.2. TQFP-48 Package Dimensions A A1 A2 b D D1 e E E1 MIN 0.05 0.95 0.17 MM TYP 1.00 0.22 9.00 7.00 0.50 9.00 7.00 MAX 1.20 0.15 1.05 0.27 - E1 E 48 PIN 1 IDENTIFIER 1 e A b A1 A2 Figure 4.2. TQFP-48 Package Diagram Rev. 0.5 37 C8051F340/1/2/3/4/5/6/7 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 P1.0 26 P1.1 25 32 31 30 29 28 P0.1 P0.0 GND D+ DVDD REGIN VBUS 27 1 2 3 4 5 6 7 8 24 23 22 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0 P2.1 C8051F342/3/6/7 Top View 21 20 19 18 17 10 11 12 13 14 15 P2.3 P2.7 P2.6 P2.5 P2.4 Figure 4.3. LQFP-32 Pinout Diagram (Top View) 38 /RST / C2CK P3.0 / C2D Rev. 0.5 P2.2 16 9 C8051F340/1/2/3/4/5/6/7 D D1 Table 4.3. LQFP-32 Package Dimensions A A1 A2 b D D1 e E E1 MIN 0.05 1.35 0.30 MM TYP 1.40 0.37 9.00 7.00 0.80 9.00 7.00 MAX 1.60 0.15 1.45 0.45 - E1 E 32 PIN 1 IDENTIFIER 1 A2 A b A1 e Figure 4.4. LQFP-32 Package Diagram Rev. 0.5 39 C8051F340/1/2/3/4/5/6/7 NOTES: 40 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 5. 10-Bit ADC (ADC0) The ADC0 subsystem for the C8051F340/1/2/3/4/5/6/7 consists of two analog multiplexers (referred to collectively as AMUX0), and a 200 ksps, 10-bit successive-approximation-register ADC with integrated track-and-hold and programmable window detector. The AMUX0, data conversion modes, and window detector are all configured under software control via the Special Function Registers shown in Figure 5.1. ADC0 operates in both Single-ended and Differential modes, and may be configured to measure voltages at port pins, the Temperature Sensor output, or VDD with respect to a port pin, VREF, or GND. The connection options for AMUX0 are detailed in SFR Definition 5.1 and SFR Definition 5.2. The ADC0 subsystem is enabled only when the AD0EN bit in the ADC0 Control register (ADC0CN) is set to logic 1. The ADC0 subsystem is in low power shutdown when this bit is logic 0. AMX0P AMX0P4 AMX0P3 AMX0P2 AMX0P1 AMX0P0 AD0TM AD0EN ADC0CN AD0BUSY AD0WINT AD0CM2 AD0CM1 AD0CM0 AD0INT Port I/O Pins* VDD VDD Positive Input (AIN+) AMUX Start Conversion 000 001 010 011 100 101 AD0BUSY (W) Timer 0 Overflow Timer 2 Overflow Timer 1 Overflow CNVSTR Input Timer 3 Overflow Temp Sensor AIN+ 10-Bit SAR AIN- Port I/O Pins* VREF GND Negative Input (AIN-) AMUX AD0LJST AMX0N4 AMX0N3 AMX0N2 AMX0N1 AMX0N0 AD0SC4 AD0SC3 AD0SC2 AD0SC1 AD0SC0 SYSCLK REF ADC0H ADC ADC0L AD0WINT Window Compare Logic 32 ADC0LTH ADC0LTL ADC0GTH ADC0GTL * 21 Selections on 32-pin package 20 Selections on 48-pin package AMX0N ADC0CF Figure 5.1. ADC0 Functional Block Diagram Rev. 0.5 41 C8051F340/1/2/3/4/5/6/7 5.1. Analog Multiplexer AMUX0 selects the positive and negative inputs to the ADC. The positive input (AIN+) can be connected to individual Port pins, the on-chip temperature sensor, or the positive power supply (VDD). The negative input (AIN-) can be connected to individual Port pins, VREF, or GND. When GND is selected as the negative input, ADC0 operates in Single-ended Mode; at all other times, ADC0 operates in Differential Mode. The ADC0 input channels are selected in the AMX0P and AMX0N registers as described in SFR Definition 5.1 and SFR Definition 5.2. The conversion code format differs between Single-ended and Differential modes. The registers ADC0H and ADC0L contain the high and low bytes of the output conversion code from the ADC at the completion of each conversion. Data can be right-justified or left-justified, depending on the setting of the AD0LJST bit (ADC0CN.0). When in Single-ended Mode, conversion codes are represented as 10-bit unsigned integers. Inputs are measured from `0' to VREF x 1023/1024. Example codes are shown below for both right-justified and left-justified data. Unused bits in the ADC0H and ADC0L registers are set to `0'. Input Voltage (Single-Ended) VREF x 1023/1024 VREF x 512/1024 VREF x 256/1024 0 Right-Justified ADC0H:ADC0L (AD0LJST = 0) 0x03FF 0x0200 0x0100 0x0000 Left-Justified ADC0H:ADC0L (AD0LJST = 1) 0xFFC0 0x8000 0x4000 0x0000 When in Differential Mode, conversion codes are represented as 10-bit signed 2's complement numbers. Inputs are measured from -VREF to VREF x 511/512. Example codes are shown below for both right-justified and left-justified data. For right-justified data, the unused MSBs of ADC0H are a sign-extension of the data word. For left-justified data, the unused LSBs in the ADC0L register are set to `0'. Input Voltage (Differential) VREF x 511/512 VREF x 256/512 0 -VREF x 256/512 -VREF Right-Justified ADC0H:ADC0L (AD0LJST = 0) 0x01FF 0x0100 0x0000 0xFF00 0xFE00 Left-Justified ADC0H:ADC0L (AD0LJST = 1) 0x7FC0 0x4000 0x0000 0xC000 0x8000 Important Note About ADC0 Input Configuration: Port pins selected as ADC0 inputs should be configured as analog inputs, and should be skipped by the Digital Crossbar. To configure a Port pin for analog input, set to `0' the corresponding bit in register PnMDIN (for n = 0,1,2,3). To force the Crossbar to skip a Port pin, set to `1' the corresponding bit in register PnSKIP (for n = 0,1,2). See Section "15. Port Input/ Output" on page 147 for more Port I/O configuration details. 42 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 5.2. Temperature Sensor The temperature sensor transfer function is shown in Figure 5.2. The output voltage (VTEMP) is the positive ADC input when the temperature sensor is selected by bits AMX0P4-0 in register AMX0P. Values for the Offset and Slope parameters can be found in Table 5.1. VTEMP = (Slope x TempC) + Offset TempC = (VTEMP - Offset) / Slope Slope (V / deg C) Offset (V at 0 Celsius) Voltage Temperature Figure 5.2. Temperature Sensor Transfer Function The uncalibrated temperature sensor output is extremely linear and suitable for relative temperature measurements (see Table 5.1 for linearity specifications). For absolute temperature measurements, offset and/ or gain calibration is recommended. Typically a 1-point (offset) calibration includes the following steps: Step 1. Control/measure the ambient temperature (this temperature must be known). Step 2. Power the device, and delay for a few seconds to allow for self-heating. Step 3. Perform an ADC conversion with the temperature sensor selected as the positive input and GND selected as the negative input. Step 4. Calculate the offset characteristics, and store this value in non-volatile memory for use with subsequent temperature sensor measurements. Figure 5.3 shows the typical temperature sensor error assuming a 1-point calibration at 25 C. Note that parameters which affect ADC measurement, in particular the voltage reference value, will also affect temperature measurement. Rev. 0.5 43 C8051F340/1/2/3/4/5/6/7 5.0 0 4.0 0 3.0 0 2.0 0 5.0 0 4.0 0 3.0 0 2.0 0 1.0 0 0.0 0 Error (degrees C) 1.0 0 0.0 0-40.00 -1.00 -20.00 0.0 0 20.0 0 40.0 0 60.0 0 80.0 0 -1.00 -2.00 -2.00 -3.00 -3.00 -4.00 -4.00 -5.00 -5.00 Temperature (degrees C) Figure 5.3. Temperature Sensor Error with 1-Point Calibration (VREF = 2.40 V) 44 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 5.3. Modes of Operation ADC0 has a maximum conversion speed of 200 ksps. The ADC0 conversion clock is a divided version of the system clock, determined by the AD0SC bits in the ADC0CF register (system clock divided by (AD0SC + 1) for 0 AD0SC 31). 5.3.1. Starting a Conversion A conversion can be initiated in one of five ways, depending on the programmed states of the ADC0 Start of Conversion Mode bits (AD0CM2-0) in register ADC0CN. Conversions may be initiated by one of the following: 1. 2. 3. 4. 5. 6. Writing a `1' to the AD0BUSY bit of register ADC0CN A Timer 0 overflow (i.e., timed continuous conversions) A Timer 2 overflow A Timer 1 overflow A rising edge on the CNVSTR input signal A Timer 3 overflow Writing a `1' to AD0BUSY provides software control of ADC0 whereby conversions are performed "on-demand". During conversion, the AD0BUSY bit is set to logic 1 and reset to logic 0 when the conversion is complete. The falling edge of AD0BUSY triggers an interrupt (when enabled) and sets the ADC0 interrupt flag (AD0INT). Note: When polling for ADC conversion completions, the ADC0 interrupt flag (AD0INT) should be used. Converted data is available in the ADC0 data registers, ADC0H:ADC0L, when bit AD0INT is logic 1. Note that when Timer 2 or Timer 3 overflows are used as the conversion source, Low Byte overflows are used if Timer 2/3 is in 8-bit mode; High byte overflows are used if Timer 2/3 is in 16-bit mode. See Section "21. Timers" on page 243 for timer configuration. Important Note About Using CNVSTR: The CNVSTR input pin also functions as a Port pin. When the CNVSTR input is used as the ADC0 conversion source, the associated Port pin should be skipped by the Digital Crossbar. To configure the Crossbar to skip a pin, set the corresponding bit in the PnSKIP register to `1'. See Section "15. Port Input/Output" on page 147 for details on Port I/O configuration. Rev. 0.5 45 C8051F340/1/2/3/4/5/6/7 5.3.2. Tracking Modes The AD0TM bit in register ADC0CN controls the ADC0 track-and-hold mode. In its default state, the ADC0 input is continuously tracked, except when a conversion is in progress. When the AD0TM bit is logic 1, ADC0 operates in low-power track-and-hold mode. In this mode, each conversion is preceded by a tracking period of 3 SAR clocks (after the start-of-conversion signal). When the CNVSTR signal is used to initiate conversions in low-power tracking mode, ADC0 tracks only when CNVSTR is low; conversion begins on the rising edge of CNVSTR (see Figure 5.4). Tracking can also be disabled (shutdown) when the device is in low power standby or sleep modes. Low-power track-and-hold mode is also useful when AMUX settings are frequently changed, due to the settling time requirements described in Section "5.3.3. Settling Time Requirements" on page 47. A. ADC0 Timing for External Trigger Source CNVSTR (AD0CM[2:0]=100) 1 2 3 4 5 6 7 8 9 10 11 SAR Clocks Low Power or Convert Low Power Mode AD0TM=1 Track Convert AD0TM=0 Track or Convert Convert Track Write '1' to AD0BUSY, Timer 0, Timer 2, Timer 1, Timer 3 Overflow (AD0CM[2:0]=000, 001,010 011, 101) SAR Clocks AD0TM=1 B. ADC0 Timing for Internal Trigger Source 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Low Power or Convert 1 Track 2 3 4 5 6 7 Convert 8 9 10 11 Low Power Mode SAR Clocks AD0TM=0 Track or Convert Convert Track Figure 5.4. 10-Bit ADC Track and Conversion Example Timing 46 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 5.3.3. Settling Time Requirements When the ADC0 input configuration is changed (i.e., a different AMUX0 selection is made), a minimum tracking time is required before an accurate conversion can be performed. This tracking time is determined by the AMUX0 resistance, the ADC0 sampling capacitance, any external source resistance, and the accuracy required for the conversion. Note that in low-power tracking mode, three SAR clocks are used for tracking at the start of every conversion. For most applications, these three SAR clocks will meet the minimum tracking time requirements. Figure 5.5 shows the equivalent ADC0 input circuits for both Differential and Single-ended modes. Notice that the equivalent time constant for both input circuits is the same. The required ADC0 settling time for a given settling accuracy (SA) may be approximated by Equation 5.1. When measuring the Temperature Sensor output or VDD with respect to GND, RTOTAL reduces to RMUX. See Table 5.1 for ADC0 minimum settling time requirements. 2 t = ln ------ x R TOTAL C SAMPLE SA Equation 5.1. ADC0 Settling Time Requirements Where: SA is the settling accuracy, given as a fraction of an LSB (for example, 0.25 to settle within 1/4 LSB) t is the required settling time in seconds RTOTAL is the sum of the AMUX0 resistance and any external source resistance. n is the ADC resolution in bits (10). n Differential Mode MUX Select Single-Ended Mode MUX Select Px.x RMUX = 5k CSAMPLE = 5pF RCInput= RMUX * CSAMPLE CSAMPLE = 5pF Px.x RMUX = 5k MUX Select Px.x RMUX = 5k CSAMPLE = 5pF RCInput= RMUX * CSAMPLE Figure 5.5. ADC0 Equivalent Input Circuits Rev. 0.5 47 C8051F340/1/2/3/4/5/6/7 SFR Definition 5.1. AMX0P: AMUX0 Positive Channel Select R R R R/W R/W R/W R/W R/W Bit0 Reset Value SFR Address: Bit7 Bit6 Bit5 AMX0P4 Bit4 AMX0P3 Bit3 AMX0P2 Bit2 AMX0P1 Bit1 AMX0P0 00000000 0xBB Bits7-5: UNUSED. Read = 000b; Write = don't care. Bits4-0: AMX0P4-0: AMUX0 Positive Input Selection AMX0P4-0 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 10000 10001 10010 10011 10100 10101 - 11101 11110 11111 ADC0 Positive Input (32-pin Package) P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P3.0 P0.0 P0.1 P0.4 P0.5 RESERVED Temp Sensor VDD ADC0 Positive Input (48-pin Package) P2.0 P2.1 P2.2 P2.3 P2.5 P2.6 P3.0 P3.1 P3.4 P3.5 P3.7 P4.0 P4.3 P4.4 P4.5 P4.6 RESERVED P0.3 P0.4 P1.1 P1.2 RESERVED Temp Sensor VDD 48 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 5.2. AMX0N: AMUX0 Negative Channel Select R R R R/W R/W R/W R/W R/W Bit0 Reset Value SFR Address: Bit7 Bit6 Bit5 AMX0N4 Bit4 AMX0N3 Bit3 AMX0N2 Bit2 AMX0N1 Bit1 AMX0N0 00000000 0xBA Bits7-5: UNUSED. Read = 000b; Write = don't care. Bits4-0: AMX0N4-0: AMUX0 Negative Input Selection. Note that when GND is selected as the Negative Input, ADC0 operates in Single-ended mode. For all other Negative Input selections, ADC0 operates in Differential mode. AMX0N4-0 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 10000 10001 10010 10011 10100 10101 - 11101 11110 11111 ADC0 Negative Input (32-pin Package) P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 P3.0 P0.0 P0.1 P0.4 P0.5 RESERVED VREF GND (Single-Ended Mode) ADC0 Negative Input (48-pin Package) P2.0 P2.1 P2.2 P2.3 P2.5 P2.6 P3.0 P3.1 P3.4 P3.5 P3.7 P4.0 P4.3 P4.4 P4.5 P4.6 RESERVED P0.3 P0.4 P1.1 P1.2 RESERVED VREF GND (Single-Ended Mode) Rev. 0.5 49 C8051F340/1/2/3/4/5/6/7 SFR Definition 5.3. ADC0CF: ADC0 Configuration R/W R/W R/W R/W R/W Bit3 R/W Bit2 R/W R/W Reset Value AD0SC4 Bit7 AD0SC3 Bit6 AD0SC2 Bit5 AD0SC1 Bit4 AD0SC0 AD0LJST Bit1 Bit0 11111000 SFR Address: 0xBC Bits7-3: AD0SC4-0: ADC0 SAR Conversion Clock Period Bits. SAR Conversion clock is derived from system clock by the following equation, where AD0SC refers to the 5-bit value held in bits AD0SC4-0. SAR Conversion clock requirements are given in Table 5.1. SYSCLK AD0SC = --------------------- - 1 CLK SAR Bit2: AD0LJST: ADC0 Left Justify Select. 0: Data in ADC0H:ADC0L registers are right-justified. 1: Data in ADC0H:ADC0L registers are left-justified. Bits1-0: UNUSED. Read = 00b; Write = don't care. SFR Definition 5.4. ADC0H: ADC0 Data Word MSB R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xBE Bits7-0: ADC0 Data Word High-Order Bits. For AD0LJST = 0: Bits 7-2 are the sign extension of Bit1. Bits 1-0 are the upper 2 bits of the 10-bit ADC0 Data Word. For AD0LJST = 1: Bits 7-0 are the most-significant bits of the 10-bit ADC0 Data Word. SFR Definition 5.5. ADC0L: ADC0 Data Word LSB R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xBD Bits7-0: ADC0 Data Word Low-Order Bits. For AD0LJST = 0: Bits 7-0 are the lower 8 bits of the 10-bit Data Word. For AD0LJST = 1: Bits 7-6 are the lower 2 bits of the 10-bit Data Word. Bits 5-0 will always read `0'. 50 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 5.6. ADC0CN: ADC0 Control R/W R/W R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 (bit addressable) Reset Value SFR Address: AD0EN Bit7 AD0TM Bit6 AD0INT AD0BUSY AD0WINT AD0CM2 AD0CM1 AD0CM0 00000000 0xE8 AD0EN: ADC0 Enable Bit. 0: ADC0 Disabled. ADC0 is in low-power shutdown. 1: ADC0 Enabled. ADC0 is active and ready for data conversions. Bit6: AD0TM: ADC0 Track Mode Bit. 0: Normal Track Mode: When ADC0 is enabled, tracking is continuous unless a conversion is in progress. 1: Low-power Track Mode: Tracking Defined by AD0CM2-0 bits (see below). Bit5: AD0INT: ADC0 Conversion Complete Interrupt Flag. 0: ADC0 has not completed a data conversion since the last time AD0INT was cleared. 1: ADC0 has completed a data conversion. Bit4: AD0BUSY: ADC0 Busy Bit. Read: 0: ADC0 conversion is complete or a conversion is not currently in progress. AD0INT is set to logic 1 on the falling edge of AD0BUSY. 1: ADC0 conversion is in progress. Write: 0: No Effect. 1: Initiates ADC0 Conversion if AD0CM2-0 = 000b Bit3: AD0WINT: ADC0 Window Compare Interrupt Flag. 0: ADC0 Window Comparison Data match has not occurred since this flag was last cleared. 1: ADC0 Window Comparison Data match has occurred. Bits2-0: AD0CM2-0: ADC0 Start of Conversion Mode Select. When AD0TM = 0: 000: ADC0 conversion initiated on every write of `1' to AD0BUSY. 001: ADC0 conversion initiated on overflow of Timer 0. 010: ADC0 conversion initiated on overflow of Timer 2. 011: ADC0 conversion initiated on overflow of Timer 1. 100: ADC0 conversion initiated on rising edge of external CNVSTR. 101: ADC0 conversion initiated on overflow of Timer 3. 11x: Reserved. Bit7: When AD0TM = 1: 000: Tracking initiated on write of `1' to AD0BUSY and lasts 3 SAR clocks, followed by conversion. 001: Tracking initiated on overflow of Timer 0 and lasts 3 SAR clocks, followed by conversion. 010: Tracking initiated on overflow of Timer 2 and lasts 3 SAR clocks, followed by conversion. 011: Tracking initiated on overflow of Timer 1 and lasts 3 SAR clocks, followed by conversion. 100: ADC0 tracks only when CNVSTR input is logic low; conversion starts on rising CNVSTR edge. 101: Tracking initiated on overflow of Timer 3 and lasts 3 SAR clocks, followed by conversion. 11x: Reserved. Rev. 0.5 51 C8051F340/1/2/3/4/5/6/7 5.4. Programmable Window Detector The ADC Programmable Window Detector continuously compares the ADC0 conversion results to user-programmed limits, and notifies the system when a desired condition is detected. This is especially effective in an interrupt-driven system, saving code space and CPU bandwidth while delivering faster system response times. The window detector interrupt flag (AD0WINT in register ADC0CN) can also be used in polled mode. The ADC0 Greater-Than (ADC0GTH, ADC0GTL) and Less-Than (ADC0LTH, ADC0LTL) registers hold the comparison values. The window detector flag can be programmed to indicate when measured data is inside or outside of the user-programmed limits, depending on the contents of the ADC0 Less-Than and ADC0 Greater-Than registers. The Window Detector registers must be written with the same format (left/right justified, signed/unsigned) as that of the current ADC configuration (left/right justified, single-ended/differential). SFR Definition 5.7. ADC0GTH: ADC0 Greater-Than Data High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 11111111 SFR Address: 0xC4 Bits7-0: High byte of ADC0 Greater-Than Data Word. SFR Definition 5.8. ADC0GTL: ADC0 Greater-Than Data Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 11111111 SFR Address: 0xC3 Bits7-0: Low byte of ADC0 Greater-Than Data Word. 52 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 5.9. ADC0LTH: ADC0 Less-Than Data High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xC6 Bits7-0: High byte of ADC0 Less-Than Data Word. SFR Definition 5.10. ADC0LTL: ADC0 Less-Than Data Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xC5 Bits7-0: Low byte of ADC0 Less-Than Data Word. Rev. 0.5 53 C8051F340/1/2/3/4/5/6/7 5.4.1. Window Detector In Single-Ended Mode Figure 5.6 shows two example window comparisons for right-justified, single-ended data, with ADC0LTH:ADC0LTL = 0x0080 (128d) and ADC0GTH:ADC0GTL = 0x0040 (64d). In single-ended mode, the input voltage can range from `0' to VREF x (1023/1024) with respect to GND, and is represented by a 10-bit unsigned integer value. In the left example, an AD0WINT interrupt will be generated if the ADC0 conversion word (ADC0H:ADC0L) is within the range defined by ADC0GTH:ADC0GTL and ADC0LTH:ADC0LTL (if 0x0040 < ADC0H:ADC0L < 0x0080). In the right example, and AD0WINT interrupt will be generated if the ADC0 conversion word is outside of the range defined by the ADC0GT and ADC0LT registers (if ADC0H:ADC0L < 0x0040 or ADC0H:ADC0L > 0x0080). Figure 5.7 shows an example using left-justified data with equivalent ADC0GT and ADC0LT register settings. ADC0H:ADC0L Input Voltage (Px.x - GND) VREF x (1023/1024) 0x03FF AD0WINT not affected 0x0081 VREF x (128/1024) 0x0080 0x007F AD0WINT=1 VREF x (64/1024) 0x0041 0x0040 0x003F ADC0GTH:ADC0GTL VREF x (64/1024) ADC0LTH:ADC0LTL VREF x (128/1024) Input Voltage (Px.x - GND) VREF x (1023/1024) ADC0H:ADC0L 0x03FF AD0WINT=1 0x0081 0x0080 0x007F 0x0041 0x0040 0x003F ADC0GTH:ADC0GTL AD0WINT not affected ADC0LTH:ADC0LTL AD0WINT not affected 0 0x0000 0 0x0000 AD0WINT=1 Figure 5.6. ADC Window Compare Example: Right-Justified Single-Ended Data ADC0H:ADC0L Input Voltage (Px.x - GND) VREF x (1023/1024) 0xFFC0 AD0WINT not affected 0x2040 VREF x (128/1024) 0x2000 0x1FC0 AD0WINT=1 VREF x (64/1024) 0x1040 0x1000 0x0FC0 ADC0GTH:ADC0GTL VREF x (64/1024) ADC0LTH:ADC0LTL VREF x (128/1024) Input Voltage (Px.x - GND) VREF x (1023/1024) ADC0H:ADC0L 0xFFC0 AD0WINT=1 0x2040 0x2000 0x1FC0 0x1040 0x1000 0x0FC0 ADC0GTH:ADC0GTL AD0WINT not affected ADC0LTH:ADC0LTL AD0WINT not affected 0 0x0000 0 0x0000 AD0WINT=1 Figure 5.7. ADC Window Compare Example: Left-Justified Single-Ended Data 54 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 5.4.2. Window Detector In Differential Mode Figure 5.8 shows two example window comparisons for right-justified, differential data, with ADC0LTH:ADC0LTL = 0x0040 (+64d) and ADC0GTH:ADC0GTH = 0xFFFF (-1d). In differential mode, the measurable voltage between the input pins is between -VREF and VREF*(511/512). Output codes are represented as 10-bit 2's complement signed integers. In the left example, an AD0WINT interrupt will be generated if the ADC0 conversion word (ADC0H:ADC0L) is within the range defined by ADC0GTH:ADC0GTL and ADC0LTH:ADC0LTL (if 0xFFFF (-1d) < ADC0H:ADC0L < 0x0040 (64d)). In the right example, an AD0WINT interrupt will be generated if the ADC0 conversion word is outside of the range defined by the ADC0GT and ADC0LT registers (if ADC0H:ADC0L < 0xFFFF (-1d) or ADC0H:ADC0L > 0x0040 (+64d)). Figure 5.9 shows an example using left-justified data with equivalent ADC0GT and ADC0LT register settings. ADC0H:ADC0L Input Voltage (Px.x - Px.x) VREF x (511/512) 0x01FF AD0WINT not affected 0x0041 VREF x (64/512) 0x0040 0x003F AD0WINT=1 0x0000 VREF x (-1/512) 0xFFFF 0xFFFE ADC0GTH:ADC0GTL VREF x (-1/512) ADC0LTH:ADC0LTL VREF x (64/512) Input Voltage (Px.x - Px.x) VREF x (511/512) ADC0H:ADC0L 0x01FF AD0WINT=1 0x0041 0x0040 0x003F 0x0000 0xFFFF 0xFFFE ADC0GTH:ADC0GTL AD0WINT not affected ADC0LTH:ADC0LTL AD0WINT not affected -VREF 0x0200 -VREF 0x0200 AD0WINT=1 Figure 5.8. ADC Window Compare Example: Right-Justified Differential Data ADC0H:ADC0L Input Voltage (Px.x - Px.x) VREF x (511/512) 0x7FC0 AD0WINT not affected 0x1040 VREF x (64/512) 0x1000 0x0FC0 AD0WINT=1 0x0000 VREF x (-1/512) 0xFFC0 0xFF80 ADC0GTH:ADC0GTL VREF x (-1/512) ADC0LTH:ADC0LTL VREF x (64/512) Input Voltage (Px.x - Px.y) VREF x (511/512) ADC0H:ADC0L 0x7FC0 AD0WINT=1 0x1040 0x1000 0x0FC0 0x0000 0xFFC0 0xFF80 ADC0GTH:ADC0GTL AD0WINT not affected ADC0LTH:ADC0LTL AD0WINT not affected -VREF 0x8000 -VREF 0x8000 AD0WINT=1 Figure 5.9. ADC Window Compare Example: Left-Justified Differential Data Rev. 0.5 55 C8051F340/1/2/3/4/5/6/7 Table 5.1. ADC0 Electrical Characteristics VDD = 3.0 V, VREF = 2.40 V, -40 to +85 C unless otherwise specified Parameter Resolution Integral Nonlinearity Differential Nonlinearity Offset Error Full Scale Error Offset Temperature Coefficient Signal-to-Noise Plus Distortion Total Harmonic Distortion Spurious-Free Dynamic Range Up to the 5th harmonic 51 Guaranteed Monotonic Conditions DC Accuracy Min Typ 10 0.5 0.5 0 -1 10 52.5 -67 78 Max Units bits 1 1 LSB LSB LSB LSB ppm/C dB dB dB Dynamic Performance (10 kHz sine-wave Single-ended input, 1 dB below Full Scale, 200 ksps) Conversion Rate SAR Conversion Clock Conversion Time in SAR Clocks Track/Hold Acquisition Time Throughput Rate 10 300 200 3 MHz clocks ns ksps V V V pF C mV / C mV Analog Inputs ADC Input Voltage Range Single Ended (AIN+ - GND) Differential (AIN+ - AIN-) 0 -VREF 0 5 VREF VREF Absolute Pin Voltage with respect Single Ended or Differential to GND Input Capacitance VDD Temperature Sensor Linearity Slope2 Offset1,2 (Temp = 0 C) 1 0.1 TBD TBD TBD TBD Power Specifications Power Supply Current (VDD supOperating Mode, 200 ksps plied to ADC0) Power Supply Rejection Notes: 1. Includes ADC offset, gain, and linearity variations. 2. Represents mean one standard deviation. 400 0.3 900 A mV/V 56 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 6. Voltage Reference The Voltage reference MUX on C8051F340/1/2/3/4/5/6/7 devices is configurable to use an externally connected voltage reference, the on-chip reference voltage generator, or the power supply voltage VDD (see Figure 6.1). The REFSL bit in the Reference Control register (REF0CN) selects the reference source. For the internal reference or an external source, REFSL should be set to `0'; For VDD as the reference source, REFSL should be set to `1'. The BIASE bit enables the internal ADC bias generator, which is used by the ADC and Internal Oscillator. This enable is forced to logic 1 when either of the aforementioned peripherals is enabled. The ADC bias generator may be enabled manually by writing a `1' to the BIASE bit in register REF0CN; see SFR Definition 6.1 for REF0CN register details. The Reference bias generator (see Figure 6.1) is used by the Internal Voltage Reference, Temperature Sensor, and Clock Multiplier. The Reference bias is automatically enabled when any of the aforementioned peripherals are enabled. The electrical specifications for the voltage reference and bias circuits are given in Table 6.1. Important Note About the VREF Pin: The VREF pin, when not using the on-chip voltage reference or an external precision reference, can be configured as a GPIO Port pin. When using an external voltage reference or the on-chip reference, the VREF pin should be configured as analog pin and skipped by the Digital Crossbar. To configure the VREF pin for analog mode, set the corresponding bit in the PnMDIN register to `0'. To configure the Crossbar to skip the VREF pin, set the corresponding bit in register PnSKIP to `1'. Refer to Section "15. Port Input/Output" on page 147 for complete Port I/O configuration details. The temperature sensor connects to the ADC0 positive input multiplexer (see Section "5.1. Analog Multiplexer" on page 42 for details). The TEMPE bit in register REF0CN enables/disables the temperature sensor. While disabled, the temperature sensor defaults to a high impedance state and any ADC0 measurements performed on the sensor result in meaningless data. REF0CN REFSL TEMPE BIASE REFBE AD0EN EN IOSCEN ADC Bias To ADC, Internal Oscillator VDD External Voltage Reference Circuit VREF 0 VREF (to ADC) GND VDD 1 CLKMUL Enable TEMPE REFBE EN EN Temp Sensor To Analog Mux R1 EN Reference Bias To Clock Multiplier, Temp Sensor Internal Reference Figure 6.1. Voltage Reference Functional Block Diagram Rev. 0.5 57 C8051F340/1/2/3/4/5/6/7 SFR Definition 6.1. REF0CN: Reference Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 Bit6 Bit5 Bit4 REFSL Bit3 TEMPE Bit2 BIASE Bit1 REFBE Bit0 00000000 SFR Address: 0xD1 Bits7-3: UNUSED. Read = 00000b; Write = don't care. Bit3: REFSL: Voltage Reference Select. This bit selects the source for the internal voltage reference. 0: VREF pin used as voltage reference. 1: VDD used as voltage reference. Bit2: TEMPE: Temperature Sensor Enable Bit. 0: Internal Temperature Sensor off. 1: Internal Temperature Sensor on. Bit1: BIASE: Internal Analog Bias Generator Enable Bit. 0: Internal Bias Generator off. 1: Internal Bias Generator on. Bit0: REFBE: Internal Reference Buffer Enable Bit. 0: Internal Reference Buffer disabled. 1: Internal Reference Buffer enabled. Internal voltage reference driven on the VREF pin. Table 6.1. Voltage Reference Electrical Characteristics VDD = 3.0 V; -40 to +85 C Unless Otherwise Specified Parameter Conditions Min Internal Reference (REFBE = 1) 25 C ambient 2.38 Typ 2.44 Max 2.50 10 Units V mA ppm/C ppm/A ms s s ppm/V Output Voltage VREF Short-Circuit Current VREF Temperature Coefficient Load Regulation Load = 0 to 200 A to GND 4.7 F tantalum, 0.1 F ceramic VREF Turn-on Time 1 bypass VREF Turn-on Time 2 0.1 F ceramic bypass VREF Turn-on Time 3 no bypass cap Power Supply Rejection External Reference (REFBE = 0) Input Voltage Range Input Current Sample Rate = 200 ksps; VREF = 3.0 V Bias Generators BIASE = `1' 15 1.5 2 20 10 140 0 12 VDD V A ADC Bias Generator Reference Bias Generator 100 40 A A 58 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 7. Comparators C8051F340/1/2/3/4/5/6/7 devices include two on-chip programmable voltage Comparators. A block diagram of the comparators is shown in Figure 7.1, where "n" is the comparator number (0 or 1). The two Comparators operate identically with the following exceptions: (1) Their input selections differ, and (2) Comparator0 can be used as a reset source. For input selection details, refer to SFR Definition 7.2 and SFR Definition 7.5. Each Comparator offers programmable response time and hysteresis, an analog input multiplexer, and two outputs that are optionally available at the Port pins: a synchronous "latched" output (CP0, CP1), or an asynchronous "raw" output (CP0A, CP1A). The asynchronous signal is available even when the system clock is not active. This allows the Comparators to operate and generate an output with the device in STOP mode. When assigned to a Port pin, the Comparator outputs may be configured as open drain or push-pull (see Section "15.2. Port I/O Initialization" on page 151). Comparator0 may also be used as a reset source (see Section "11.5. Comparator0 Reset" on page 104). The Comparator0 inputs are selected in the CPT0MX register (SFR Definition 7.2). The CMX0P1-CMX0P0 bits select the Comparator0 positive input; the CMX0N1-CMX0N0 bits select the Comparator0 negative input. The Comparator1 inputs are selected in the CPT1MX register (SFR Definition 7.5). The CMX1P1-CMX1P0 bits select the Comparator1 positive input; the CMX1N1-CMX1N0 bits select the Comparator1 negative input. Important Note About Comparator Inputs: The Port pins selected as Comparator inputs should be configured as analog inputs in their associated Port configuration register, and configured to be skipped by the Crossbar (for details on Port configuration, see Section "15.3. General Purpose Port I/O" on page 154). Rev. 0.5 59 C8051F340/1/2/3/4/5/6/7 CPnEN CPnOUT CPnRIF CPnFIF CPnHYP1 CPnHYP0 CPnHYN1 CPnHYN0 CPTnMX CMXnN2 CMXnN1 CMXnN0 CMXnP2 CMXnP1 CMXnP0 CPTnCN VDD CPn Interrupt CPn Rising-edge CPn Falling-edge CPn + Interrupt Logic CPnRIE CPnFIE + D SET Q D SET Q CPn Crossbar GND CPn - CLR Q CLR Q (SYNCHRONIZER) CPnA Reset Decision Tree (Comprator 0 Only) Port I/O connection options vary with package (32-pin or 48-pin) CPTnMD CPnRIE CPnFIE CPnMD1 CPnMD0 Figure 7.1. Comparator Functional Block Diagram Comparator outputs can be polled in software, used as an interrupt source, and/or routed to a Port pin. When routed to a Port pin, Comparator outputs are available asynchronous or synchronous to the system clock; the asynchronous output is available even in STOP mode (with no system clock active). When disabled, the Comparator output (if assigned to a Port I/O pin via the Crossbar) defaults to the logic low state, and supply current falls to less than 100 nA. See Section "15.1. Priority Crossbar Decoder" on page 149 for details on configuring Comparator outputs via the digital Crossbar. Comparator inputs can be externally driven from -0.25 V to (VDD) + 0.25 V without damage or upset. The complete Comparator electrical specifications are given in Table 7.1. Comparator response time may be configured in software via the CPTnMD registers (see SFR Definition 7.3 and SFR Definition 7.6). Selecting a longer response time reduces the Comparator supply current. See Table 7.1 for complete timing and supply current specifications. 60 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 VIN+ VIN- CP0+ CP0- + CP0 _ OUT CIRCUIT CONFIGURATION Positive Hysteresis Voltage (Programmed with CP0HYP Bits) VIN- INPUTS VIN+ Negative Hysteresis Voltage (Programmed by CP0HYN Bits) VOH OUTPUT VOL Negative Hysteresis Disabled Positive Hysteresis Disabled Maximum Positive Hysteresis Maximum Negative Hysteresis Figure 7.2. Comparator Hysteresis Plot Comparator hysteresis is programmed using Bits3-0 in the Comparator Control Register CPTnCN (shown in SFR Definition 7.1 and SFR Definition 7.4). The amount of negative hysteresis voltage is determined by the settings of the CPnHYN bits. As shown in Figure 7.2, various levels of negative hysteresis can be programmed, or negative hysteresis can be disabled. In a similar way, the amount of positive hysteresis is determined by the setting the CPnHYP bits. Comparator interrupts can be generated on both rising-edge and falling-edge output transitions. (For Interrupt enable and priority control, see Section "9.3. Interrupt Handler" on page 87.) The CPnFIF flag is set to `1' upon a Comparator falling-edge, and the CPnRIF flag is set to `1' upon the Comparator rising-edge. Once set, these bits remain set until cleared by software. The output state of the Comparator can be obtained at any time by reading the CPnOUT bit. The Comparator is enabled by setting the CPnEN bit to `1', and is disabled by clearing this bit to `0'. Rev. 0.5 61 C8051F340/1/2/3/4/5/6/7 SFR Definition 7.1. CPT0CN: Comparator0 Control R/W R R/W R/W R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value SFR Address: CP0EN Bit7 CP0OUT Bit6 CP0RIF Bit5 CP0FIF Bit4 CP0HYP1 CP0HYP0 CP0HYN1 CP0HYN0 00000000 0x9B CP0EN: Comparator0 Enable Bit. 0: Comparator0 Disabled. 1: Comparator0 Enabled. Bit6: CP0OUT: Comparator0 Output State Flag. 0: Voltage on CP0+ < CP0-. 1: Voltage on CP0+ > CP0-. Bit5: CP0RIF: Comparator0 Rising-Edge Flag. 0: No Comparator0 Rising Edge has occurred since this flag was last cleared. 1: Comparator0 Rising Edge has occurred. Bit4: CP0FIF: Comparator0 Falling-Edge Flag. 0: No Comparator0 Falling-Edge has occurred since this flag was last cleared. 1: Comparator0 Falling-Edge Interrupt has occurred. Bits3-2: CP0HYP1-0: Comparator0 Positive Hysteresis Control Bits. 00: Positive Hysteresis Disabled. 01: Positive Hysteresis = 5 mV. 10: Positive Hysteresis = 10 mV. 11: Positive Hysteresis = 20 mV. Bits1-0: CP0HYN1-0: Comparator0 Negative Hysteresis Control Bits. 00: Negative Hysteresis Disabled. 01: Negative Hysteresis = 5 mV. 10: Negative Hysteresis = 10 mV. 11: Negative Hysteresis = 20 mV. Bit7: 62 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 7.2. CPT0MX: Comparator0 MUX Selection R/W R/W Bit6 R/W Bit5 R/W Bit4 R/W R/W R/W R/W Bit0 Reset Value SFR Address: Bit7 CMX0N2 CMX0N1 CMX0N0 Bit3 CMX0P2 Bit2 CMX0P1 Bit1 CMX0P0 00000000 0x9F Bit7: UNUSED. Read = 0b, Write = don't care. Bits6-4: CMX0N2-CMX0N0: Comparator0 Negative Input MUX Select. These bits select which Port pin is used as the Comparator0 negative input. CMX0N1 CMX0N1 CMX0N0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 Negative Input (32-pin Package) P1.1 P1.5 P2.1 P2.5 P0.1 Negative Input (48-pin Package) P2.1 P2.6 P3.5 P4.4 P0.4 Bit3: UNUSED. Read = 0b, Write = don't care. Bits2-0: CMX0P2-CMX0P0: Comparator0 Positive Input MUX Select. These bits select which Port pin is used as the Comparator0 positive input. CMX0P1 CMX0P1 CMX0P0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 Positive Input (32-pin Package) P1.0 P1.4 P2.0 P2.4 P0.0 Positive Input (48-pin Package) P2.0 P2.5 P3.4 P4.3 P0.3 Note that the port pins used by the comparator depend on the package type (32-pin or 48-pin). Rev. 0.5 63 C8051F340/1/2/3/4/5/6/7 SFR Definition 7.3. CPT0MD: Comparator0 Mode Selection R/W R/W R/W R/W R/W R/W R/W Bit1 R/W Bit0 Reset Value SFR Address: Bit7 Bit6 CP0RIE Bit5 CP0FIE Bit4 Bit3 Bit2 CP0MD1 CP0MD0 00000010 0x9D Bits7-6: UNUSED. Read = 00b. Write = don't care. Bit5: CP0RIE: Comparator0 Rising-Edge Interrupt Enable. 0: Comparator0 rising-edge interrupt disabled. 1: Comparator0 rising-edge interrupt enabled. Bit4: CP0FIE: Comparator0 Falling-Edge Interrupt Enable. 0: Comparator0 falling-edge interrupt disabled. 1: Comparator0 falling-edge interrupt enabled. Bits3-2: UNUSED. Read = 00b. Write = don't care. Bits1-0: CP0MD1-CP0MD0: Comparator0 Mode Select These bits select the response time for Comparator0. Mode 0 1 2 3 CP0MD1 0 0 1 1 CP0MD0 0 1 0 1 CP0 Response Time* Fastest Response Lowest Power * See Table 7.1 for response time parameters. 64 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 7.4. CPT1CN: Comparator1 Control R/W R R/W R/W R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value SFR Address: CP1EN Bit7 CP1OUT Bit6 CP1RIF Bit5 CP1FIF Bit4 CP1HYP1 CP1HYP0 CP1HYN1 CP1HYN0 00000000 0x9A CP1EN: Comparator1 Enable Bit. 0: Comparator1 Disabled. 1: Comparator1 Enabled. Bit6: CP1OUT: Comparator1 Output State Flag. 0: Voltage on CP1+ < CP1-. 1: Voltage on CP1+ > CP1-. Bit5: CP1RIF: Comparator1 Rising-Edge Flag. 0: No Comparator1 Rising Edge has occurred since this flag was last cleared. 1: Comparator1 Rising Edge has occurred. Bit4: CP1FIF: Comparator1 Falling-Edge Flag. 0: No Comparator1 Falling-Edge has occurred since this flag was last cleared. 1: Comparator1 Falling-Edge has occurred. Bits3-2: CP1HYP1-0: Comparator1 Positive Hysteresis Control Bits. 00: Positive Hysteresis Disabled. 01: Positive Hysteresis = 5 mV. 10: Positive Hysteresis = 10 mV. 11: Positive Hysteresis = 20 mV. Bits1-0: CP1HYN1-0: Comparator1 Negative Hysteresis Control Bits. 00: Negative Hysteresis Disabled. 01: Negative Hysteresis = 5 mV. 10: Negative Hysteresis = 10 mV. 11: Negative Hysteresis = 20 mV. Bit7: Rev. 0.5 65 C8051F340/1/2/3/4/5/6/7 SFR Definition 7.5. CPT1MX: Comparator1 MUX Selection R/W R/W Bit6 R/W Bit5 R/W Bit4 R/W R/W R/W R/W Bit0 Reset Value SFR Address: Bit7 CMX1N2 CMX1N1 CMX1N0 Bit3 CMX1P2 Bit2 CMX1P1 Bit1 CMX1P0 00000000 0x9E Bit7: UNUSED. Read = 0b, Write = don't care. Bits6-4: CMX1N2-CMX1N0: Comparator1 Negative Input MUX Select. These bits select which Port pin is used as the Comparator1 negative input. CMX1N2 CMX1N1 CMX1N0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 Negative Input (32-pin Package) P1.3 P1.7 P2.3 P2.7 P0.5 Negative Input (48-pin Package) P2.3 P3.1 P4.0 P4.6 P1.2 Bit3: UNUSED. Read = 0b, Write = don't care. Bits2-0: CMX1P1-CMX1P0: Comparator1 Positive Input MUX Select. These bits select which Port pin is used as the Comparator1 positive input. CMX1P2 CMX1P1 CMX1P0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 Positive Input (32-pin Package) P1.2 P1.6 P2.2 P2.6 P0.4 Positive Input (48-pin Package) P2.2 P3.0 P3.7 P4.5 P1.1 Note that the port pins used by the comparator depend on the package type (32-pin or 48-pin). 66 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 7.6. CPT1MD: Comparator1 Mode Selection R/W R/W R/W R/W R/W R/W R/W Bit1 R/W Bit0 Reset Value SFR Address: Bit7 Bit6 CP1RIE Bit5 CP1FIE Bit4 Bit3 Bit2 CP1MD1 CP1MD0 00000010 0x9C Bits7-6: UNUSED. Read = 00b, Write = don't care. Bit5: CP1RIE: Comparator1 Rising-Edge Interrupt Enable. 0: Comparator1 rising-edge interrupt disabled. 1: Comparator1 rising-edge interrupt enabled. Bit4: CP1FIE: Comparator1 Falling-Edge Interrupt Enable. 0: Comparator1 falling-edge interrupt disabled. 1: Comparator1 falling-edge interrupt enabled. Bits1-0: CP1MD1-CP1MD0: Comparator1 Mode Select. These bits select the response time for Comparator1. Mode 0 1 2 3 CP1MD1 0 0 1 1 CP1MD0 0 1 0 1 CP1 Response Time* Fastest Response Lowest Power * See Table 7.1 for response time parameters. Rev. 0.5 67 C8051F340/1/2/3/4/5/6/7 Table 7.1. Comparator Electrical Characteristics VDD = 3.0 V, -40 to +85 C unless otherwise noted. All specifications apply to both Comparator0 and Comparator1 unless otherwise noted. Parameter Response Time: Mode 0, Vcm* = 1.5 V Response Time: Mode 1, Vcm* = 1.5 V Response Time: Mode 2, Vcm* = 1.5 V Response Time: Mode 3, Vcm* = 1.5 V Common-Mode Rejection Ratio Positive Hysteresis 1 Positive Hysteresis 2 Positive Hysteresis 3 Positive Hysteresis 4 Negative Hysteresis 1 Negative Hysteresis 2 Negative Hysteresis 3 Negative Hysteresis 4 Inverting or Non-Inverting Input Voltage Range Input Capacitance Input Bias Current Input Offset Voltage -5 CP0HYP1-0 = 00 CP0HYP1-0 = 01 CP0HYP1-0 = 10 CP0HYP1-0 = 11 CP0HYN1-0 = 00 CP0HYN1-0 = 01 CP0HYN1-0 = 10 CP0HYN1-0 = 11 2 7 15 -0.25 3 0.001 +5 0.1 10 Mode 0 Supply Current at DC Mode 1 Mode 2 Mode 3 *Note: Vcm is the common-mode voltage on CP0+ and CP0-. Conditions CP0+ - CP0- = 100 mV CP0+ - CP0- = -100 mV CP0+ - CP0- = 100 mV CP0+ - CP0- = -100 mV CP0+ - CP0- = 100 mV CP0+ - CP0- = -100 mV CP0+ - CP0- = 100 mV CP0+ - CP0- = -100 mV Min Typ 100 250 175 500 320 1100 1050 5200 1.5 0 Max Units ns ns ns ns ns ns ns ns 4 1 10 20 30 1 10 20 30 VDD + 0.25 mV/V mV mV mV mV mV mV mV mV V pF nA mV mV/V s A A A A 2 7 15 5 10 20 0 5 10 20 Power Supply Power Supply Rejection Power-up Time 7.6 3.2 1.3 0.4 68 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 8. Voltage Regulator (REG0) C8051F340/1/2/3/4/5/6/7 devices include a voltage regulator (REG0). When enabled, the REG0 output appears on the VDD pin and can be used to power external devices. REG0 can be enabled/disabled by software using bit REGEN in register REG0CN. See Table 8.1 for REG0 electrical characteristics. Note that the VBUS signal must be connected to the VBUS pin when using the device in a USB network. The VBUS signal should only be connected to the REGIN pin when operating the device as a bus-powered function. REG0 configuration options are shown in Figure 8.1-Figure 8.4. 8.1. Regulator Mode Selection REG0 offers a low power mode intended for use when the device is in suspend mode. In this low power mode, the REG0 output remains as specified; however the REG0 dynamic performance (response time) is degraded. See Table 8.1 for normal and low power mode supply current specifications. The REG0 mode selection is controlled via the REGMOD bit in register REG0CN. 8.2. VBUS Detection When the USB Function Controller is used (see section Section "16. Universal Serial Bus Controller (USB0)" on page 163), the VBUS signal should be connected to the VBUS pin. The VBSTAT bit (register REG0CN) indicates the current logic level of the VBUS signal. If enabled, a VBUS interrupt will be generated when the VBUS signal matches the polarity selected by the VBPOL bit in register REG0CN. The VBUS interrupt is level-sensitive, and has no associated interrupt pending flag. The VBUS interrupt will be active as long as the VBUS signal matches the polarity selected by VBPOL. See Table 8.1 for VBUS input parameters. Important Note: When USB is selected as a reset source, a system reset will be generated when the VBUS signal matches the polarity selected by the VBPOL bit. See Section "11. Reset Sources" on page 101 for details on selecting USB as a reset source Table 8.1. Voltage Regulator Electrical Specifications -40 to +85 C unless otherwise specified. Parameter Input Voltage Range1 Output Voltage (VDD)2 Output Current2 VBUS Detection Input Threshold Bias Current Dropout Voltage (VDO)3 Normal Mode (REGMOD = `0') Low Power Mode (REGMOD = `1') IDD = 1 mA IDD = 100 mA 1.0 1.8 90 60 1 100 Output Current = 1 to 100 mA Conditions Min 2.7 3.0 Typ Max 5.25 Units V V mA V A mV/mA 3.3 3.6 100 4.0 TBD TBD Notes: 1. Input range specified for regulation. When an external regulator is used, should be tied to VDD. 2. Output current is total regulator output, including any current required by the C8051F34x. 3. The minimum input voltage is 2.70 V or VDD + VDO (max load), whichever is greater. Rev. 0.5 69 C8051F340/1/2/3/4/5/6/7 VBUS From VBUS REGIN 5 V In VBUS Sense Voltage Regulator (REG0) 3 V Out To 3 V Power Net VDD Device Power Net Figure 8.1. REG0 Configuration: USB Bus-Powered From VBUS VBUS VBUS Sense From 5 V Power Net REGIN 5 V In Voltage Regulator (REG0) 3 V Out To 3 V Power Net VDD Device Power Net Figure 8.2. REG0 Configuration: USB Self-Powered 70 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 From VBUS VBUS VBUS Sense REGIN 5 V In Voltage Regulator (REG0) 3 V Out From 3 V Power Net VDD Device Power Net Figure 8.3. REG0 Configuration: USB Self-Powered, Regulator Disabled VBUS VBUS Sense From 5 V Power Net REGIN 5 V In Voltage Regulator (REG0) 3 V Out To 3 V Power Net VDD Device Power Net Figure 8.4. REG0 Configuration: No USB Connection Rev. 0.5 71 C8051F340/1/2/3/4/5/6/7 SFR Definition 8.1. REG0CN: Voltage Regulator Control R/W R R/W R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value SFR Address: REGDIS Bit7 VBSTAT Bit6 VBPOL Bit5 REGMOD Reserved Reserved Reserved Reserved 00000000 0xC9 REGDIS: Voltage Regulator Disable. 0: Voltage Regulator Enabled. 1: Voltage Regulator Disabled. Bit6: VBSTAT: VBUS Signal Status. 0: VBUS signal currently absent (device not attached to USB network). 1: VBUS signal currently present (device attached to USB network). Bit5: VBPOL: VBUS Interrupt Polarity Select. This bit selects the VBUS interrupt polarity. 0: VBUS interrupt active when VBUS is low. 1: VBUS interrupt active when VBUS is high. Bit4: REGMOD: Voltage Regulator Mode Select. This bit selects the Voltage Regulator mode. When REGMOD is set to `1', the voltage regulator operates in low power (suspend) mode. 0: USB0 Voltage Regulator in normal mode. 1: USB0 Voltage Regulator in low power mode. Bits3-0: Reserved. Read = 0000b. Must Write = 0000b. Bit7: 72 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 9. CIP-51 Microcontroller The MCU system controller core is the CIP-51 microcontroller. The CIP-51 is fully compatible with the MCS-51TM instruction set; standard 803x/805x assemblers and compilers can be used to develop software. The MCU family has a superset of all the peripherals included with a standard 8051. Included are four 16-bit counter/timers (see description in Section 21), an enhanced full-duplex UART (see description in Section 18), an Enhanced SPI (see description in Section 20), 256 bytes of internal RAM, 128 byte Special Function Register (SFR) address space (Section 9.2.6), and 25 Port I/O (see description in Section 15). The CIP-51 also includes on-chip debug hardware (see description in Section 23), and interfaces directly with the analog and digital subsystems providing a complete data acquisition or control-system solution in a single integrated circuit. The CIP-51 Microcontroller core implements the standard 8051 organization and peripherals as well as additional custom peripherals and functions to extend its capability (see Figure 9.1 for a block diagram). The CIP-51 includes the following features: - Fully Compatible with MCS-51 Instruction Set - 0 to 48 MHz Clock Frequency - 256 Bytes of Internal RAM - 25 Port I/O Extended Interrupt Handler Reset Input Power Management Modes On-chip Debug Logic Program and Data Memory Security DATA BUS D8 D8 D8 D8 D8 ACCUMULATOR B REGISTER STACK POINTER DATA BUS TMP1 TMP2 PSW ALU D8 D8 SRAM ADDRESS REGISTER D8 SRAM (256 X 8) D8 DATA BUS SFR_ADDRESS BUFFER D8 DATA POINTER D8 D8 SFR BUS INTERFACE SFR_CONTROL SFR_WRITE_DATA SFR_READ_DATA PC INCREMENTER DATA BUS PROGRAM COUNTER (PC) D8 MEM_ADDRESS MEM_CONTROL PRGM. ADDRESS REG. A16 MEMORY INTERFACE MEM_WRITE_DATA MEM_READ_DATA PIPELINE RESET CLOCK STOP IDLE POWER CONTROL REGISTER D8 D8 CONTROL LOGIC INTERRUPT INTERFACE SYSTEM_IRQs EMULATION_IRQ D8 Figure 9.1. CIP-51 Block Diagram Rev. 0.5 73 C8051F340/1/2/3/4/5/6/7 Performance The CIP-51 employs a pipelined architecture that greatly increases its instruction throughput over the standard 8051 architecture. In a standard 8051, all instructions except for MUL and DIV take 12 or 24 system clock cycles to execute, and usually have a maximum system clock of 12 MHz. By contrast, the CIP-51 core executes 70% of its instructions in one or two system clock cycles, with no instructions taking more than eight system clock cycles. With the CIP-51's maximum system clock at 25 MHz, it has a peak throughput of 25 MIPS. The CIP-51 has a total of 109 instructions. The table below shows the total number of instructions that for execution time. Clocks to Execute Number of Instructions 1 26 2 50 2/4 5 3 10 3/5 7 4 5 5 2 4/6 1 6 2 8 1 Programming and Debugging Support In-system programming of the Flash program memory and communication with on-chip debug support logic is accomplished via the Silicon Labs 2-Wire Development Interface (C2). Note that the re-programmable Flash can also be read and changed a single byte at a time by the application software using the MOVC and MOVX instructions. This feature allows program memory to be used for non-volatile data storage as well as updating program code under software control. The on-chip Silicon Labs 2-Wire (C2) Development Interface allows non-intrusive (uses no on-chip resources), full speed, in-circuit debugging using the production MCU installed in the final application. This debug logic supports inspection and modification of memory and registers, setting breakpoints, single stepping, run and halt commands. All analog and digital peripherals are fully functional while debugging using C2. The two C2 interface pins can be shared with user functions, allowing in-system debugging without occupying package pins. C2 details can be found in Section "23. C2 Interface" on page 279. The CIP-51 is supported by development tools from Silicon Labs and third party vendors. Silicon Labs provides an integrated development environment (IDE) including editor, debugger, and programmer. The IDE's debugger and programmer interface to the CIP-51 via the C2 interface to provide fast and efficient in-system device programming and debugging. An 8051 assembler, linker and evaluation `C' compiler are included in the Development Kit. Many third party macro assemblers and C compilers are also available, which can be used directly with the IDE. 9.1. Instruction Set The instruction set of the CIP-51 System Controller is fully compatible with the standard MCS-51TM instruction set. Standard 8051 development tools can be used to develop software for the CIP-51. All CIP-51 instructions are the binary and functional equivalent of their MCS-51TM counterparts, including opcodes, addressing modes and effect on PSW flags. However, instruction timing is different than that of the standard 8051. 9.1.1. Instruction and CPU Timing In many 8051 implementations, a distinction is made between machine cycles and clock cycles, with machine cycles varying from 2 to 12 clock cycles in length. However, the CIP-51 implementation is based solely on clock cycle timing. All instruction timings are specified in terms of clock cycles. Due to the pipelined architecture of the CIP-51, most instructions execute in the same number of clock cycles as there are program bytes in the instruction. Conditional branch instructions take one less clock cycle to complete when the branch is not taken as opposed to when the branch is taken. Table 9.1 is the 74 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 CIP-51 Instruction Set Summary, which includes the mnemonic, number of bytes, and number of clock cycles for each instruction. 9.1.2. MOVX Instruction and Program Memory The MOVX instruction is typically used to access external data memory (Note: the C8051F340/1/2/3/4/5/6/ 7 does not support off-chip data or program memory). In the CIP-51, the MOVX write instruction is used to accesses external RAM (XRAM) and the on-chip program memory space implemented as re-programmable Flash memory. The Flash access feature provides a mechanism for the CIP-51 to update program code and use the program memory space for non-volatile data storage. Refer to Section "12. Flash Memory" on page 109 for further details. Table 9.1. CIP-51 Instruction Set Summary Mnemonic ADD A, Rn ADD A, direct ADD A, @Ri ADD A, #data ADDC A, Rn ADDC A, direct ADDC A, @Ri ADDC A, #data SUBB A, Rn SUBB A, direct SUBB A, @Ri SUBB A, #data INC A INC Rn INC direct INC @Ri DEC A DEC Rn DEC direct DEC @Ri INC DPTR MUL AB DIV AB DA A ANL A, Rn ANL A, direct ANL A, @Ri ANL A, #data ANL direct, A ANL direct, #data ORL A, Rn Description Arithmetic Operations Add register to A Add direct byte to A Add indirect RAM to A Add immediate to A Add register to A with carry Add direct byte to A with carry Add indirect RAM to A with carry Add immediate to A with carry Subtract register from A with borrow Subtract direct byte from A with borrow Subtract indirect RAM from A with borrow Subtract immediate from A with borrow Increment A Increment register Increment direct byte Increment indirect RAM Decrement A Decrement register Decrement direct byte Decrement indirect RAM Increment Data Pointer Multiply A and B Divide A by B Decimal adjust A Logical Operations AND Register to A AND direct byte to A AND indirect RAM to A AND immediate to A AND A to direct byte AND immediate to direct byte OR Register to A Bytes 1 2 1 2 1 2 1 2 1 2 1 2 1 1 2 1 1 1 2 1 1 1 1 1 1 2 1 2 2 3 1 Clock Cycles 1 2 2 2 1 2 2 2 1 2 2 2 1 1 2 2 1 1 2 2 1 4 8 1 1 2 2 2 2 3 1 Rev. 0.5 75 C8051F340/1/2/3/4/5/6/7 Table 9.1. CIP-51 Instruction Set Summary (Continued) Mnemonic ORL A, direct ORL A, @Ri ORL A, #data ORL direct, A ORL direct, #data XRL A, Rn XRL A, direct XRL A, @Ri XRL A, #data XRL direct, A XRL direct, #data CLR A CPL A RL A RLC A RR A RRC A SWAP A MOV A, Rn MOV A, direct MOV A, @Ri MOV A, #data MOV Rn, A MOV Rn, direct MOV Rn, #data MOV direct, A MOV direct, Rn MOV direct, direct MOV direct, @Ri MOV direct, #data MOV @Ri, A MOV @Ri, direct MOV @Ri, #data MOV DPTR, #data16 MOVC A, @A+DPTR MOVC A, @A+PC MOVX A, @Ri MOVX @Ri, A MOVX A, @DPTR MOVX @DPTR, A PUSH direct POP direct XCH A, Rn XCH A, direct Description OR direct byte to A OR indirect RAM to A OR immediate to A OR A to direct byte OR immediate to direct byte Exclusive-OR Register to A Exclusive-OR direct byte to A Exclusive-OR indirect RAM to A Exclusive-OR immediate to A Exclusive-OR A to direct byte Exclusive-OR immediate to direct byte Clear A Complement A Rotate A left Rotate A left through Carry Rotate A right Rotate A right through Carry Swap nibbles of A Data Transfer Move Register to A Move direct byte to A Move indirect RAM to A Move immediate to A Move A to Register Move direct byte to Register Move immediate to Register Move A to direct byte Move Register to direct byte Move direct byte to direct byte Move indirect RAM to direct byte Move immediate to direct byte Move A to indirect RAM Move direct byte to indirect RAM Move immediate to indirect RAM Load DPTR with 16-bit constant Move code byte relative DPTR to A Move code byte relative PC to A Move external data (8-bit address) to A Move A to external data (8-bit address) Move external data (16-bit address) to A Move A to external data (16-bit address) Push direct byte onto stack Pop direct byte from stack Exchange Register with A Exchange direct byte with A Bytes 2 1 2 2 3 1 2 1 2 2 3 1 1 1 1 1 1 1 1 2 1 2 1 2 2 2 2 3 2 3 1 2 2 3 1 1 1 1 1 1 2 2 1 2 Clock Cycles 2 2 2 2 3 1 2 2 2 2 3 1 1 1 1 1 1 1 1 2 2 2 1 2 2 2 2 3 2 3 2 2 2 3 3 3 3 3 3 3 2 2 1 2 76 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 9.1. CIP-51 Instruction Set Summary (Continued) Mnemonic XCH A, @Ri XCHD A, @Ri CLR C CLR bit SETB C SETB bit CPL C CPL bit ANL C, bit ANL C, /bit ORL C, bit ORL C, /bit MOV C, bit MOV bit, C JC rel JNC rel JB bit, rel JNB bit, rel JBC bit, rel ACALL addr11 LCALL addr16 RET RETI AJMP addr11 LJMP addr16 SJMP rel JMP @A+DPTR JZ rel JNZ rel CJNE A, direct, rel CJNE A, #data, rel CJNE Rn, #data, rel CJNE @Ri, #data, rel DJNZ Rn, rel DJNZ direct, rel NOP Description Exchange indirect RAM with A Exchange low nibble of indirect RAM with A Boolean Manipulation Clear Carry Clear direct bit Set Carry Set direct bit Complement Carry Complement direct bit AND direct bit to Carry AND complement of direct bit to Carry OR direct bit to carry OR complement of direct bit to Carry Move direct bit to Carry Move Carry to direct bit Jump if Carry is set Jump if Carry is not set Jump if direct bit is set Jump if direct bit is not set Jump if direct bit is set and clear bit Program Branching Absolute subroutine call Long subroutine call Return from subroutine Return from interrupt Absolute jump Long jump Short jump (relative address) Jump indirect relative to DPTR Jump if A equals zero Jump if A does not equal zero Compare direct byte to A and jump if not equal Compare immediate to A and jump if not equal Compare immediate to Register and jump if not equal Compare immediate to indirect and jump if not equal Decrement Register and jump if not zero Decrement direct byte and jump if not zero No operation Bytes 1 1 1 2 1 2 1 2 2 2 2 2 2 2 2 2 3 3 3 2 3 1 1 2 3 2 1 2 2 3 3 3 3 2 3 1 Clock Cycles 2 2 1 2 1 2 1 2 2 2 2 2 2 2 2/4 2/4 3/5 3/5 3/5 4 5 6 6 4 5 4 4 2/4 2/4 3/5 3/5 3/5 4/6 2/4 3/5 1 Rev. 0.5 77 C8051F340/1/2/3/4/5/6/7 Notes on Registers, Operands and Addressing Modes: Rn - Register R0-R7 of the currently selected register bank. @Ri - Data RAM location addressed indirectly through R0 or R1. rel - 8-bit, signed (two's complement) offset relative to the first byte of the following instruction. Used by SJMP and all conditional jumps. direct - 8-bit internal data location's address. This could be a direct-access Data RAM location (0x00-0x7F) or an SFR (0x80-0xFF). #data - 8-bit constant #data16 - 16-bit constant bit - Direct-accessed bit in Data RAM or SFR addr11 - 11-bit destination address used by ACALL and AJMP. The destination must be within the same 2K-byte page of program memory as the first byte of the following instruction. addr16 - 16-bit destination address used by LCALL and LJMP. The destination may be anywhere within the 8K-byte program memory space. There is one unused opcode (0xA5) that performs the same function as NOP. All mnemonics copyrighted (c) Intel Corporation 1980. 78 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 9.2. Memory Organization The memory organization of the CIP-51 System Controller is similar to that of a standard 8051. There are two separate memory spaces: program memory and data memory. Program and data memory share the same address space but are accessed via different instruction types. The CIP-51 memory organization is shown in Figure 9.2. PROGRAM/DATA MEMORY (FLASH) 0xFFFF 0xFC00 0xFBFF 0xFF RESERVED 0x80 0x7F DATA MEMORY (RAM) INTERNAL DATA ADDRESS SPACE Upper 128 RAM (Indirect Addressing Only) (Direct and Indirect Addressing) Special Function Register's (Direct Addressing Only) FLASH (In-System Programmable in 512 Byte Sectors) 0x30 0x2F 0x20 0x1F 0x00 Bit Addressable General Purpose Registers Lower 128 RAM (Direct and Indirect Addressing) EXTERNAL DATA ADDRESS SPACE 0x0000 0xFFFF Off-Chip XRAM (Available only on devices with EMIF) 0x1000 0x0FFF XRAM - 4096 Bytes (Accessable using MOVX instruction) USB FIFOs 1024 Bytes 0x07FF 0x0400 0x0000 Figure 9.2. Memory Map 9.2.1. Program Memory The CIP-51 core has a 64k-byte program memory space. The C8051F340/1/2/3/4/5/6/7 implements 64k or 32k bytes of this program memory space as in-system, re-programmable Flash memory. Note that on the C8051F340/2/4/6 (64k version), addresses above 0xFBFF are reserved. Program memory is normally assumed to be read-only. However, the CIP-51 can write to program memory by setting the Program Store Write Enable bit (PSCTL.0) and using the MOVX instruction. This feature provides a mechanism for the CIP-51 to update program code and use the program memory space for non-volatile data storage. Refer to Section "12. Flash Memory" on page 109 for further details. Rev. 0.5 79 C8051F340/1/2/3/4/5/6/7 9.2.2. Data Memory The CIP-51 includes 256 of internal RAM mapped into the data memory space from 0x00 through 0xFF. The lower 128 bytes of data memory are used for general purpose registers and scratch pad memory. Either direct or indirect addressing may be used to access the lower 128 bytes of data memory. Locations 0x00 through 0x1F are addressable as four banks of general purpose registers, each bank consisting of eight byte-wide registers. The next 16 bytes, locations 0x20 through 0x2F, may either be addressed as bytes or as 128 bit locations accessible with the direct addressing mode. The upper 128 bytes of data memory are accessible only by indirect addressing. This region occupies the same address space as the Special Function Registers (SFR) but is physically separate from the SFR space. The addressing mode used by an instruction when accessing locations above 0x7F determines whether the CPU accesses the upper 128 bytes of data memory space or the SFRs. Instructions that use direct addressing will access the SFR space. Instructions using indirect addressing above 0x7F access the upper 128 bytes of data memory. Figure 9.2 illustrates the data memory organization of the CIP-51. 9.2.3. General Purpose Registers The lower 32 bytes of data memory, locations 0x00 through 0x1F, may be addressed as four banks of general-purpose registers. Each bank consists of eight byte-wide registers designated R0 through R7. Only one of these banks may be enabled at a time. Two bits in the program status word, RS0 (PSW.3) and RS1 (PSW.4), select the active register bank (see description of the PSW in SFR Definition 9.4). This allows fast context switching when entering subroutines and interrupt service routines. Indirect addressing modes use registers R0 and R1 as index registers. 9.2.4. Bit Addressable Locations In addition to direct access to data memory organized as bytes, the sixteen data memory locations at 0x20 through 0x2F are also accessible as 128 individually addressable bits. Each bit has a bit address from 0x00 to 0x7F. Bit 0 of the byte at 0x20 has bit address 0x00 while bit7 of the byte at 0x20 has bit address 0x07. Bit 7 of the byte at 0x2F has bit address 0x7F. A bit access is distinguished from a full byte access by the type of instruction used (bit source or destination operands as opposed to a byte source or destination). The MCS-51TM assembly language allows an alternate notation for bit addressing of the form XX.B where XX is the byte address and B is the bit position within the byte. For example, the instruction: MOV C, 22h.3 moves the Boolean value at 0x13 (bit 3 of the byte at location 0x22) into the Carry flag. 9.2.5. Stack A programmer's stack can be located anywhere in the 256-byte data memory. The stack area is designated using the Stack Pointer (SP, 0x81) SFR. The SP will point to the last location used. The next value pushed on the stack is placed at SP+1 and then SP is incremented. A reset initializes the stack pointer to location 0x07. Therefore, the first value pushed on the stack is placed at location 0x08, which is also the first register (R0) of register bank 1. Thus, if more than one register bank is to be used, the SP should be initialized to a location in the data memory not being used for data storage. The stack depth can extend up to 256 bytes. 80 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 9.2.6. Special Function Registers The direct-access data memory locations from 0x80 to 0xFF constitute the special function registers (SFRs). The SFRs provide control and data exchange with the CIP-51's resources and peripherals. The CIP-51 duplicates the SFRs found in a typical 8051 implementation as well as implementing additional SFRs used to configure and access the sub-systems unique to the MCU. This allows the addition of new functionality while retaining compatibility with the MCS-51TM instruction set. Table 9.2 lists the SFRs implemented in the CIP-51 System Controller. The SFR registers are accessed anytime the direct addressing mode is used to access memory locations from 0x80 to 0xFF. SFRs with addresses ending in 0x0 or 0x8 (e.g. P0, TCON, SCON0, IE, etc.) are bit-addressable as well as byte-addressable. All other SFRs are byte-addressable only. Unoccupied addresses in the SFR space are reserved for future use. Accessing these areas will have an indeterminate effect and should be avoided. Refer to the corresponding pages of the datasheet, as indicated in Table 9.3, for a detailed description of each register. Table 9.2. Special Function Register (SFR) Memory Map F8 F0 E8 E0 D8 D0 C8 C0 B8 B0 A8 A0 98 90 88 80 SPI0CN PCA0L PCA0H PCA0CPL0 PCA0CPH0 PCA0CPL4 PCA0CPH4 B P0MDIN P1MDIN P2MDIN P3MDIN P4MDIN EIP1 ADC0CN PCA0CPL1 PCA0CPH1 PCA0CPL2 PCA0CPH2 PCA0CPL3 PCA0CPH3 ACC XBR0 XBR1 XBR2 IT01CF SMOD1 EIE1 PCA0CN PCA0MD PCA0CPM0 PCA0CPM1 PCA0CPM2 PCA0CPM3 PCA0CPM4 PSW REF0CN SCON1 SBUF1 P0SKIP P1SKIP P2SKIP TMR2CN REG0CN TMR2RLL TMR2RLH TMR2L TMR2H SMB0CN SMB0CF SMB0DAT ADC0GTL ADC0GTH ADC0LTL ADC0LTH IP CLKMUL AMX0N AMX0P ADC0CF ADC0L ADC0H P3 OSCXCN OSCICN OSCICL SBRLL1 SBRLH1 FLSCL IE CLKSEL EMI0CN SBCON1 P4MDOUT P2 SPI0CFG SPI0CKR SPI0DAT P0MDOUT P1MDOUT P2MDOUT SCON0 SBUF0 CPT1CN CPT0CN CPT1MD CPT0MD CPT1MX P1 TMR3CN TMR3RLL TMR3RLH TMR3L TMR3H USB0ADR TCON TMOD TL0 TL1 TH0 TH1 CKCON P0 SP DPL DPH EMI0TC EMI0CF OSCLCN 0(8) 1(9) 2(A) 3(B) 4(C) 5(D) 6(E) (bit addressable) VDM0CN EIP2 RSTSRC EIE2 P3SKIP USB0XCN P4 FLKEY PFE0CN P3MDOUT CPT0MX USB0DAT PSCTL PCON 7(F) Rev. 0.5 81 C8051F340/1/2/3/4/5/6/7 Table 9.3. Special Function Registers SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address Description ACC 0xE0 Accumulator ADC0CF 0xBC ADC0 Configuration ADC0CN 0xE8 ADC0 Control ADC0GTH 0xC4 ADC0 Greater-Than Compare High ADC0GTL 0xC3 ADC0 Greater-Than Compare Low ADC0H 0xBE ADC0 High ADC0L 0xBD ADC0 Low ADC0LTH 0xC6 ADC0 Less-Than Compare Word High ADC0LTL 0xC5 ADC0 Less-Than Compare Word Low AMX0N 0xBA AMUX0 Negative Channel Select AMX0P 0xBB AMUX0 Positive Channel Select B 0xF0 B Register CKCON 0x8E Clock Control CLKMUL 0xB9 Clock Multiplier CLKSEL 0xA9 Clock Select CPT0CN 0x9B Comparator0 Control CPT0MD 0x9D Comparator0 Mode Selection CPT0MX 0x9F Comparator0 MUX Selection CPT1CN 0x9A Comparator1 Control CPT1MD 0x9C Comparator1 Mode Selection CPT1MX 0x9E Comparator1 MUX Selection DPH 0x83 Data Pointer High DPL 0x82 Data Pointer Low EIE1 0xE6 Extended Interrupt Enable 1 EIE2 0xE7 Extended Interrupt Enable 2 EIP1 0xF6 Extended Interrupt Priority 1 EIP2 0xF7 Extended Interrupt Priority 2 EMI0CN 0xAA External Memory Interface Control EMI0CF 0x85 External Memory Interface Configuration EMI0TC 0x84 External Memory Interface Timing FLKEY 0xB7 Flash Lock and Key FLSCL 0xB6 Flash Scale IE 0xA8 Interrupt Enable IP 0xB8 Interrupt Priority IT01CF 0xE4 INT0/INT1 Configuration OSCICL 0xB3 Internal Oscillator Calibration OSCICN 0xB2 Internal Oscillator Control OSCLCN 0x86 Internal Low-Frequency Oscillator Control OSCXCN 0xB1 External Oscillator Control P0 0x80 Port 0 Latch P0MDIN 0xF1 Port 0 Input Mode Configuration P0MDOUT 0xA4 Port 0 Output Mode Configuration P0SKIP 0xD4 Port 0 Skip P1 0x90 Port 1 Latch Page 86 50 51 52 52 50 50 53 53 49 48 87 249 142 144 62 64 63 65 67 66 85 85 92 94 93 94 120 121 126 114 115 90 91 95 137 136 138 141 154 154 155 155 156 82 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 9.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address Description P1MDIN 0xF2 Port 1 Input Mode Configuration P1MDOUT 0xA5 Port 1 Output Mode Configuration P1SKIP 0xD5 Port 1 Skip P2 0xA0 Port 2 Latch P2MDIN 0xF3 Port 2 Input Mode Configuration P2MDOUT 0xA6 Port 2 Output Mode Configuration P2SKIP 0xD6 Port 2 Skip P3 0xB0 Port 3 Latch P3MDIN 0xF4 Port 3 Input Mode Configuration P3MDOUT 0xA7 Port 3 Output Mode Configuration P3SKIP 0xDF Port 3Skip P4 0xC7 Port 4 Latch P4MDIN 0xF5 Port 4 Input Mode Configuration P4MDOUT 0xAE Port 4 Output Mode Configuration PCA0CN 0xD8 PCA Control PCA0CPH0 0xFC PCA Capture 0 High PCA0CPH1 0xEA PCA Capture 1 High PCA0CPH2 0xEC PCA Capture 2 High PCA0CPH3 0xEE PCA Capture 3High PCA0CPH4 0xFE PCA Capture 4 High PCA0CPL0 0xFB PCA Capture 0 Low PCA0CPL1 0xE9 PCA Capture 1 Low PCA0CPL2 0xEB PCA Capture 2 Low PCA0CPL3 0xED PCA Capture 3 Low PCA0CPL4 0xFD PCA Capture 4 Low PCA0CPM0 0xDA PCA Module 0 Mode Register PCA0CPM1 0xDB PCA Module 1 Mode Register PCA0CPM2 0xDC PCA Module 2 Mode Register PCA0CPM3 0xDD PCA Module 3 Mode Register PCA0CPM4 0xDE PCA Module 4 Mode Register PCA0H 0xFA PCA Counter High PCA0L 0xF9 PCA Counter Low PCA0MD 0xD9 PCA Mode PCON 0x87 Power Control PFE0CN 0xAF Prefetch Engine Control PSCTL 0x8F Program Store R/W Control PSW 0xD0 Program Status Word REF0CN 0xD1 Voltage Reference Control REG0CN 0xC9 Voltage Regulator Control RSTSRC 0xEF Reset Source Configuration/Status SBCON1 0xAC UART1 Baud Rate Generator Control SBRLH1 0xB5 UART1 Baud Rate Generator High SBRLL1 0xB4 UART1 Baud Rate Generator Low SBUF1 0xD3 UART1 Data Buffer SCON1 0xD2 UART1 Control Page 156 156 157 157 157 158 158 159 159 159 160 160 161 161 274 278 278 278 278 278 277 277 277 277 277 276 276 276 276 276 277 277 275 97 99 114 86 58 72 106 226 227 227 226 224 Rev. 0.5 83 C8051F340/1/2/3/4/5/6/7 Table 9.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved. Register Address Description SBUF0 0x99 UART0 Data Buffer SCON0 0x98 UART0 Control SMB0CF 0xC1 SMBus Configuration SMB0CN 0xC0 SMBus Control SMB0DAT 0xC2 SMBus Data SMOD1 0xE5 UART1 Mode SP 0x81 Stack Pointer SPI0CFG 0xA1 SPI Configuration SPI0CKR 0xA2 SPI Clock Rate Control SPI0CN 0xF8 SPI Control SPI0DAT 0xA3 SPI Data TCON 0x88 Timer/Counter Control TH0 0x8C Timer/Counter 0 High TH1 0x8D Timer/Counter 1 High TL0 0x8A Timer/Counter 0 Low TL1 0x8B Timer/Counter 1 Low TMOD 0x89 Timer/Counter Mode TMR2CN 0xC8 Timer/Counter 2 Control TMR2H 0xCD Timer/Counter 2 High TMR2L 0xCC Timer/Counter 2 Low TMR2RLH 0xCB Timer/Counter 2 Reload High TMR2RLL 0xCA Timer/Counter 2 Reload Low TMR3CN 0x91 Timer/Counter 3Control TMR3H 0x95 Timer/Counter 3 High TMR3L 0x94 Timer/Counter 3Low TMR3RLH 0x93 Timer/Counter 3 Reload High TMR3RLL 0x92 Timer/Counter 3 Reload Low VDD Monitor Control VDM0CN 0xFF USB0ADR 0x96 USB0 Indirect Address Register USB0DAT 0x97 USB0 Data Register USB0XCN 0xD7 USB0 Transceiver Control XBR0 0xE1 Port I/O Crossbar Control 0 XBR1 0xE2 Port I/O Crossbar Control 1 XBR2 0xE3 Port I/O Crossbar Control 2 All Other Addresses Reserved Page 217 216 200 202 204 225 85 236 238 237 238 247 250 250 250 250 248 255 256 256 256 256 261 262 262 262 262 103 167 168 165 152 153 153 84 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 9.2.7. Register Descriptions Following are descriptions of SFRs related to the operation of the CIP-51 System Controller. Reserved bits should not be set to logic l. Future product versions may use these bits to implement new features in which case the reset value of the bit will be logic 0, selecting the feature's default state. Detailed descriptions of the remaining SFRs are included in the sections of the datasheet associated with their corresponding system function. SFR Definition 9.1. DPL: Data Pointer Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x82 Bits7-0: DPL: Data Pointer Low. The DPL register is the low byte of the 16-bit DPTR. DPTR is used to access indirectly addressed memory. SFR Definition 9.2. DPH: Data Pointer High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x83 Bits7-0: DPH: Data Pointer High. The DPH register is the high byte of the 16-bit DPTR. DPTR is used to access indirectly addressed memory. SFR Definition 9.3. SP: Stack Pointer R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000111 SFR Address: 0x81 Bits7-0: SP: Stack Pointer. The Stack Pointer holds the location of the top of the stack. The stack pointer is incremented before every PUSH operation. The SP register defaults to 0x07 after reset. Rev. 0.5 85 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.4. PSW: Program Status Word R/W R/W R/W R/W R/W R/W R/W R Reset Value CY Bit7 AC Bit6 F0 Bit5 RS1 Bit4 RS0 Bit3 OV Bit2 F1 Bit1 PARITY Bit0 (bit addressable) 00000000 SFR Address: 0xD0 CY: Carry Flag. This bit is set when the last arithmetic operation resulted in a carry (addition) or a borrow (subtraction). It is cleared to logic 0 by all other arithmetic operations. Bit6: AC: Auxiliary Carry Flag This bit is set when the last arithmetic operation resulted in a carry into (addition) or a borrow from (subtraction) the high order nibble. It is cleared to logic 0 by all other arithmetic operations. Bit5: F0: User Flag 0. This is a bit-addressable, general purpose flag for use under software control. Bits4-3: RS1-RS0: Register Bank Select. These bits select which register bank is used during register accesses. Bit7: RS1 0 0 1 1 Bit2: RS0 0 1 0 1 Register Bank 0 1 2 3 Address 0x00 - 0x07 0x08 - 0x0F 0x10 - 0x17 0x18 - 0x1F Bit1: Bit0: OV: Overflow Flag. This bit is set to 1 under the following circumstances: * An ADD, ADDC, or SUBB instruction causes a sign-change overflow. * A MUL instruction results in an overflow (result is greater than 255). * A DIV instruction causes a divide-by-zero condition. The OV bit is cleared to 0 by the ADD, ADDC, SUBB, MUL, and DIV instructions in all other cases. F1: User Flag 1. This is a bit-addressable, general purpose flag for use under software control. PARITY: Parity Flag. This bit is set to logic 1 if the sum of the eight bits in the accumulator is odd and cleared if the sum is even. SFR Definition 9.5. ACC: Accumulator R/W R/W R/W R/W R/W R/W R/W R/W Reset Value ACC.7 Bit7 ACC.6 Bit6 ACC.5 Bit5 ACC.4 Bit4 ACC.3 Bit3 ACC.2 Bit2 ACC.1 Bit1 ACC.0 Bit0 00000000 SFR Address: (bit addressable) 0xE0 Bits7-0: ACC: Accumulator. This register is the accumulator for arithmetic operations. 86 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.6. B: B Register R/W R/W R/W R/W R/W R/W R/W R/W Reset Value B.7 Bit7 B.6 Bit6 B.5 Bit5 B.4 Bit4 B.3 Bit3 B.2 Bit2 B.1 Bit1 B.0 Bit0 (bit addressable) 00000000 SFR Address: 0xF0 Bits7-0: B: B Register. This register serves as a second accumulator for certain arithmetic operations. 9.3. Interrupt Handler The CIP-51 includes an extended interrupt system supporting multiple interrupt sources with two priority levels. The allocation of interrupt sources between on-chip peripherals and external inputs pins varies according to the specific version of the device. Each interrupt source has one or more associated interrupt-pending flag(s) located in an SFR. When a peripheral or external source meets a valid interrupt condition, the associated interrupt-pending flag is set to logic 1. If interrupts are enabled for the source, an interrupt request is generated when the interrupt-pending flag is set. As soon as execution of the current instruction is complete, the CPU generates an LCALL to a predetermined address to begin execution of an interrupt service routine (ISR). Each ISR must end with an RETI instruction, which returns program execution to the next instruction that would have been executed if the interrupt request had not occurred. If interrupts are not enabled, the interrupt-pending flag is ignored by the hardware and program execution continues as normal. (The interrupt-pending flag is set to logic 1 regardless of the interrupt's enable/disable state.) Each interrupt source can be individually enabled or disabled through the use of an associated interrupt enable bit in an SFR (IE-EIE2). However, interrupts must first be globally enabled by setting the EA bit (IE.7) to logic 1 before the individual interrupt enables are recognized. Setting the EA bit to logic 0 disables all interrupt sources regardless of the individual interrupt-enable settings. Some interrupt-pending flags are automatically cleared by the hardware when the CPU vectors to the ISR. However, most are not cleared by the hardware and must be cleared by software before returning from the ISR. If an interrupt-pending flag remains set after the CPU completes the return-from-interrupt (RETI) instruction, a new interrupt request will be generated immediately and the CPU will re-enter the ISR after the completion of the next instruction. 9.3.1. MCU Interrupt Sources and Vectors The MCU supports multiple interrupt sources. Software can simulate an interrupt by setting any interrupt-pending flag to logic 1. If interrupts are enabled for the flag, an interrupt request will be generated and the CPU will vector to the ISR address associated with the interrupt-pending flag. MCU interrupt sources, associated vector addresses, priority order and control bits are summarized in Table 9.4 on page 89. Refer to the datasheet section associated with a particular on-chip peripheral for information regarding valid interrupt conditions for the peripheral and the behavior of its interrupt-pending flag(s). 9.3.2. External Interrupts The /INT0 and /INT1 external interrupt sources are configurable as active high or low, edge or level sensitive. The IN0PL (/INT0 Polarity) and IN1PL (/INT1 Polarity) bits in the IT01CF register select active high or active low; the IT0 and IT1 bits in TCON (Section "21.1. Timer 0 and Timer 1" on page 243) select level or edge sensitive. The following table lists the possible configurations. Rev. 0.5 87 C8051F340/1/2/3/4/5/6/7 IT0 1 1 0 0 IN0PL 0 1 0 1 /INT0 Interrupt Active low, edge sensitive Active high, edge sensitive Active low, level sensitive Active high, level sensitive IT1 1 1 0 0 IN1PL 0 1 0 1 /INT1 Interrupt Active low, edge sensitive Active high, edge sensitive Active low, level sensitive Active high, level sensitive /INT0 and /INT1 are assigned to Port pins as defined in the IT01CF register (see SFR Definition 9.13). Note that /INT0 and /INT0 Port pin assignments are independent of any Crossbar assignments. /INT0 and /INT1 will monitor their assigned Port pins without disturbing the peripheral that was assigned the Port pin via the Crossbar. To assign a Port pin only to /INT0 and/or /INT1, configure the Crossbar to skip the selected pin(s). This is accomplished by setting the associated bit in register XBR0 (see Section "15.1. Priority Crossbar Decoder" on page 149 for complete details on configuring the Crossbar). IE0 (TCON.1) and IE1 (TCON.3) serve as the interrupt-pending flags for the /INT0 and /INT1 external interrupts, respectively. If an /INT0 or /INT1 external interrupt is configured as edge-sensitive, the corresponding interrupt-pending flag is automatically cleared by the hardware when the CPU vectors to the ISR. When configured as level sensitive, the interrupt-pending flag remains logic 1 while the input is active as defined by the corresponding polarity bit (IN0PL or IN1PL); the flag remains logic 0 while the input is inactive. The external interrupt source must hold the input active until the interrupt request is recognized. It must then deactivate the interrupt request before execution of the ISR completes or another interrupt request will be generated. 9.3.3. Interrupt Priorities Each interrupt source can be individually programmed to one of two priority levels: low or high. A low priority interrupt service routine can be preempted by a high priority interrupt. A high priority interrupt cannot be preempted. Each interrupt has an associated interrupt priority bit in an SFR (IP or EIP2) used to configure its priority level. Low priority is the default. If two interrupts are recognized simultaneously, the interrupt with the higher priority is serviced first. If both interrupts have the same priority level, a fixed priority order is used to arbitrate, given in Table 9.4. 9.3.4. Interrupt Latency Interrupt response time depends on the state of the CPU when the interrupt occurs. Pending interrupts are sampled and priority decoded each system clock cycle. Therefore, the fastest possible response time is 6 system clock cycles: 1 clock cycle to detect the interrupt and 5 clock cycles to complete the LCALL to the ISR. If an interrupt is pending when a RETI is executed, a single instruction is executed before an LCALL is made to service the pending interrupt. Therefore, the maximum response time for an interrupt (when no other interrupt is currently being serviced or the new interrupt is of greater priority) occurs when the CPU is performing an RETI instruction followed by a DIV as the next instruction. In this case, the response time is 20 system clock cycles: 1 clock cycle to detect the interrupt, 6 clock cycles to execute the RETI, 8 clock cycles to complete the DIV instruction and 5 clock cycles to execute the LCALL to the ISR. If the CPU is executing an ISR for an interrupt with equal or higher priority, the new interrupt will not be serviced until the current ISR completes, including the RETI and following instruction. Note that the CPU is stalled during Flash write/erase operations and USB FIFO MOVX accesses (see Section "13.2. Accessing USB FIFO Space" on page 118). Interrupt service latency will be increased for interrupts occurring while the CPU is stalled. The latency for these situations will be determined by the standard interrupt service procedure (as described above) and the amount of time the CPU is stalled. 88 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 9.4. Interrupt Summary Bit addressable? Cleared by HW? Interrupt Source Interrupt Vector Priority Pending Flag Order Enable Flag Priority Control Reset External Interrupt 0 (/ INT0) Timer 0 Overflow External Interrupt 1 (/ INT1) Timer 1 Overflow UART0 Timer 2 Overflow 0x0000 0x0003 0x000B 0x0013 0x001B 0x0023 0x002B Top 0 1 2 3 4 5 None IE0 (TCON.1) TF0 (TCON.5) IE1 (TCON.3) TF1 (TCON.7) RI0 (SCON0.0) TI0 (SCON0.1) TF2H (TMR2CN.7) TF2L (TMR2CN.6) SPIF (SPI0CN.7) WCOL (SPI0CN.6) MODF (SPI0CN.5) RXOVRN (SPI0CN.4) SI (SMB0CN.0) Special AD0WINT (ADC0CN.3) AD0INT (ADC0CN.5) CF (PCA0CN.7) CCFn (PCA0CN.n) CP0FIF (CPT0CN.4) CP0RIF (CPT0CN.5) CP1FIF (CPT1CN.4) CP1RIF (CPT1CN.5) TF3H (TMR3CN.7) TF3L (TMR3CN.6) N/A RI1 (SCON1.0) TI1 (SCON1.1) N/A Y Y Y Y Y Y N/A Y Y Y Y N N Always Enabled Always Highest EX0 (IE.0) PX0 (IP.0) ET0 (IE.1) PT0 (IP.1) EX1 (IE.2) PX1 (IP.2) ET1 (IE.3) PT1 (IP.3) ES0 (IE.4) PS0 (IP.4) ET2 (IE.5) PT2 (IP.5) ESPI0 (IE.6) PSPI0 (IP.6) PSMB0 (EIP1.0) PUSB0 (EIP1.1) PWADC0 (EIP1.2) PADC0 (EIP1.3) PPCA0 (EIP1.4) PCP0 (EIP1.5) PCP1 (EIP1.6) PT3 (EIP1.7) PVBUS (EIP2.0) PS1 (EIP2.1) SPI0 0x0033 6 Y N SMB0 USB0 ADC0 Window Compare ADC0 Conversion Complete Programmable Counter Array Comparator0 Comparator1 Timer 3 Overflow VBUS Level UART1 0x003B 0x0043 0x004B 0x0053 0x005B 0x0063 0x006B 0x0073 0x007B 0x0083 7 8 9 10 11 12 13 14 15 16 Y N Y Y Y N N N N/A N ESMB0 (EIE1.0) EUSB0 N (EIE1.1) EWADC0 N (EIE1.2) EADC0 N (EIE1.3) EPCA0 N (EIE1.4) ECP0 N (EIE1.5) ECP1 N (EIE1.6) ET3 N (EIE1.7) EVBUS N/A (EIE2.0) ES1 N (EIE2.1) N 9.3.5. Interrupt Register Descriptions The SFRs used to enable the interrupt sources and set their priority level are described below. Refer to the datasheet section associated with a particular on-chip peripheral for information regarding valid interrupt conditions for the peripheral and the behavior of its interrupt-pending flag(s). Rev. 0.5 89 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.7. IE: Interrupt Enable R/W R/W R/W R/W R/W R/W R/W R/W Reset Value EA Bit7 ESPI0 Bit6 ET2 Bit5 ES0 Bit4 ET1 Bit3 EX1 Bit2 ET0 Bit1 EX0 Bit0 (bit addressable) 00000000 SFR Address: 0xA8 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: EA: Enable All Interrupts. This bit globally enables/disables all interrupts. It overrides the individual interrupt mask settings. 0: Disable all interrupt sources. 1: Enable each interrupt according to its individual mask setting. ESPI0: Enable Serial Peripheral Interface (SPI0) Interrupt. This bit sets the masking of the SPI0 interrupts. 0: Disable all SPI0 interrupts. 1: Enable interrupt requests generated by SPI0. ET2: Enable Timer 2 Interrupt. This bit sets the masking of the Timer 2 interrupt. 0: Disable Timer 2 interrupt. 1: Enable interrupt requests generated by the TF2L or TF2H flags. ES0: Enable UART0 Interrupt. This bit sets the masking of the UART0 interrupt. 0: Disable UART0 interrupt. 1: Enable UART0 interrupt. ET1: Enable Timer 1 Interrupt. This bit sets the masking of the Timer 1 interrupt. 0: Disable all Timer 1 interrupt. 1: Enable interrupt requests generated by the TF1 flag. EX1: Enable External Interrupt 1. This bit sets the masking of External Interrupt 1. 0: Disable external interrupt 1. 1: Enable interrupt requests generated by the /INT1 input. ET0: Enable Timer 0 Interrupt. This bit sets the masking of the Timer 0 interrupt. 0: Disable all Timer 0 interrupt. 1: Enable interrupt requests generated by the TF0 flag. EX0: Enable External Interrupt 0. This bit sets the masking of External Interrupt 0. 0: Disable external interrupt 0. 1: Enable interrupt requests generated by the /INT0 input. 90 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.8. IP: Interrupt Priority R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 PSPI0 Bit6 PT2 Bit5 PS0 Bit4 PT1 Bit3 PX1 Bit2 PT0 Bit1 PX0 Bit0 (bit addressable) 10000000 SFR Address: 0xB8 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: UNUSED. Read = 1, Write = don't care. PSPI0: Serial Peripheral Interface (SPI0) Interrupt Priority Control. This bit sets the priority of the SPI0 interrupt. 0: SPI0 interrupt set to low priority level. 1: SPI0 interrupt set to high priority level. PT2: Timer 2 Interrupt Priority Control. This bit sets the priority of the Timer 2 interrupt. 0: Timer 2 interrupt set to low priority level. 1: Timer 2 interrupts set to high priority level. PS0: UART0 Interrupt Priority Control. This bit sets the priority of the UART0 interrupt. 0: UART0 interrupt set to low priority level. 1: UART0 interrupts set to high priority level. PT1: Timer 1 Interrupt Priority Control. This bit sets the priority of the Timer 1 interrupt. 0: Timer 1 interrupt set to low priority level. 1: Timer 1 interrupts set to high priority level. PX1: External Interrupt 1 Priority Control. This bit sets the priority of the External Interrupt 1 interrupt. 0: External Interrupt 1 set to low priority level. 1: External Interrupt 1 set to high priority level. PT0: Timer 0 Interrupt Priority Control. This bit sets the priority of the Timer 0 interrupt. 0: Timer 0 interrupt set to low priority level. 1: Timer 0 interrupt set to high priority level. PX0: External Interrupt 0 Priority Control. This bit sets the priority of the External Interrupt 0 interrupt. 0: External Interrupt 0 set to low priority level. 1: External Interrupt 0 set to high priority level. Rev. 0.5 91 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.9. EIE1: Extended Interrupt Enable 1 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value ET3 Bit7 ECP1 Bit6 ECP0 Bit5 EPCA0 Bit4 EADC0 Bit3 EWADC0 Bit2 EUSB0 Bit1 ESMB0 Bit0 00000000 SFR Address: 0xE6 Bit7: ET3: Enable Timer 3 Interrupt. This bit sets the masking of the Timer 3 interrupt. 0: Disable Timer 3 interrupts. 1: Enable interrupt requests generated by the TF3L or TF3H flags. ECP1: Enable Comparator1 (CP1) Interrupt. This bit sets the masking of the CP1 interrupt. 0: Disable CP1 interrupts. 1: Enable interrupt requests generated by the CP1RIF or CP1FIF flags. ECP0: Enable Comparator0 (CP0) Interrupt. This bit sets the masking of the CP0 interrupt. 0: Disable CP0 interrupts. 1: Enable interrupt requests generated by the CP0RIF or CP0FIF flags. EPCA0: Enable Programmable Counter Array (PCA0) Interrupt. This bit sets the masking of the PCA0 interrupts. 0: Disable all PCA0 interrupts. 1: Enable interrupt requests generated by PCA0. EADC0: Enable ADC0 Conversion Complete Interrupt. This bit sets the masking of the ADC0 Conversion Complete interrupt. 0: Disable ADC0 Conversion Complete interrupt. 1: Enable interrupt requests generated by the AD0INT flag. EWADC0: Enable Window Comparison ADC0 Interrupt. This bit sets the masking of ADC0 Window Comparison interrupt. 0: Disable ADC0 Window Comparison interrupt. 1: Enable interrupt requests generated by ADC0 Window Compare flag (AD0WINT). EUSB0: Enable USB0 Interrupt. This bit sets the masking of the USB0 interrupt. 0: Disable all USB0 interrupts. 1: Enable interrupt requests generated by USB0. ESMB0: Enable SMBus (SMB0) Interrupt. This bit sets the masking of the SMB0 interrupt. 0: Disable all SMB0 interrupts. 1: Enable interrupt requests generated by SMB0. Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: 92 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.10. EIP1: Extended Interrupt Priority 1 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value PT3 Bit7 PCP1 Bit6 PCP0 Bit5 PPCA0 Bit4 PADC0 Bit3 PWADC0 Bit2 PUSB0 Bit1 PSMB0 Bit0 00000000 SFR Address: 0xF6 Bit7: PT3: Timer 3 Interrupt Priority Control. This bit sets the priority of the Timer 3 interrupt. 0: Timer 3 interrupts set to low priority level. 1: Timer 3 interrupts set to high priority level. PCP1: Comparator1 (CP1) Interrupt Priority Control. This bit sets the priority of the CP1 interrupt. 0: CP1 interrupt set to low priority level. 1: CP1 interrupt set to high priority level. PCP0: Comparator0 (CP0) Interrupt Priority Control. This bit sets the priority of the CP0 interrupt. 0: CP0 interrupt set to low priority level. 1: CP0 interrupt set to high priority level. PPCA0: Programmable Counter Array (PCA0) Interrupt Priority Control. This bit sets the priority of the PCA0 interrupt. 0: PCA0 interrupt set to low priority level. 1: PCA0 interrupt set to high priority level. PADC0 ADC0 Conversion Complete Interrupt Priority Control. This bit sets the priority of the ADC0 Conversion Complete interrupt. 0: ADC0 Conversion Complete interrupt set to low priority level. 1: ADC0 Conversion Complete interrupt set to high priority level. PWADC0: ADC0 Window Comparator Interrupt Priority Control. This bit sets the priority of the ADC0 Window interrupt. 0: ADC0 Window interrupt set to low priority level. 1: ADC0 Window interrupt set to high priority level. PUSB0: USB0 Interrupt Priority Control. This bit sets the priority of the USB0 interrupt. 0: USB0 interrupt set to low priority level. 1: USB0 interrupt set to high priority level. PSMB0: SMBus (SMB0) Interrupt Priority Control. This bit sets the priority of the SMB0 interrupt. 0: SMB0 interrupt set to low priority level. 1: SMB0 interrupt set to high priority level. Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Rev. 0.5 93 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.11. EIE2: Extended Interrupt Enable 2 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 ES1 Bit1 EVBUS Bit0 00000000 SFR Address: 0xE7 Bits7-2: UNUSED. Read = 000000b. Write = don't care. Bit1: ES1: Enable UART1 Interrupt. This bit sets the masking of the UART1 interrupt. 0: Disable UART1 interrupt. 1: Enable UART1 interrupt. Bit0: EVBUS: Enable VBUS Level Interrupt. This bit sets the masking of the VBUS interrupt. 0: Disable all VBUS interrupts. 1: Enable interrupt requests generated by VBUS level sense. SFR Definition 9.12. EIP2: Extended Interrupt Priority 2 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 PS1 Bit1 PVBUS Bit0 00000000 SFR Address: 0xF7 Bits7-2: UNUSED. Read = 000000b. Write = don't care. Bit1: PS1: UART1 Interrupt Priority Control. This bit sets the priority of the UART1 interrupt. 0: UART1 interrupt set to low priority level. 1: UART1 interrupts set to high priority level. Bit0: PVBUS: VBUS Level Interrupt Priority Control. This bit sets the priority of the VBUS interrupt. 0: VBUS interrupt set to low priority level. 1: VBUS interrupt set to high priority level. 94 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.13. IT01CF: INT0/INT1 Configuration R/W R/W R/W R/W R/W R/W R/W R/W Reset Value IN1PL Bit7 IN1SL2 Bit6 IN1SL1 Bit5 IN1SL0 Bit4 IN0PL Bit3 IN0SL2 Bit2 IN0SL1 Bit1 IN0SL0 Bit0 00000001 SFR Address: 0xE4 Note: Refer to SFR Definition 21.1 for INT0/1 edge- or level-sensitive interrupt selection. IN1PL: /INT1 Polarity 0: /INT1 input is active low. 1: /INT1 input is active high. Bits6-4: IN1SL2-0: /INT1 Port Pin Selection Bits These bits select which Port pin is assigned to /INT1. Note that this pin assignment is independent of the Crossbar; /INT1 will monitor the assigned Port pin without disturbing the peripheral that has been assigned the Port pin via the Crossbar. The Crossbar will not assign the Port pin to a peripheral if it is configured to skip the selected pin (accomplished by setting to `1' the corresponding bit in register P0SKIP). Bit7: IN1SL2-0 000 001 010 011 100 101 110 111 Bit3: /INT1 Port Pin P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 IN0PL: /INT0 Polarity 0: /INT0 interrupt is active low. 1: /INT0 interrupt is active high. Bits2-0: INT0SL2-0: /INT0 Port Pin Selection Bits These bits select which Port pin is assigned to /INT0. Note that this pin assignment is independent of the Crossbar. /INT0 will monitor the assigned Port pin without disturbing the peripheral that has been assigned the Port pin via the Crossbar. The Crossbar will not assign the Port pin to a peripheral if it is configured to skip the selected pin (accomplished by setting to `1' the corresponding bit in register P0SKIP). IN0SL2-0 000 001 010 011 100 101 110 111 /INT0 Port Pin P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 Rev. 0.5 95 C8051F340/1/2/3/4/5/6/7 9.4. Power Management Modes The CIP-51 core has two software programmable power management modes: Idle and Stop. Idle mode halts the CPU while leaving the peripherals and clocks active. In Stop mode, the CPU is halted, all interrupts, are inactive, and the internal oscillator is stopped (analog peripherals remain in their selected states; the external oscillator is not affected). Since clocks are running in Idle mode, power consumption is dependent upon the system clock frequency and the number of peripherals left in active mode before entering Idle. Stop mode consumes the least power. Figure 1.15 describes the Power Control Register (PCON) used to control the CIP-51's power management modes. Although the CIP-51 has Idle and Stop modes built in (as with any standard 8051 architecture), power management of the entire MCU is better accomplished through system clock and individual peripheral management. Each analog peripheral can be disabled when not in use and placed in low power mode. Digital peripherals, such as timers or serial buses, draw little power when they are not in use. Turning off the oscillators lowers power consumption considerably; however a reset is required to restart the MCU. The internal oscillator can be placed in Suspend mode (see Section "14. Oscillators" on page 135). In Suspend mode, the internal oscillator is stopped until a non-idle USB event is detected, or the VBUS input signal matches the polarity selected by the VBPOL bit in register REG0CN (SFR Definition 8.1). 9.4.1. Idle Mode Setting the Idle Mode Select bit (PCON.0) causes the CIP-51 to halt the CPU and enter Idle mode as soon as the instruction that sets the bit completes execution. All internal registers and memory maintain their original data. All analog and digital peripherals can remain active during Idle mode. Idle mode is terminated when an enabled interrupt is asserted or a reset occurs. The assertion of an enabled interrupt will cause the Idle Mode Selection bit (PCON.0) to be cleared and the CPU to resume operation. The pending interrupt will be serviced and the next instruction to be executed after the return from interrupt (RETI) will be the instruction immediately following the one that set the Idle Mode Select bit. If Idle mode is terminated by an internal or external reset, the CIP-51 performs a normal reset sequence and begins program execution at address 0x0000. If enabled, the Watchdog Timer (WDT) will eventually cause an internal watchdog reset and thereby terminate the Idle mode. This feature protects the system from an unintended permanent shutdown in the event of an inadvertent write to the PCON register. If this behavior is not desired, the WDT may be disabled by software prior to entering the Idle mode if the WDT was initially configured to allow this operation. This provides the opportunity for additional power savings, allowing the system to remain in the Idle mode indefinitely, waiting for an external stimulus to wake up the system. Refer to Section "11.6. PCA Watchdog Timer Reset" on page 104 for more information on the use and configuration of the WDT. 9.4.2. Stop Mode Setting the Stop Mode Select bit (PCON.1) causes the CIP-51 to enter Stop mode as soon as the instruction that sets the bit completes execution. In Stop mode the internal oscillator, CPU, and all digital peripherals are stopped; the state of the external oscillator circuit is not affected. Each analog peripheral (including the external oscillator circuit) may be shut down individually prior to entering Stop Mode. Stop mode can only be terminated by an internal or external reset. On reset, the CIP-51 performs the normal reset sequence and begins program execution at address 0x0000. If enabled, the Missing Clock Detector will cause an internal reset and thereby terminate the Stop mode. The Missing Clock Detector should be disabled if the CPU is to be put to in STOP mode for longer than the MCD timeout of 100 sec. 96 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 9.14. PCON: Power Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value GF5 Bit7 GF4 Bit6 GF3 Bit5 GF2 Bit4 GF1 Bit3 GF0 Bit2 STOP Bit1 IDLE Bit0 00000000 SFR Address: 0x87 Bits7-2: GF5-GF0: General Purpose Flags 5-0. These are general purpose flags for use under software control. Bit1: STOP: Stop Mode Select. Setting this bit will place the CIP-51 in Stop mode. This bit will always be read as 0. 1: CPU goes into Stop mode (internal oscillator stopped). Bit0: IDLE: Idle Mode Select. Setting this bit will place the CIP-51 in Idle mode. This bit will always be read as 0. 1: CPU goes into Idle mode. (Shuts off clock to CPU, but clock to Timers, Interrupts, Serial Ports, and Analog Peripherals are still active.) Rev. 0.5 97 C8051F340/1/2/3/4/5/6/7 NOTES: 98 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 10. Prefetch Engine The C8051F340/1/2/3/4/5/6/7 family of devices incorporate a 2-byte prefetch engine. Because the access time of the FLASH memory is 40 ns, and the minimum instruction time is roughly 20 ns, the prefetch engine is necessary for full-speed code execution. Instructions are read from FLASH memory two bytes at a time by the prefetch engine, and given to the CIP-51 processor core to execute. When running linear code (code without any jumps or branches), the prefetch engine allows instructions to be executed at full speed. When a code branch occurs, the processor may be stalled for up to two clock cycles while the next set of code bytes is retrieved from FLASH memory. The FLRT bit (FLSCL.4) determines how many clock cycles are used to read each set of two code bytes from FLASH. When operating from a system clock of 25 MHz or less, the FLRT bit should be set to `0' so that the prefetch engine takes only one clock cycle for each read. When operating with a system clock of greater than 25 MHz (up to 48 MHz), the FLRT bit should be set to `1', so that each prefetch code read lasts for two clock cycles. SFR Definition 10.1. PFE0CN: Prefetch Engine Control R Bit7 R Bit6 R/W R Bit4 R Bit3 R Bit2 R Bit1 R/W Reset Value PFEN Bit5 FLBWE Bit0 00100000 SFR Address: 0xAF Bits 7-6: Unused. Read = 00b; Write = Don't Care Bit 5: PFEN: Prefetch Enable. This bit enables the prefetch engine. 0: Prefetch engine is disabled. 1: Prefetch engine is enabled. Bits 4-1: Unused. Read = 0000b; Write = Don't Care Bit 0: FLBWE: FLASH Block Write Enable. This bit allows block writes to FLASH memory from software. 0: Each byte of a software FLASH write is written individually. 1: FLASH bytes are written in groups of two. Rev. 0.5 99 C8051F340/1/2/3/4/5/6/7 NOTES: 100 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 11. Reset Sources Reset circuitry allows the controller to be easily placed in a predefined default condition. On entry to this reset state, the following occur: * * * * CIP-51 halts program execution Special Function Registers (SFRs) are initialized to their defined reset values External Port pins are forced to a known state Interrupts and timers are disabled. All SFRs are reset to the predefined values noted in the SFR detailed descriptions. The contents of internal data memory are unaffected during a reset; any previously stored data is preserved. However, since the stack pointer SFR is reset, the stack is effectively lost even though the data on the stack is not altered. The Port I/O latches are reset to 0xFF (all logic ones) in open-drain mode. Weak pull-ups are enabled during and after the reset. For VDD Monitor and Power-On Resets, the /RST pin is driven low until the device exits the reset state. On exit from the reset state, the program counter (PC) is reset, and the system clock defaults to the internal oscillator. Refer to Section "14. Oscillators" on page 135 for information on selecting and configuring the system clock source. The Watchdog Timer is enabled with the system clock divided by 12 as its clock source (Section "22.3. Watchdog Timer Mode" on page 272 details the use of the Watchdog Timer). Program execution begins at location 0x0000. VDD Supply Monitor + Enable Px.x Px.x Comparator 0 + C0RSEF Power On Reset '0' (wired-OR) /RST Missing Clock Detector (oneshot) EN PCA WDT Reset Funnel Software Reset (SWRSF) MCD Enable Internal HF Oscillator Clock Multiplier System Clock WDT Enable Internal LF Oscillator XTAL1 XTAL2 External Oscillator Drive CIP-51 Microcontroller Core Extended Interrupt Handler USB Controller System Reset Enable EN Errant FLASH Operation VBUS Transition Clock Select Figure 11.1. Reset Sources Rev. 0.5 101 C8051F340/1/2/3/4/5/6/7 11.1. Power-On Reset During power-up, the device is held in a reset state and the /RST pin is driven low until VDD settles above VRST. A Power-On Reset delay (TPORDelay) occurs before the device is released from reset; this delay is typically less than 0.3 ms. Figure 11.2. plots the power-on and VDD monitor reset timing. On exit from a power-on reset, the PORSF flag (RSTSRC.1) is set by hardware to logic 1. When PORSF is set, all of the other reset flags in the RSTSRC Register are indeterminate (PORSF is cleared by all other resets). Since all resets cause program execution to begin at the same location (0x0000) software can read the PORSF flag to determine if a power-up was the cause of reset. The content of internal data memory should be assumed to be undefined after a power-on reset. The VDD monitor is enabled following a power-on reset. Software can force a power-on reset by writing `1' to the PINRSF bit in register RSTSRC. volts VDD VRST 2.70 2.4 2.0 1.0 VD D t Logic HIGH /RST Logic LOW TPORDelay VDD Monitor Reset Power-On Reset Figure 11.2. Power-On and VDD Monitor Reset Timing 102 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 11.2. Power-Fail Reset / VDD Monitor When a power-down transition or power irregularity causes VDD to drop below VRST, the power supply monitor will drive the /RST pin low and hold the CIP-51 in a reset state (see Figure 11.2). When VDD returns to a level above VRST, the CIP-51 will be released from the reset state. Note that even though internal data memory contents are not altered by the power-fail reset, it is impossible to determine if VDD dropped below the level required for data retention. If the PORSF flag reads `1', the data may no longer be valid. The VDD monitor is enabled after power-on resets; however its defined state (enabled/disabled) is not altered by any other reset source. For example, if the VDD monitor is enabled and a software reset is performed, the VDD monitor will still be enabled after the reset. Important Note: The VDD monitor must be enabled before it is selected as a reset source. Selecting the VDD monitor as a reset source before it is enabled and stabilized will cause a system reset. The procedure for configuring the VDD monitor as a reset source is shown below: Step 1. Enable the VDD monitor (VDM0CN.7 = `1'). Step 2. Wait for the VDD monitor to stabilize (see Table 11.1 for the VDD Monitor turn-on time). Step 3. Select the VDD monitor as a reset source (RSTSRC.1 = `1'). See Figure 11.2 for VDD monitor timing. See Table 11.1 for complete electrical characteristics of the VDD monitor. SFR Definition 11.1. VDM0CN: VDD Monitor Control R/W R Bit6 R Bit5 R Bit4 R Bit3 R Bit2 R Bit1 R Bit0 Reset Value VDMEN Bit7 VDDSTAT Reserved Reserved Reserved Reserved Reserved Reserved Variable SFR Address: 0xFF VDMEN: VDD Monitor Enable. This bit turns the VDD monitor circuit on/off. The VDD Monitor cannot generate system resets until it is also selected as a reset source in register RSTSRC (SFR Definition 11.2). The VDD Monitor must be allowed to stabilize before it is selected as a reset source. Selecting the VDD monitor as a reset source before it has stabilized will generate a system reset. See Table 11.1 for the minimum VDD Monitor turn-on time. The VDD Monitor is enabled following all POR resets. 0: VDD Monitor Disabled. 1: VDD Monitor Enabled. Bit6: VDDSTAT: VDD Status. This bit indicates the current power supply status (VDD Monitor output). 0: VDD is at or below the VDD monitor threshold. 1: VDD is above the VDD monitor threshold. Bits5-0: Reserved. Read = Variable. Write = don't care. Bit7: Rev. 0.5 103 C8051F340/1/2/3/4/5/6/7 11.3. External Reset The external /RST pin provides a means for external circuitry to force the device into a reset state. Asserting an active-low signal on the /RST pin generates a reset; an external pull-up and/or decoupling of the / RST pin may be necessary to avoid erroneous noise-induced resets. See Table 11.1 for complete /RST pin specifications. The PINRSF flag (RSTSRC.0) is set on exit from an external reset. 11.4. Missing Clock Detector Reset The Missing Clock Detector (MCD) is a one-shot circuit that is triggered by the system clock. If more than 100 s pass between rising edges on the system clock, the one-shot will time out and generate a reset. After a MCD reset, the MCDRSF flag (RSTSRC.2) will read `1', signifying the MCD as the reset source; otherwise, this bit reads `0'. Writing a `1' to the MCDRSF bit enables the Missing Clock Detector; writing a `0' disables it. The state of the /RST pin is unaffected by this reset. 11.5. Comparator0 Reset Comparator0 can be configured as a reset source by writing a `1' to the C0RSEF flag (RSTSRC.5). Comparator0 should be enabled and allowed to settle prior to writing to C0RSEF to prevent any turn-on chatter on the output from generating an unwanted reset. The Comparator0 reset is active-low: if the non-inverting input voltage (on CP0+) is less than the inverting input voltage (on CP0-), a system reset is generated. After a Comparator0 reset, the C0RSEF flag (RSTSRC.5) will read `1' signifying Comparator0 as the reset source; otherwise, this bit reads `0'. The state of the /RST pin is unaffected by this reset. 11.6. PCA Watchdog Timer Reset The programmable Watchdog Timer (WDT) function of the Programmable Counter Array (PCA) can be used to prevent software from running out of control during a system malfunction. The PCA WDT function can be enabled or disabled by software as described in Section "22.3. Watchdog Timer Mode" on page 272; the WDT is enabled and clocked by SYSCLK / 12 following any reset. If a system malfunction prevents user software from updating the WDT, a reset is generated and the WDTRSF bit (RSTSRC.5) is set to `1'. The state of the /RST pin is unaffected by this reset. 11.7. Flash Error Reset If a Flash read/write/erase or program read targets an illegal address, a system reset is generated. This may occur due to any of the following: * * * * * A Flash write or erase is attempted above user code space. This occurs when PSWE is set to `1' and a MOVX write operation is attempted above address 0x3DFF. A Flash read is attempted above user code space. This occurs when a MOVC operation is attempted above address 0x3DFF. A Program read is attempted above user code space. This occurs when user code attempts to branch to an address above 0x3DFF. A Flash read, write or erase attempt is restricted due to a Flash security setting (see Section "12.3. Security Options" on page 111). A Flash Write or Erase is attempted when the VDD monitor is not enabled. The FERROR bit (RSTSRC.6) is set following a Flash error reset. The state of the /RST pin is unaffected by this reset. 104 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 11.8. Software Reset Software may force a reset by writing a `1' to the SWRSF bit (RSTSRC.4). The SWRSF bit will read `1' following a software forced reset. The state of the /RST pin is unaffected by this reset. 11.9. USB Reset Writing `1' to the USBRSF bit in register RSTSRC selects USB0 as a reset source. With USB0 selected as a reset source, a system reset will be generated when either of the following occur: 1. RESET signaling is detected on the USB network. The USB Function Controller (USB0) must be enabled for RESET signaling to be detected. See Section "16. Universal Serial Bus Controller (USB0)" on page 163 for information on the USB Function Controller. 2. The voltage on the VBUS pin matches the polarity selected by the VBPOL bit in register REG0CN. See Section "8. Voltage Regulator (REG0)" on page 69 for details on the VBUS detection circuit. The USBRSF bit will read `1' following a USB reset. The state of the /RST pin is unaffected by this reset. Rev. 0.5 105 C8051F340/1/2/3/4/5/6/7 SFR Definition 11.2. RSTSRC: Reset Source R/W Bit7 R Bit6 R/W Bit5 R/W R Bit3 R/W Bit2 R/W R Reset Value USBRSF FERROR C0RSEF SWRSF Bit4 WDTRSF MCDRSF PORSF Bit1 PINRSF Bit0 Variable SFR Address: 0xEF Bit7: USBRSF: USB Reset Flag 0: Read: Last reset was not a USB reset; Write: USB resets disabled. 1: Read: Last reset was a USB reset; Write: USB resets enabled. FERROR: Flash Error Indicator. 0: Source of last reset was not a Flash read/write/erase error. 1: Source of last reset was a Flash read/write/erase error. C0RSEF: Comparator0 Reset Enable and Flag. 0: Read: Source of last reset was not Comparator0; Write: Comparator0 is not a reset source. 1: Read: Source of last reset was Comparator0; Write: Comparator0 is a reset source (active-low). SWRSF: Software Reset Force and Flag. 0: Read: Source of last reset was not a write to the SWRSF bit; Write: No Effect. 1: Read: Source of last was a write to the SWRSF bit; Write: Forces a system reset. WDTRSF: Watchdog Timer Reset Flag. 0: Source of last reset was not a WDT timeout. 1: Source of last reset was a WDT timeout. MCDRSF: Missing Clock Detector Flag. 0: Read: Source of last reset was not a Missing Clock Detector timeout; Write: Missing Clock Detector disabled. 1: Read: Source of last reset was a Missing Clock Detector timeout; Write: Missing Clock Detector enabled; triggers a reset if a missing clock condition is detected. PORSF: Power-On / VDD Monitor Reset Flag. This bit is set anytime a power-on reset occurs. Writing this bit selects/deselects the VDD monitor as a reset source. Note: writing `1' to this bit before the VDD monitor is enabled and stabilized can cause a system reset. See register VDM0CN (SFR Definition 11.1). 0: Read: Last reset was not a power-on or VDD monitor reset; Write: VDD monitor is not a reset source. 1: Read: Last reset was a power-on or VDD monitor reset; all other reset flags indeterminate; Write: VDD monitor is a reset source. PINRSF: HW Pin Reset Flag. 0: Source of last reset was not /RST pin. 1: Source of last reset was /RST pin. Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Note: For bits that act as both reset source enables (on a write) and reset indicator flags (on a read), read-modify-write instructions read and modify the source enable only. This applies to bits: USBRSF, C0RSEF, SWRSF, MCDRSF, PORSF. 106 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 11.1. Reset Electrical Characteristics -40 to +85 C unless otherwise specified. Parameter Conditions IOL = 8.5 mA, VDD = 2.7 to 3.6 V /RST Output Low Voltage /RST Input High Voltage /RST Input Low Voltage /RST Input Pull-Up Current VDD POR Threshold (VRST) Missing Clock Detector Timeout Reset Time Delay Minimum /RST Low Time to Generate a System Reset VDD Monitor Turn-on Time VDD Monitor Supply Current Min 0.7 x VDD Typ Max 0.6 0.3 x VDD 40 2.70 500 Units V V A V s s s s A /RST = 0.0 V 2.40 Time from last system clock rising edge to reset initiation Delay between release of any reset source and code execution at location 0x0000 100 5.0 15 100 25 2.55 220 20 50 Rev. 0.5 107 C8051F340/1/2/3/4/5/6/7 NOTES: 108 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 12. Flash Memory On-chip, re-programmable Flash memory is included for program code and non-volatile data storage. The Flash memory can be programmed in-system through the C2 interface or by software using the MOVX instruction. Once cleared to logic 0, a Flash bit must be erased to set it back to logic 1. Flash bytes would typically be erased (set to 0xFF) before being reprogrammed. The write and erase operations are automatically timed by hardware for proper execution; data polling to determine the end of the write/erase operation is not required. Code execution is stalled during a Flash write/erase operation. Refer to Table 12.1 for complete Flash memory electrical characteristics. 12.1. Programming The Flash Memory The simplest means of programming the Flash memory is through the C2 interface using programming tools provided by Silicon Labs or a third party vendor. This is the only means for programming a non-initialized device. For details on the C2 commands to program Flash memory, see Section "23. C2 Interface" on page 279. To ensure the integrity of Flash contents, the VDD Monitor must be enabled before writing and/or erasing Flash memory from software. If a write or erase attempt is made while the VDD monitor is disabled, it will cause a Flash Error device reset. 12.1.1. Flash Lock and Key Functions Flash writes and erases by user software are protected with a lock and key function. The Flash Lock and Key Register (FLKEY) must be written with the correct key codes, in sequence, before Flash operations may be performed. The key codes are: 0xA5, 0xF1. The timing does not matter, but the codes must be written in order. If the key codes are written out of order, or the wrong codes are written, Flash writes and erases will be disabled until the next system reset. Flash writes and erases will also be disabled if a Flash write or erase is attempted before the key codes have been written properly. The Flash lock resets after each write or erase; the key codes must be written again before a following Flash operation can be performed. The FLKEY register is detailed in SFR Definition 12.2. 12.1.2. Flash Erase Procedure The Flash memory can be programmed by software using the MOVX write instruction with the address and data byte to be programmed provided as normal operands. Before writing to Flash memory using MOVX, Flash write operations must be enabled by: (1) Writing the Flash key codes in sequence to the Flash Lock register (FLKEY); and (2) Setting the PSWE Program Store Write Enable bit (PSCTL.0) to logic 1 (this directs the MOVX writes to target Flash memory). The PSWE bit remains set until cleared by software. A write to Flash memory can clear bits to logic 0 but cannot set them; only an erase operation can set bits to logic 1 in Flash. A byte location to be programmed must be erased before a new value is written. The Flash memory is organized in 512-byte pages. The erase operation applies to an entire page (setting all bytes in the page to 0xFF). To erase an entire 512-byte page, perform the following steps: Disable interrupts (recommended). Write the first key code to FLKEY: 0xA5. Write the second key code to FLKEY: 0xF1. Set the PSEE bit (register PSCTL). Set the PSWE bit (register PSCTL). Using the MOVX instruction, write a data byte to any location within the 512-byte page to be erased. Step 7. Clear the PSWE bit (register PSCTL). Step 8. Clear the PSEE bit (register PSCTI). Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Rev. 0.5 109 C8051F340/1/2/3/4/5/6/7 12.1.3. Flash Write Procedure Bytes in Flash memory can be written one byte at a time, or in groups of two. The FLBWE bit in register PFE0CN (SFR Definition 10.1) controls whether a single byte or a block of two bytes is written to Flash during a write operation. When FLBWE is cleared to `0', the Flash will be written one byte at a time. When FLBWE is set to `1', the Flash will be written in two-byte blocks. Block writes are performed in the same amount of time as single-byte writes, which can save time when storing large amounts of data to Flash memory.During a single-byte write to Flash, bytes are written individually, and a Flash write will be performed after each MOVX write instruction. The recommended procedure for writing Flash in single bytes is: Disable interrupts. Clear the FLBWE bit (register PFE0CN) to select single-byte write mode. Set the PSWE bit (register PSCTL). Clear the PSEE bit (register PSCTL). Write the first key code to FLKEY: 0xA5. Write the second key code to FLKEY: 0xF1. Using the MOVX instruction, write a single data byte to the desired location within the 512-byte sector. Step 8. Clear the PSWE bit. Step 9. Re-enable interrupts. Steps 5-7 must be repeated for each byte to be written. For block Flash writes, the Flash write procedure is only performed after the last byte of each block is written with the MOVX write instruction. A Flash write block is two bytes long, from even addresses to odd addresses. Writes must be performed sequentially (i.e. addresses ending in 0b and 1b must be written in order). The Flash write will be performed following the MOVX write that targets the address ending in 1b. If a byte in the block does not need to be updated in Flash, it should be written to 0xFF. The recommended procedure for writing Flash in blocks is: Disable interrupts. Set the FLBWE bit (register PFE0CN) to select block write mode. Set the PSWE bit (register PSCTL). Clear the PSEE bit (register PSCTL). Write the first key code to FLKEY: 0xA5. Write the second key code to FLKEY: 0xF1. Using the MOVX instruction, write the first data byte to the even block location (ending in 0b). Step 8. Write the first key code to FLKEY: 0xA5. Step 9. Write the second key code to FLKEY: 0xF1. Step 10. Using the MOVX instruction, write the second data byte to the odd block location (ending in 1b). Step 11. Clear the PSWE bit. Step 12. Re-enable interrupts. Steps 5-10 must be repeated for each block to be written. Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. 110 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 12.1. Flash Electrical Characteristics Parameter Flash Size Endurance Erase Cycle Time Write Cycle Time Conditions C8051F340/2/4/6* C8051F341/3/5/7 25 MHz System Clock 25 MHz System Clock Min 65536* 32768 20k 10 40 Typ Max Units Bytes Bytes Erase/Write ms s 100k 15 55 20 70 *Note: 1024 bytes at location 0xFC00 to 0xFFFF are reserved. 12.2. Non-volatile Data Storage The Flash memory can be used for non-volatile data storage as well as program code. This allows data such as calibration coefficients to be calculated and stored at run time. Data is written using the MOVX write instruction and read using the MOVC instruction. Note: MOVX read instructions always target XRAM. 12.3. Security Options The CIP-51 provides security options to protect the Flash memory from inadvertent modification by software as well as to prevent the viewing of proprietary program code and constants. The Program Store Write Enable (bit PSWE in register PSCTL) and the Program Store Erase Enable (bit PSEE in register PSCTL) bits protect the Flash memory from accidental modification by software. PSWE must be explicitly set to `1' before software can modify the Flash memory; both PSWE and PSEE must be set to `1' before software can erase Flash memory. Additional security features prevent proprietary program code and data constants from being read or altered across the C2 interface. A Security Lock Byte located at the last byte of Flash user space offers protection of the Flash program memory from access (reads, writes, or erases) by unprotected code or the C2 interface. The Flash security mechanism allows the user to lock n 512-byte Flash pages, starting at page 0 (addresses 0x0000 to 0x01FF), where n is the 1's complement number represented by the Security Lock Byte. Note that the page containing the Flash Security Lock Byte is also locked when any other Flash pages are locked. See example below. Security Lock Byte: 1's Complement: Flash pages locked: Addresses locked: 11111101b 00000010b 3 (2 + Flash Lock Byte Page) First two pages of Flash: 0x0000 to 0x03FF Flash Lock Byte Page: (0xFA00 to 0xFBFF for 64k devices; 0x7E00 to 0x7FFF for 32k devices) Rev. 0.5 111 C8051F340/1/2/3/4/5/6/7 C8051F340/2/4/6 Reserved 0xFC00 Lock Byte 0xFBFF 0xFBFE 0xFA00 Locked when any other FLASH pages are locked C8051F341/3/5/7 Lock Byte 0x7FFF 0x7FFE 0x7E00 FLASH memory organized in 512-byte pages Unlocked FLASH Pages Access limit set according to the FLASH security lock byte 0x0000 Unlocked FLASH Pages 0x0000 Figure 12.1. Flash Program Memory Map and Security Byte 112 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 The level of FLASH security depends on the FLASH access method. The three FLASH access methods that can be restricted are reads, writes, and erases from the C2 debug interface, user firmware executing on unlocked pages, and user firmware executing on locked pages. Accessing FLASH from the C2 debug interface: Any unlocked page may be read, written, or erased. Locked pages cannot be read, written, or erased. The page containing the Lock Byte may be read, written, or erased if it is unlocked. Reading the contents of the Lock Byte is always permitted. Locking additional pages (changing `1's to `0's in the Lock Byte) is always permitted. Unlocking FLASH pages (changing `0's to `1's in the Lock Byte) requires the C2 Device Erase command, which erases all FLASH pages including the page containing the Lock Byte and the Lock Byte itself. 7. The Reserved Area cannot be read, written, or erased. 1. 2. 3. 4. 5. 6. Accessing FLASH from user firmware executing on an unlocked page: 1. Any unlocked page except the page containing the Lock Byte may be read, written, or erased. 2. Locked pages cannot be read, written, or erased. 3. The page containing the Lock Byte cannot be erased. It may be read or written only if it is unlocked. 4. Reading the contents of the Lock Byte is always permitted. 5. Locking additional pages (changing `1's to `0's in the Lock Byte) is always permitted. 6. Unlocking FLASH pages (changing `0's to `1's in the Lock Byte) is not permitted. 7. The Reserved Area cannot be read, written, or erased. Any attempt to access the reserved area, or any other locked page, will result in a FLASH Error device reset. Accessing FLASH from user firmware executing on a locked page: 1. 2. 3. 4. 5. 6. 7. Any unlocked page except the page containing the Lock Byte may be read, written, or erased. Any locked page except the page containing the Lock Byte may be read, written, or erased. The page containing the Lock Byte cannot be erased. It may only be read or written. Reading the contents of the Lock Byte is always permitted. Locking additional pages (changing `1's to `0's in the Lock Byte) is always permitted. Unlocking FLASH pages (changing `0's to `1's in the Lock Byte) is not permitted. The Reserved Area cannot be read, written, or erased. Any attempt to access the reserved area, or any other locked page, will result in a FLASH Error device reset. Rev. 0.5 113 C8051F340/1/2/3/4/5/6/7 SFR Definition 12.1. PSCTL: Program Store R/W Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 Bit6 Bit5 Bit4 Bit3 Reserved Bit2 PSEE Bit1 PSWE Bit0 00000000 SFR Address: 0x8F Bits7-3: Unused: Read = 00000b. Write = don't care. Bit2: Reserved. Read = 0b. Must Write = 0b. Bit1: PSEE: Program Store Erase Enable Setting this bit (in combination with PSWE) allows an entire page of Flash program memory to be erased. If this bit is logic 1 and Flash writes are enabled (PSWE is logic 1), a write to Flash memory using the MOVX instruction will erase the entire page that contains the location addressed by the MOVX instruction. The value of the data byte written does not matter. 0: Flash program memory erasure disabled. 1: Flash program memory erasure enabled. Bit0: PSWE: Program Store Write Enable Setting this bit allows writing a byte of data to the Flash program memory using the MOVX write instruction. The Flash location should be erased before writing data. 0: Writes to Flash program memory disabled. 1: Writes to Flash program memory enabled; the MOVX write instruction targets Flash memory. SFR Definition 12.2. FLKEY: Flash Lock and Key R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xB7 Bits-0: FLKEY: Flash Lock and Key Register Write: This register must be written to before Flash writes or erases can be performed. Flash remains locked until this register is written to with the following key codes: 0xA5, 0xF1. The timing of the writes does not matter, as long as the codes are written in order. The key codes must be written for each Flash write or erase operation. Flash will be locked until the next system reset if the wrong codes are written or if a Flash operation is attempted before the codes have been written correctly. Read: When read, bits 1-0 indicate the current Flash lock state. 00: Flash is write/erase locked. 01: The first key code has been written (0xA5). 10: Flash is unlocked (writes/erases allowed). 11: Flash writes/erases disabled until the next reset. 114 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 12.3. FLSCL: Flash Scale R/W R/W Bit6 R/W Bit5 R/W R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value SFR Address: FOSE Bit7 Reserved Reserved FLRT Bit4 Reserved Reserved Reserved Reserved 10000000 0xB6 FOSE: Flash One-shot Enable This bit enables the Flash read one-shot. When the Flash one-shot disabled, the Flash sense amps are enabled for a full clock cycle during Flash reads. At system clock frequencies below 10 MHz, disabling the Flash one-shot will increase system power consumption. 0: Flash one-shot disabled. 1: Flash one-shot enabled. Bits6-5: RESERVED. Read = 00b. Must Write 00b. Bit 4: FLRT: FLASH Read Time. This bit should be programmed to the smallest allowed value, according to the system clock speed. 0: SYSCLK <= 25 MHz. 1: SYSCLK <= 48 MHz. Bits3-0: RESERVED. Read = 0000b. Must Write 0000b. Bits7: Rev. 0.5 115 C8051F340/1/2/3/4/5/6/7 NOTES: 116 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 13. External Data Memory Interface and On-Chip XRAM 4k Bytes (C8051F340/2/4/6) or 2k Bytes (C8051F341/3/5/7) of RAM are included on-chip, and mapped into the external data memory space (XRAM). The 1k Bytes of USB FIFO space can also be mapped into XRAM address space for additional general-purpose data storage. Additionally, an External Memory Interface (EMIF) is available on the C8051F340/1/4/5 devices, which can be used to access off-chip data memories and memory-mapped devices connected to the GPIO ports. The external memory space may be accessed using the external move instruction (MOVX) and the data pointer (DPTR), or using the MOVX indirect addressing mode using R0 or R1. If the MOVX instruction is used with an 8-bit address operand (such as @R1), then the high byte of the 16-bit address is provided by the External Memory Interface Control Register (EMI0CN, shown in SFR Definition 13.1). Note: the MOVX instruction can also be used for writing to the FLASH memory. See Section "12. Flash Memory" on page 109 for details. The MOVX instruction accesses XRAM by default. 13.1. Accessing XRAM The XRAM memory space is accessed using the MOVX instruction. The MOVX instruction has two forms, both of which use an indirect addressing method. The first method uses the Data Pointer, DPTR, a 16-bit register which contains the effective address of the XRAM location to be read from or written to. The second method uses R0 or R1 in combination with the EMI0CN register to generate the effective XRAM address. Examples of both of these methods are given below. 13.1.1. 16-Bit MOVX Example The 16-bit form of the MOVX instruction accesses the memory location pointed to by the contents of the DPTR register. The following series of instructions reads the value of the byte at address 0x1234 into the accumulator A: MOV MOVX DPTR, #1234h A, @DPTR ; load DPTR with 16-bit address to read (0x1234) ; load contents of 0x1234 into accumulator A The above example uses the 16-bit immediate MOV instruction to set the contents of DPTR. Alternately, the DPTR can be accessed through the SFR registers DPH, which contains the upper 8-bits of DPTR, and DPL, which contains the lower 8-bits of DPTR. 13.1.2. 8-Bit MOVX Example The 8-bit form of the MOVX instruction uses the contents of the EMI0CN SFR to determine the upper 8-bits of the effective address to be accessed and the contents of R0 or R1 to determine the lower 8-bits of the effective address to be accessed. The following series of instructions read the contents of the byte at address 0x1234 into the accumulator A. MOV MOV MOVX EMI0CN, #12h R0, #34h a, @R0 ; load high byte of address into EMI0CN ; load low byte of address into R0 (or R1) ; load contents of 0x1234 into accumulator A Rev. 0.5 117 C8051F340/1/2/3/4/5/6/7 13.2. Accessing USB FIFO Space The C8051F340/1/2/3/4/5/6/7 include 1k of RAM which functions as USB FIFO space. Figure 13.1 shows an expanded view of the FIFO space and user XRAM. FIFO space is normally accessed via USB FIFO registers; see Section "16.5. FIFO Management" on page 171 for more information on accessing these FIFOs. The MOVX instruction should not be used to load or modify USB data in the FIFO space. Unused areas of the USB FIFO space may be used as general purpose XRAM if necessary. The FIFO block operates on the USB clock domain; thus the USB clock must be active when accessing FIFO space. Note that the number of SYSCLK cycles required by the MOVX instruction is increased when accessing USB FIFO space. To access the FIFO RAM directly using MOVX instructions, The USBFAE bit in register EMI0CF must be set to `1'. When this bit is set, the USB FIFO space is mapped into XRAM space at addresses 0x0400 to 0x07FF. The normal XRAM (on-chip or external) at the same addresses cannot be accessed when the USBFAE bit is set to `1'. Important Note: The USB clock must be active when accessing FIFO space. 0xFFFF On/Off-Chip XRAM 0x0800 0x07FF Endpoint0 (64 bytes) 0x07C0 0x07BF Endpoint1 (128 bytes) 0x0740 0x073F Endpoint2 (256 bytes) 0x0640 0x063F USB FIFO Space (USB Clock Domain) Endpoint3 (512 bytes) 0x0440 0x043F Free (64 bytes) 0x0400 0x03FF On/Off-Chip XRAM 0x0000 Figure 13.1. USB FIFO Space and XRAM Memory Map with USBFAE set to `1' 118 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 13.3. Configuring the External Memory Interface Configuring the External Memory Interface consists of five steps: 1. Configure the Output Modes of the associated port pins as either push-pull or open-drain (push-pull is most common), and skip the associated pins in the crossbar. 2. Configure Port latches to "park" the EMIF pins in a dormant state (usually by setting them to logic `1'). 3. Select Multiplexed mode or Non-multiplexed mode. 4. Select the memory mode (on-chip only, split mode without bank select, split mode with bank select, or off-chip only). 5. Set up timing to interface with off-chip memory or peripherals. Each of these five steps is explained in detail in the following sections. The Port selection, Multiplexed mode selection, and Mode bits are located in the EMI0CF register shown in SFR Definition 13.2. 13.4. Port Configuration The External Memory Interface appears on Ports 4, 3, 2, and 1 when it is used for off-chip memory access. When the EMIF is used, the Crossbar should be configured to skip over the control lines P1.7 (/WR), P1.6 (/RD), and if multiplexed mode is selected P1.3 (ALE) using the P1SKIP register. For more information about configuring the Crossbar, see Section "Figure 15.1. Port I/O Functional Block Diagram (Port 0 through Port 3)" on page 147. The External Memory Interface claims the associated Port pins for memory operations ONLY during the execution of an off-chip MOVX instruction. Once the MOVX instruction has completed, control of the Port pins reverts to the Port latches or to the Crossbar settings for those pins. See Section "15. Port Input/ Output" on page 147 for more information about the Crossbar and Port operation and configuration. The Port latches should be explicitly configured to `park' the External Memory Interface pins in a dormant state, most commonly by setting them to a logic 1. During the execution of the MOVX instruction, the External Memory Interface will explicitly disable the drivers on all Port pins that are acting as Inputs (Data[7:0] during a READ operation, for example). The Output mode of the Port pins (whether the pin is configured as Open-Drain or Push-Pull) is unaffected by the External Memory Interface operation, and remains controlled by the PnMDOUT registers. In most cases, the output modes of all EMIF pins should be configured for push-pull mode. Rev. 0.5 119 C8051F340/1/2/3/4/5/6/7 SFR Definition 13.1. EMI0CN: External Memory Interface Control R/W R/W R/W R/W R/W R/W R/W R/W Bit0 SFR Address: 0xAA Reset Value PGSEL7 Bit7 PGSEL6 Bit6 PGSEL5 Bit5 PGSEL4 Bit4 PGSEL3 Bit3 PGSEL2 Bit2 PGSEL1 Bit1 PGSEL0 00000000 Bits7-0: PGSEL[7:0]: XRAM Page Select Bits. The XRAM Page Select Bits provide the high byte of the 16-bit external data memory address when using an 8-bit MOVX command, effectively selecting a 256-byte page of RAM. 0x00: 0x0000 to 0x00FF 0x01: 0x0100 to 0x01FF ... 0xFE: 0xFE00 to 0xFEFF 0xFF: 0xFF00 to 0xFFFF 120 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 13.2. EMI0CF: External Memory Configuration R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 USBFAE Bit6 Bit5 EMD2 Bit4 EMD1 Bit3 EMD0 Bit2 EALE1 Bit1 EALE0 Bit0 00000011 SFR Address: 0x85 Bit7: Bit6: Unused. Read = 0b. Write = don't care. USBFAE: USB FIFO Access Enable. 0: USB FIFO RAM not available through MOVX instructions. 1: USB FIFO RAM available using MOVX instructions. The 1k of USB RAM will be mapped in XRAM space at addresses 0x0400 to 0x07FF. The USB clock must be active to access this area with MOVX instructions. Bit5: Unused. Read = 0b. Write = don't care. Bit4: EMD2: EMIF Multiplex Mode Select. 0: EMIF operates in multiplexed address/data mode. 1: EMIF operates in non-multiplexed mode (separate address and data pins). Bits3-2: EMD1-0: EMIF Operating Mode Select. These bits control the operating mode of the External Memory Interface. 00: Internal Only: MOVX accesses on-chip XRAM only. All effective addresses alias to on-chip memory space. 01: Split Mode without Bank Select: Accesses below the 8k boundary are directed on-chip. Accesses above the 8k boundary are directed off-chip. 8-bit off-chip MOVX operations use the current contents of the Address High port latches to resolve upper address byte. Note that in order to access off-chip space, EMI0CN must be set to a page that is not contained in the on-chip address space. 10: Split Mode with Bank Select: Accesses below the 8k boundary are directed on-chip. Accesses above the 8k boundary are directed off-chip. 8-bit off-chip MOVX operations use the contents of EMI0CN to determine the high-byte of the address. 11: External Only: MOVX accesses off-chip XRAM only. On-chip XRAM is not visible to the CPU. Bits1-0: EALE1-0: ALE Pulse-Width Select Bits (only has effect when EMD2 = 0). 00: ALE high and ALE low pulse width = 1 SYSCLK cycle. 01: ALE high and ALE low pulse width = 2 SYSCLK cycles. 10: ALE high and ALE low pulse width = 3 SYSCLK cycles. 11: ALE high and ALE low pulse width = 4 SYSCLK cycles. Rev. 0.5 121 C8051F340/1/2/3/4/5/6/7 13.5. Multiplexed and Non-multiplexed Selection The External Memory Interface is capable of acting in a Multiplexed mode or a Non-multiplexed mode, depending on the state of the EMD2 (EMI0CF.4) bit. 13.5.1. Multiplexed Configuration In Multiplexed mode, the Data Bus and the lower 8-bits of the Address Bus share the same Port pins: AD[7:0]. In this mode, an external latch (74HC373 or equivalent logic gate) is used to hold the lower 8-bits of the RAM address. The external latch is controlled by the ALE (Address Latch Enable) signal, which is driven by the External Memory Interface logic. An example of a Multiplexed Configuration is shown in Figure 13.2. In Multiplexed mode, the external MOVX operation can be broken into two phases delineated by the state of the ALE signal. During the first phase, ALE is high and the lower 8-bits of the Address Bus are presented to AD[7:0]. During this phase, the address latch is configured such that the `Q' outputs reflect the states of the `D' inputs. When ALE falls, signaling the beginning of the second phase, the address latch outputs remain fixed and are no longer dependent on the latch inputs. Later in the second phase, the Data Bus controls the state of the AD[7:0] port at the time /RD or /WR is asserted. See Section "13.7.2. Multiplexed Mode" on page 130 for more information. A[15:8] ADDRESS BUS 74HC373 A[15:8] E M I F ALE AD[7:0] ADDRESS/DATA BUS VDD G D Q A[7:0] 64K X 8 SRAM (Optional) 8 I/O[7:0] CE WE OE /WR /RD Figure 13.2. Multiplexed Configuration Example 122 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 13.5.2. Non-multiplexed Configuration In Non-multiplexed mode, the Data Bus and the Address Bus pins are not shared. An example of a Non-multiplexed Configuration is shown in Figure 13.3. See Section "13.7.1. Non-multiplexed Mode" on page 127 for more information about Non-multiplexed operation. E M I F A[15:0] ADDRESS BUS VDD A[15:0] (Optional) 8 D[7:0] DATA BUS 64K X 8 SRAM I/O[7:0] CE WE OE /WR /RD Figure 13.3. Non-multiplexed Configuration Example 13.6. Memory Mode Selection The external data memory space can be configured in one of four modes, shown in Figure 13.4, based on the EMIF Mode bits in the EMI0CF register (SFR Definition 13.2). These modes are summarized below. More information about the different modes can be found in Section "13.7. Timing" on page 125. EMI0CF[3:2] = 00 0xFFFF On-Chip XRAM EMI0CF[3:2] = 01 0xFFFF EMI0CF[3:2] = 10 0xFFFF EMI0CF[3:2] = 11 0xFFFF On-Chip XRAM Off-Chip Memory (No Bank Select) Off-Chip Memory (Bank Select) Off-Chip Memory On-Chip XRAM On-Chip XRAM On-Chip XRAM On-Chip XRAM On-Chip XRAM 0x0000 0x0000 0x0000 0x0000 On-Chip XRAM Figure 13.4. EMIF Operating Modes Rev. 0.5 123 C8051F340/1/2/3/4/5/6/7 13.6.1. Internal XRAM Only When EMI0CF.[3:2] are set to `00', all MOVX instructions will target the internal XRAM space on the device. Memory accesses to addresses beyond the populated space will wrap on 2k or 4k boundaries (depending on the RAM available on the device). As an example, the addresses 0x1000 and 0x2000 both evaluate to address 0x0000 in on-chip XRAM space. * * 8-bit MOVX operations use the contents of EMI0CN to determine the high-byte of the effective address and R0 or R1 to determine the low-byte of the effective address. 16-bit MOVX operations use the contents of the 16-bit DPTR to determine the effective address. 13.6.2. Split Mode without Bank Select When EMI0CF.[3:2] are set to `01', the XRAM memory map is split into two areas, on-chip space and off-chip space. * * * Effective addresses below the internal XRAM size boundary will access on-chip XRAM space. Effective addresses above the internal XRAM size boundary will access off-chip space. 8-bit MOVX operations use the contents of EMI0CN to determine whether the memory access is on-chip or off-chip. However, in the "No Bank Select" mode, an 8-bit MOVX operation will not drive the upper 8-bits A[15:8] of the Address Bus during an off-chip access. This allows the user to manipulate the upper address bits at will by setting the Port state directly via the port latches. This behavior is in contrast with "Split Mode with Bank Select" described below. The lower 8-bits of the Address Bus A[7:0] are driven, determined by R0 or R1. 16-bit MOVX operations use the contents of DPTR to determine whether the memory access is on-chip or off-chip, and unlike 8-bit MOVX operations, the full 16-bits of the Address Bus A[15:0] are driven during the off-chip transaction. * 124 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 13.6.3. Split Mode with Bank Select When EMI0CF.[3:2] are set to `10', the XRAM memory map is split into two areas, on-chip space and off-chip space. * * * Effective addresses below the internal XRAM size boundary will access on-chip XRAM space. Effective addresses above the internal XRAM size boundary will access off-chip space. 8-bit MOVX operations use the contents of EMI0CN to determine whether the memory access is on-chip or off-chip. The upper 8-bits of the Address Bus A[15:8] are determined by EMI0CN, and the lower 8-bits of the Address Bus A[7:0] are determined by R0 or R1. All 16-bits of the Address Bus A[15:0] are driven in "Bank Select" mode. 16-bit MOVX operations use the contents of DPTR to determine whether the memory access is on-chip or off-chip, and the full 16-bits of the Address Bus A[15:0] are driven during the off-chip transaction. * 13.6.4. External Only When EMI0CF[3:2] are set to `11', all MOVX operations are directed to off-chip space. On-chip XRAM is not visible to the CPU. This mode is useful for accessing off-chip memory located between 0x0000 and the internal XRAM size boundary. * 8-bit MOVX operations ignore the contents of EMI0CN. The upper Address bits A[15:8] are not driven (identical behavior to an off-chip access in "Split Mode without Bank Select" described above). This allows the user to manipulate the upper address bits at will by setting the Port state directly. The lower 8-bits of the effective address A[7:0] are determined by the contents of R0 or R1. 16-bit MOVX operations use the contents of DPTR to determine the effective address A[15:0]. The full 16-bits of the Address Bus A[15:0] are driven during the off-chip transaction. * 13.7. Timing The timing parameters of the External Memory Interface can be configured to enable connection to devices having different setup and hold time requirements. The Address Setup time, Address Hold time, / RD and /WR strobe widths, and in multiplexed mode, the width of the ALE pulse are all programmable in units of SYSCLK periods through EMI0TC, shown in SFR Definition 13.3, and EMI0CF[1:0]. The timing for an off-chip MOVX instruction can be calculated by adding 4 SYSCLK cycles to the timing parameters defined by the EMI0TC register. Assuming non-multiplexed operation, the minimum execution time for an off-chip XRAM operation is 5 SYSCLK cycles (1 SYSCLK for /RD or /WR pulse + 4 SYSCLKs). For multiplexed operations, the Address Latch Enable signal will require a minimum of 2 additional SYSCLK cycles. Therefore, the minimum execution time for an off-chip XRAM operation in multiplexed mode is 7 SYSCLK cycles (2 for /ALE + 1 for /RD or /WR + 4). The programmable setup and hold times default to the maximum delay settings after a reset. Table 13.1 lists the AC parameters for the External Memory Interface, and Figure 13.5 through Figure 13.10 show the timing diagrams for the different External Memory Interface modes and MOVX operations. Rev. 0.5 125 C8051F340/1/2/3/4/5/6/7 SFR Definition 13.3. EMI0TC: External Memory Timing Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value EAS1 Bit7 EAS0 Bit6 ERW3 Bit5 EWR2 Bit4 EWR1 Bit3 EWR0 Bit2 EAH1 Bit1 EAH0 Bit0 11111111 SFR Address: 0x84 Bits7-6: EAS1-0: EMIF Address Setup Time Bits. 00: Address setup time = 0 SYSCLK cycles. 01: Address setup time = 1 SYSCLK cycle. 10: Address setup time = 2 SYSCLK cycles. 11: Address setup time = 3 SYSCLK cycles. Bits5-2: EWR3-0: EMIF /WR and /RD Pulse-Width Control Bits. 0000: /WR and /RD pulse width = 1 SYSCLK cycle. 0001: /WR and /RD pulse width = 2 SYSCLK cycles. 0010: /WR and /RD pulse width = 3 SYSCLK cycles. 0011: /WR and /RD pulse width = 4 SYSCLK cycles. 0100: /WR and /RD pulse width = 5 SYSCLK cycles. 0101: /WR and /RD pulse width = 6 SYSCLK cycles. 0110: /WR and /RD pulse width = 7 SYSCLK cycles. 0111: /WR and /RD pulse width = 8 SYSCLK cycles. 1000: /WR and /RD pulse width = 9 SYSCLK cycles. 1001: /WR and /RD pulse width = 10 SYSCLK cycles. 1010: /WR and /RD pulse width = 11 SYSCLK cycles. 1011: /WR and /RD pulse width = 12 SYSCLK cycles. 1100: /WR and /RD pulse width = 13 SYSCLK cycles. 1101: /WR and /RD pulse width = 14 SYSCLK cycles. 1110: /WR and /RD pulse width = 15 SYSCLK cycles. 1111: /WR and /RD pulse width = 16 SYSCLK cycles. Bits1-0: EAH1-0: EMIF Address Hold Time Bits. 00: Address hold time = 0 SYSCLK cycles. 01: Address hold time = 1 SYSCLK cycle. 10: Address hold time = 2 SYSCLK cycles. 11: Address hold time = 3 SYSCLK cycles. 126 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 13.7.1. Non-multiplexed Mode 13.7.1.1.16-bit MOVX: EMI0CF[4:2] = `101', `110', or `111'. Nonmuxed 16-bit WRITE ADDR[15:8] P2 EMIF ADDRESS (8 MSBs) from DPH P2 ADDR[7:0] P3 EMIF ADDRESS (8 LSBs) from DPL P3 DATA[7:0] P4 T T ACS EMIF WRITE DATA WDS P4 T WDH ACH T ACW T /WR P1.7 P1.7 /RD P1.6 P1.6 Nonmuxed 16-bit READ ADDR[15:8] P2 EMIF ADDRESS (8 MSBs) from DPH P2 ADDR[7:0] P3 EMIF ADDRESS (8 LSBs) from DPL P3 DATA[7:0] P4 EMIF READ DATA T T ACS RDS P4 T RDH T ACW T ACH /RD P1.6 P1.6 /WR P1.7 P1.7 Figure 13.5. Non-multiplexed 16-bit MOVX Timing Rev. 0.5 127 C8051F340/1/2/3/4/5/6/7 13.7.1.2.8-bit MOVX without Bank Select: EMI0CF[4:2] = `101' or `111'. Nonmuxed 8-bit WRITE without Bank Select ADDR[15:8] P2 ADDR[7:0] P3 EMIF ADDRESS (8 LSBs) from R0 or R1 P3 DATA[7:0] P4 T T ACS EMIF WRITE DATA WDS P4 T WDH ACH T ACW T /WR P1.7 P1.7 /RD P1.6 P1.6 Nonmuxed 8-bit READ without Bank Select ADDR[15:8] P2 ADDR[7:0] P3 EMIF ADDRESS (8 LSBs) from R0 or R1 P3 DATA[7:0] P4 EMIF READ DATA T T ACS RDS P4 T RDH T ACW T ACH /RD P1.6 P1.6 /WR P1.7 P1.7 Figure 13.6. Non-multiplexed 8-bit MOVX without Bank Select Timing 128 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 13.7.1.3.8-bit MOVX with Bank Select: EMI0CF[4:2] = `110'. Muxed 8-bit WRITE with Bank Select ADDR[15:8] P3 EMIF ADDRESS (8 MSBs) from EMI0CN EMIF ADDRESS (8 LSBs) from R0 or R1 T ALEH P3 AD[7:0] P4 EMIF WRITE DATA P4 T ALEL ALE P1.3 T T ACS WDS P1.3 T T ACW WDH ACH T /WR P1.7 P1.7 /RD P1.6 P1.6 Muxed 8-bit READ with Bank Select ADDR[15:8] P3 EMIF ADDRESS (8 MSBs) from EMI0CN EMIF ADDRESS (8 LSBs) from R0 or R1 T ALEH P3 AD[7:0] P4 EMIF READ DATA P4 T ALEL T RDS T RDH ALE P1.3 P1.3 T /RD P1.6 ACS T ACW T ACH P1.6 /WR P1.7 P1.7 Figure 13.7. Non-multiplexed 8-bit MOVX with Bank Select Timing Rev. 0.5 129 C8051F340/1/2/3/4/5/6/7 13.7.2. Multiplexed Mode 13.7.2.1.16-bit MOVX: EMI0CF[4:2] = `001', `010', or `011'. Muxed 16-bit WRITE ADDR[15:8] P3 EMIF ADDRESS (8 MSBs) from DPH EMIF ADDRESS (8 LSBs) from DPL T ALEH P3 AD[7:0] P4 EMIF WRITE DATA P4 T ALEL ALE P1.3 T T ACS WDS P1.3 T T ACW WDH ACH T /WR P1.7 P1.7 /RD P1.6 P1.6 Muxed 16-bit READ ADDR[15:8] P3 EMIF ADDRESS (8 MSBs) from DPH EMIF ADDRESS (8 LSBs) from DPL T ALEH P3 AD[7:0] P4 EMIF READ DATA P4 T ALEL T RDS T RDH ALE P1.3 P1.3 T /RD P1.6 ACS T ACW T ACH P1.6 /WR P1.7 P1.7 Figure 13.8. Multiplexed 16-bit MOVX Timing 130 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 13.7.2.2.8-bit MOVX without Bank Select: EMI0CF[4:2] = `001' or `011'. Muxed 8-bit WRITE Without Bank Select ADDR[15:8] EMIF ADDRESS (8 LSBs) from R0 or R1 T ALEH P3 AD[7:0] P4 EMIF WRITE DATA P4 T ALEL ALE P1.3 T T ACS WDS P1.3 T T ACW WDH ACH T /WR P1.7 P1.7 /RD P1.6 P1.6 Muxed 8-bit READ Without Bank Select ADDR[15:8] EMIF ADDRESS (8 LSBs) from R0 or R1 T ALEH P3 AD[7:0] P4 EMIF READ DATA P4 T ALEL T RDS T RDH ALE P1.3 P1.3 T /RD P1.6 ACS T ACW T ACH P1.6 /WR P1.7 P1.7 Figure 13.9. Multiplexed 8-bit MOVX without Bank Select Timing Rev. 0.5 131 C8051F340/1/2/3/4/5/6/7 13.7.2.3.8-bit MOVX with Bank Select: EMI0CF[4:2] = `010'. Muxed 8-bit WRITE with Bank Select ADDR[15:8] P3 EMIF ADDRESS (8 MSBs) from EMI0CN EMIF ADDRESS (8 LSBs) from R0 or R1 T ALEH P3 AD[7:0] P4 EMIF WRITE DATA P4 T ALEL ALE P1.3 T T ACS WDS P1.3 T T ACW WDH ACH T /WR P1.7 P1.7 /RD P1.6 P1.6 Muxed 8-bit READ with Bank Select ADDR[15:8] P3 EMIF ADDRESS (8 MSBs) from EMI0CN EMIF ADDRESS (8 LSBs) from R0 or R1 T ALEH P3 AD[7:0] P4 EMIF READ DATA P4 T ALEL T RDS T RDH ALE P1.3 P1.3 T /RD P1.6 ACS T ACW T ACH P1.6 /WR P1.7 P1.7 Figure 13.10. Multiplexed 8-bit MOVX with Bank Select Timing 132 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 13.1. AC Parameters for External Memory Interface Parameter TACS TACW TACH TALEH TALEL TWDS TWDH TRDS TRDH Description Address / Control Setup Time Address / Control Pulse Width Address / Control Hold Time Address Latch Enable High Time Address Latch Enable Low Time Write Data Setup Time Write Data Hold Time Read Data Setup Time Read Data Hold Time 0 1 x TSYSCLK 0 1 x TSYSCLK 1 x TSYSCLK 1 x TSYSCLK 0 20 0 Min* Max* 3 x TSYSCLK 16 x TSYSCLK 3 x TSYSCLK 4 x TSYSCLK 4 x TSYSCLK 19 x TSYSCLK 3 x TSYSCLK Units ns ns ns ns ns ns ns ns ns *Note: TSYSCLK is equal to one period of the device system clock (SYSCLK). Rev. 0.5 133 C8051F340/1/2/3/4/5/6/7 NOTES: 134 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 14. Oscillators C8051F340/1/2/3/4/5/6/7 devices include a programmable internal high-frequency oscillator, a programmable internal low-frequency oscillator (C8051F340/1/2/3/4/5), an external oscillator drive circuit, and a 4x Clock Multiplier. The internal high-frequency and low-frequency oscillators can be enabled/disabled and adjusted using the special function registers, as shown in Figure 14.1. The system clock (SYSCLK) can be derived from either of the internal oscillators, the external oscillator circuit, or the 4x Clock Multiplier divided by 2. The USB clock (USBCLK) can be derived from the internal oscillator, external oscillator, or 4x Clock Multiplier. Oscillator electrical specifications are given in Table 14.1. OSCICL OSCICN IOSCEN IFRDY SUSPEND IFCN1 IFCN0 OSCLCN OSCLEN OSCLRDY OSCLF3 OSCLF2 OSCLF1 OSCLF0 OSCLD1 OSCLD0 CLKSEL USBCLK2 USBCLK1 USBCLK0 CLKSL2 CLKSL1 CLKSL0 SYSCLK USBCLK USBCLK2-0 Option 2 VDD Option 3 XTAL2 XTAL2 EN Programmable HighFrequency Oscillator OSCLF3-0 EN Programmable LowFrequency Oscillator IOSC n n Option 1 XTAL1 10M XTAL2 (C8051F340/1/2/3/4/5) Input Circuit XTLVLD OSC EXOSC IOSC EXOSC EXOSC / 2 x2 x2 IOSC / 2 Clock Multiplier EXOSC Option 4 XTAL2 XTLVLD XOSCMD2 XOSCMD1 XOSCMD0 MULSEL1 MULSEL0 MULEN MULINIT MULRDY XFCN2 XFCN1 XFCN0 EXOSC / 2 EXOSC / 3 EXOSC / 4 OSCXCN CLKMUL Figure 14.1. Oscillator Diagram Rev. 0.5 135 C8051F340/1/2/3/4/5/6/7 14.1. Programmable Internal High-Frequency (H-F) Oscillator All C8051F340/1/2/3/4/5/6/7 devices include a programmable internal oscillator that defaults as the system clock after a system reset. The internal oscillator period can be programmed via the OSCICL register shown in SFR Definition 14.2. The OSCICL register is factory calibrated to obtain a 12 MHz internal oscillator frequency. Electrical specifications for the precision internal oscillator are given in Table 14.1 on page 145. Note that the system clock may be derived from the programmed internal oscillator divided by 1, 2, 4, or 8, as defined by the IFCN bits in register OSCICN. The divide value defaults to 8 following a reset. 14.1.1. Internal H-F Oscillator Suspend Mode The internal high-frequency oscillator may be placed in Suspend mode by writing `1' to the SUSPEND bit in register OSCICN. In Suspend mode, the internal H-F oscillator is stopped until a non-idle USB event is detected (Section 16) or VBUS matches the polarity selected by the VBPOL bit in register REG0CN (Section 8.2). Note that the USB transceiver can still detect USB events when it is disabled. SFR Definition 14.1. OSCICN: Internal H-F Oscillator Control R/W R R/W R R/W R/W R/W R/W Reset Value IOSCEN Bit7 IFRDY Bit6 SUSPEND Bit5 Bit4 Bit3 Bit2 IFCN1 Bit1 IFCN0 Bit0 10000000 SFR Address: 0xB2 IOSCEN: Internal H-F Oscillator Enable Bit. 0: Internal H-F Oscillator Disabled. 1: Internal H-F Oscillator Enabled. Bit6: IFRDY: Internal H-F Oscillator Frequency Ready Flag. 0: Internal H-F Oscillator is not running at programmed frequency. 1: Internal H-F Oscillator is running at programmed frequency. Bit5: SUSPEND: Force Suspend Writing a `1' to this bit will force the internal H-F oscillator to be stopped. The oscillator will be re-started on the next non-idle USB event (i.e., RESUME signaling) or VBUS interrupt event (see SFR Definition 8.1). Bits4-2: UNUSED. Read = 000b, Write = don't care. Bits1-0: IFCN1-0: Internal H-F Oscillator Frequency Control. 00: SYSCLK derived from Internal H-F Oscillator divided by 8. 01: SYSCLK derived from Internal H-F Oscillator divided by 4. 10: SYSCLK derived from Internal H-F Oscillator divided by 2. 11: SYSCLK derived from Internal H-F Oscillator divided by 1. Bit7: 136 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 14.2. OSCICL: Internal H-F Oscillator Calibration R/W R/W R/W R/W Bit4 R/W Bit3 R/W R/W Bit1 R/W Bit0 Reset Value Bit7 Bit6 Bit5 OSCCAL Bit2 Variable SFR Address: 0xB3 Bits4-0: OSCCAL: Oscillator Calibration Value These bits determine the internal H-F oscillator period. When set to 00000b, the oscillator operates at its fastest setting. When set to 11111b, the oscillator operates at is slowest setting. The contents of this register are factory calibrated to produce a 12 MHz internal oscillator frequency. Note: The contents of this register are undefined when Clock Recovery is enabled. See Section "16.4. USB Clock Configuration" on page 170 for details on Clock Recovery. 14.2. Programmable Internal Low-Frequency (L-F) Oscillator The C8051F340/1/2/3/4/5 devices include a programmable internal oscillator which operates at a nominal frequency of 80 kHz. The low-frequency oscillator circuit includes a divider that can be changed to divide the clock by 1, 2, 4, or 8, using the OSCLD bits in the OSCLCN register (see SFR Definition 14.3). Additionally, the OSCLF bits (OSCLCN5:2) can be used to adjust the oscillator's output frequency. 14.2.1. Calibrating the Internal L-F Oscillator Timers 2 and 3 include capture functions that can be used to capture the oscillator frequency, when running from a known time base. When either Timer 2 or Timer 3 is configured for L-F Oscillator Capture Mode, a falling edge (Timer 2) or rising edge (Timer 3) of the low-frequency oscillator's output will cause a capture event on the corresponding timer. As a capture event occurs, the current timer value (TMRnH:TMRnL) is copied into the timer reload registers (TMRnRLH:TMRnRLL). By recording the difference between two successive timer capture values, the low-frequency oscillator's period can be calculated. The OSCLF bits can then be adjusted to produce the desired oscillator period. Rev. 0.5 137 C8051F340/1/2/3/4/5/6/7 SFR Definition 14.3. OSCLCN: Internal L-F Oscillator Control R/W Bit7 R Bit6 R/W Bit5 R R/W R/W R/W R/W Reset Value OSCLEN OSCLRDY OSCLF3 OSCLF2 Bit4 OSCLF1 Bit3 OSCLF0 Bit2 OSCLD1 Bit1 OSCLD0 Bit0 00vvvv00 SFR Address: 0x86 OSCLEN: Internal L-F Oscillator Enable. 0: Internal L-F Oscillator Disabled. 1: Internal L-F Oscillator Enabled. Bit6: OSCLRDY: Internal L-F Oscillator Ready Flag. 0: Internal L-F Oscillator frequency not stabilized. 1: Internal L-F Oscillator frequency stabilized. Bits5-2: OSCLF[3:0]: Internal L-F Oscillator Frequency Control bits. Fine-tune control bits for the internal L-F Oscillator frequency. When set to 0000b, the L-F oscillator operates at its fastest setting. When set to 1111b, the L-F oscillator operates at its slowest setting. Bits1-0: OSCLD[1:0]: Internal L-F Oscillator Divider Select. 00: Divide by 8 selected. 01: Divide by 4selected. 10: Divide by 2 selected. 11: Divide by 1 selected. Bit7: 138 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 14.3. External Oscillator Drive Circuit The external oscillator circuit may drive an external crystal, ceramic resonator, capacitor, or RC network. A CMOS clock may also provide a clock input. For a crystal or ceramic resonator configuration, the crystal/ resonator must be wired across the XTAL1 and XTAL2 pins as shown in Option 1 of Figure 14.1. A 10 M resistor also must be wired across the XTAL1 and XTAL2 pins for the crystal/resonator configuration. In RC, capacitor, or CMOS clock configuration, the clock source should be wired to the XTAL2 pin as shown in Option 2, 3, or 4 of Figure 14.1. The type of external oscillator must be selected in the OSCXCN register, and the frequency control bits (XFCN) must be selected appropriately (see SFR Definition 14.4) Important Note on External Oscillator Usage: Port pins must be configured when using the external oscillator circuit. When the external oscillator drive circuit is enabled in crystal/resonator mode, Port pins P0.2 and P0.3 are used as XTAL1 and XTAL2 respectively. When the external oscillator drive circuit is enabled in capacitor, RC, or CMOS clock mode, Port pin P0.3 is used as XTAL2. The Port I/O Crossbar should be configured to skip the Port pins used by the oscillator circuit; see Section "15.1. Priority Crossbar Decoder" on page 149 for Crossbar configuration. Additionally, when using the external oscillator circuit in crystal/resonator, capacitor, or RC mode, the associated Port pins should be configured as analog inputs. In CMOS clock mode, the associated pin should be configured as a digital input. See Section "15.2. Port I/O Initialization" on page 151 for details on Port input mode selection. 14.3.1. Clocking Timers Directly Through the External Oscillator The external oscillator source divided by eight is a clock option for the timers (Section "21. Timers" on page 243) and the Programmable Counter Array (PCA) (Section "22. Programmable Counter Array (PCA0)" on page 263). When the external oscillator is used to clock these peripherals, but is not used as the system clock, the external oscillator frequency must be less than or equal to the system clock frequency. In this configuration, the clock supplied to the peripheral (external oscillator / 8) is synchronized with the system clock; the jitter associated with this synchronization is limited to 0.5 system clock cycles. 14.3.2. External Crystal Example If a crystal or ceramic resonator is used as an external oscillator source for the MCU, the circuit should be configured as shown in Figure 14.1, Option 1. The External Oscillator Frequency Control value (XFCN) should be chosen from the Crystal column of the table in SFR Definition 14.4 (OSCXCN register). For example, a 12 MHz crystal requires an XFCN setting of 111b. When the crystal oscillator is first enabled, the oscillator amplitude detection circuit requires a settling time to achieve proper bias. Introducing a delay of 1 ms between enabling the oscillator and checking the XTLVLD bit will prevent a premature switch to the external oscillator as the system clock. Switching to the external oscillator before the crystal oscillator has stabilized can result in unpredictable behavior. The recommended procedure is: Step 1. Step 2. Step 3. Step 4. Enable the external oscillator. Wait at least 1 ms. Poll for XTLVLD => `1'. Switch the system clock to the external oscillator. Important Note on External Crystals: Crystal oscillator circuits are quite sensitive to PCB layout. The crystal should be placed as close as possible to the XTAL pins on the device. The traces should be as short as possible and shielded with ground plane from any other traces which could introduce noise or interference. Rev. 0.5 139 C8051F340/1/2/3/4/5/6/7 14.3.3. External RC Example If an RC network is used as an external oscillator source for the MCU, the circuit should be configured as shown in Figure 14.1, Option 2. The capacitor should be no greater than 100 pF; however for very small capacitors, the total capacitance may be dominated by parasitic capacitance in the PCB layout. To determine the required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register, first select the RC network value to produce the desired frequency of oscillation. If the frequency desired is 100 kHz, let R = 246 k and C = 50 pF: 1.23 ( 10 )1.23 ( 10 ) f = ----------------------- = ------------------------- = 0.1 MHz = 100 kHz RC [ 246 x 50 ] Referring to the table in SFR Definition 14.4, the required XFCN setting is 010b. Programming XFCN to a higher setting in RC mode will improve frequency accuracy at an increased external oscillator supply current. 3 3 14.3.4. External Capacitor Example If a capacitor is used as an external oscillator for the MCU, the circuit should be configured as shown in Figure 14.1, Option 3. The capacitor should be no greater than 100 pF; however for very small capacitors, the total capacitance may be dominated by parasitic capacitance in the PCB layout. To determine the required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register, select the capacitor to be used and find the frequency of oscillation from the equations below. Assume VDD = 3.0 V and C = 50 pF: KF KF f = ------------------------- = ------------------------------( C x VDD ) ( 50 x 3 )MHz KF f = ---------------------150 MHz If a frequency of roughly 150 kHz is desired, select the K Factor from the table in SFR Definition 14.4 as KF = 22: 22f = -------- = 0.146 MHz, or 146 kHz 150 Therefore, the XFCN value to use in this example is 011b. 140 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 14.4. OSCXCN: External Oscillator Control R Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R R/W R/W R/W Reset Value XTLVLD XOSCMD2 XOSCMD1 XOSCMD0 Bit3 XFCN2 Bit2 XFCN1 Bit1 XFCN0 Bit0 00000000 SFR Address: 0xB1 Bit7: XTLVLD: Crystal Oscillator Valid Flag. (Read only when XOSCMD = 11x.) 0: Crystal Oscillator is unused or not yet stable. 1: Crystal Oscillator is running and stable. Bits6-4: XOSCMD2-0: External Oscillator Mode Bits. 00x: External Oscillator circuit off. 010: External CMOS Clock Mode. 011: External CMOS Clock Mode with divide by 2 stage. 100: RC Oscillator Mode. 101: Capacitor Oscillator Mode. 110: Crystal Oscillator Mode. 111: Crystal Oscillator Mode with divide by 2 stage. Bit3: RESERVED. Read = 0, Write = don't care. Bits2-0: XFCN2-0: External Oscillator Frequency Control Bits. 000-111: See table below: XFCN Crystal (XOSCMD = 11x) 000 f 32 kHz 001 32 kHz < f 84kHz 010 84 kHz < f 225 kHz 011 225 kHz < f 590 kHz 100 590 kHz < f 1.5 MHz 101 1.5 MHz < f 4 MHz 110 4 MHz < f 10 MHz 111 10 MHz < f 30 MHz RC (XOSCMD = 10x) f 25 kHz 25 kHz < f 50 kHz 50 kHz < f 100 kHz 100 kHz < f 200 kHz 200 kHz < f 400 kHz 400 kHz < f 800 kHz 800 kHz < f 1.6 MHz 1.6 MHz < f 3.2 MHz C (XOSCMD = 10x) K Factor = 0.87 K Factor = 2.6 K Factor = 7.7 K Factor = 22 K Factor = 65 K Factor = 180 K Factor = 664 K Factor = 1590 CRYSTAL MODE (Circuit from Figure 14.1, Option 1; XOSCMD = 11x) Choose XFCN value to match crystal or resonator frequency. RC MODE (Circuit from Figure 14.1, Option 2; XOSCMD = 10x) Choose XFCN value to match frequency range: f = 1.23(103) / (R x C), where f = frequency of clock in MHz C = capacitor value in pF R = Pull-up resistor value in k C MODE (Circuit from Figure 14.1, Option 3; XOSCMD = 10x) Choose K Factor (KF) for the oscillation frequency desired: f = KF / (C x VDD), where f = frequency of clock in MHz C = capacitor value the XTAL2 pin in pF VDD = Power Supply on MCU in volts Rev. 0.5 141 C8051F340/1/2/3/4/5/6/7 14.4. 4x Clock Multiplier The 4x Clock Multiplier allows a 12 MHz oscillator to generate the 48 MHz clock required for Full Speed USB communication (see Section "16.4. USB Clock Configuration" on page 170). A divided version of the Multiplier output can also be used as the system clock. See Section 14.5 for details on system clock and USB clock source selection. The 4x Clock Multiplier is configured via the CLKMUL register. The procedure for configuring and enabling the 4x Clock Multiplier is as follows: 1. 2. 3. 4. 5. 6. Reset the Multiplier by writing 0x00 to register CLKMUL. Select the Multiplier input source via the MULSEL bits. Enable the Multiplier with the MULEN bit (CLKMUL | = 0x80). Delay for >5 s. Initialize the Multiplier with the MULINIT bit (CLKMUL | = 0xC0). Poll for MULRDY => `1'. Important Note: When using an external oscillator as the input to the 4x Clock Multiplier, the external source must be enabled and stable before the Multiplier is initialized. See Section 14.5 for details on selecting an external oscillator source. SFR Definition 14.5. CLKMUL: Clock Multiplier Control R/W R/W Bit6 R Bit5 R/W R/W R/W R/W Bit1 R/W Bit0 Reset Value MULEN Bit7 MULINIT MULRDY Bit4 Bit3 Bit2 MULSEL 00000000 SFR Address 0xB9 MULEN: Clock Multiplier Enable 0: Clock Multiplier disabled. 1: Clock Multiplier enabled. Bit6: MULINIT: Clock Multiplier Initialize This bit should be a `0' when the Clock Multiplier is enabled. Once enabled, writing a `1' to this bit will initialize the Clock Multiplier. The MULRDY bit reads `1' when the Clock Multiplier is stabilized. Bit5: MULRDY: Clock Multiplier Ready This read-only bit indicates the status of the Clock Multiplier. 0: Clock Multiplier not ready. 1: Clock Multiplier ready (locked). Bits4-2: Unused. Read = 000b; Write = don't care. Bits1-0: MULSEL: Clock Multiplier Input Select These bits select the clock supplied to the Clock Multiplier. Bit7: MULSEL 00 01 10 11 Selected Clock Internal Oscillator External Oscillator External Oscillator / 2 RESERVED 142 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 14.5. System and USB Clock Selection The internal oscillator requires little start-up time and may be selected as the system or USB clock immediately following the OSCICN write that enables the internal oscillator. External crystals and ceramic resonators typically require a start-up time before they are settled and ready for use. The Crystal Valid Flag (XTLVLD in register OSCXCN) is set to `1' by hardware when the external oscillator is settled. To avoid reading a false XTLVLD, in crystal mode software should delay at least 1 ms between enabling the external oscillator and checking XTLVLD. RC and C modes typically require no startup time. 14.5.1. System Clock Selection The CLKSL[1:0] bits in register CLKSEL select which oscillator source is used as the system clock. CLKSL[1:0] must be set to 01b for the system clock to run from the external oscillator; however the external oscillator may still clock certain peripherals (timers, PCA, USB) when the internal oscillator is selected as the system clock. The system clock may be switched on-the-fly between the internal oscillator, external oscillator, and 4x Clock Multiplier so long as the selected oscillator is enabled and has settled. 14.5.2. USB Clock Selection The USBCLK[2:0] bits in register CLKSEL select which oscillator source is used as the USB clock. The USB clock may be derived from the 4x Clock Multiplier output, a divided version of the internal oscillator, or a divided version of the external oscillator. Note that the USB clock must be 48 MHz when operating USB0 as a Full Speed Function; the USB clock must be 6 MHz when operating USB0 as a Low Speed Function. See SFR Definition 14.6 for USB clock selection options. Some example USB clock configurations for Full and Low Speed mode are given below: Clock Signal USB Clock Clock Multiplier Input Internal Oscillator Clock Signal USB Clock Clock Multiplier Input External Oscillator Internal Oscillator Input Source Selection Clock Multiplier Internal Oscillator* Divide by 1 External Oscillator Input Source Selection Clock Multiplier External Oscillator Crystal Oscillator Mode 12 MHz Crystal Register Bit Settings USBCLK = 000b MULSEL = 00b IFCN = 11b Register Bit Settings USBCLK = 000b MULSEL = 01b XOSCMD = 110b XFCN = 111b *Note: Clock Recovery must be enabled for this configuration. Clock Signal USB Clock Internal Oscillator Clock Signal USB Clock External Oscillator Internal Oscillator Input Source Selection Internal Oscillator / 2 Divide by 1 External Oscillator Input Source Selection External Oscillator / 4 Crystal Oscillator Mode 24 MHz Crystal Register Bit Settings USBCLK = 001b IFCN = 11b Register Bit Settings USBCLK = 101b XOSCMD = 110b XFCN = 111b Rev. 0.5 143 C8051F340/1/2/3/4/5/6/7 SFR Definition 14.6. CLKSEL: Clock Select R/W R/W Bit6 R/W R/W Bit4 R/W R/W Bit2 R/W R/W Bit0 Reset Value Bit7 USBCLK Bit5 Bit3 CLKSL Bit1 00000000 SFR Address 0xA9 Bit 7: Unused. Read = 0b; Write = don't care. Bits6-4: USBCLK2-0: USB Clock Select These bits select the clock supplied to USB0. When operating USB0 in full-speed mode, the selected clock should be 48 MHz. When operating USB0 in low-speed mode, the selected clock should be 6 MHz. USBCLK 000 001 010 011 100 101 110 111 Selected Clock 4x Clock Multiplier Internal Oscillator / 2 External Oscillator External Oscillator / 2 External Oscillator / 3 External Oscillator / 4 RESERVED RESERVED Bit3: Unused. Read = 0b; Write = don't care. Bits2-0: CLKSL2-0: System Clock SelectThese bits select the system clock source. CLKSL 000 001 010 011* 100 101-111 Selected Clock Internal Oscillator (as determined by the IFCN bits in register OSCICN) External Oscillator 4x Clock Multiplier / 2 4x Clock Multiplier* Low-Frequency Oscillator RESERVED *Note: This option is only available on 48 MHz devices 144 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 14.1. Oscillator Electrical Characteristics VDD = 2.7 to 3.6 V; -40 to +85 C unless otherwise specified Parameter Conditions Oscillator Frequency Oscillator Supply Current (from VDD) Oscillator Frequency Oscillator Supply Current (from VDD) IFCN = 11b 24 C, VDD = 3.0 V, OSCICN.7 = 1 OSCLD = 11b 24 C, VDD = 3.0 V, OSCLCN.7 = 1 Full Speed Mode Low Speed Mode Min 11.82 -- Typ 12.00 685 Max 12.18 -- Units MHz A Internal High-Frequency Oscillator (Using Factory-Calibrated Settings) Internal Low-Frequency Oscillator (Using Factory-Calibrated Settings) 72 -- 80 7.0 99 -- kHz A External USB Clock Requirements USB Clock Frequency* 47.88 5.91 48 6 48.12 6.09 MHz *Note: Applies only to external oscillator sources. Rev. 0.5 145 C8051F340/1/2/3/4/5/6/7 NOTES: 146 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 15. Port Input/Output Digital and analog resources are available through 40 I/O pins (C8051F340/1/4/5) or 25 I/O pins (C8051F342/3/6/7). Port pins are organized as shown in Figure 15.1. Each of the Port pins can be defined as general-purpose I/O (GPIO) or analog input; Port pins P0.0-P3.7 can be assigned to one of the internal digital resources as shown in Figure 15.3. The designer has complete control over which functions are assigned, limited only by the number of physical I/O pins. This resource assignment flexibility is achieved through the use of a Priority Crossbar Decoder. Note that the state of a Port I/O pin can always be read in the corresponding Port latch, regardless of the Crossbar settings. The Crossbar assigns the selected internal digital resources to the I/O pins based on the Priority Decoder (Figure 15.3 and Figure 15.4). The registers XBR0, XBR1, and XBR2 defined in SFR Definition 15.1, SFR Definition 15.2, and SFR Definition 15.3, are used to select internal digital functions. All Port I/Os are 5 V tolerant (refer to Figure 15.2 for the Port cell circuit). The Port I/O cells are configured as either push-pull or open-drain in the Port Output Mode registers (PnMDOUT, where n = 0,1,2,3,4). Complete Electrical Specifications for Port I/O are given in Table 15.1 on page 162. XBR0, XBR1, XBR2, PnSKIP Registers PnMDOUT, PnMDIN Registers Priority Decoder Highest Priority UART0 SPI SMBus (Internal Digital Signals) CP0 Outputs CP1 Outputs SYSCLK 8 PCA T0, T1 Lowest Priority UART1* 6 2 8 2 8 P0 (P0.0-P0.7) 8 (Port Latches) P1 (P1.0-P1.7) 8 P2 (P2.0-P2.7) 8 P3 (P3.0-P3.7*) P3 I/O Cells P3.0 P3.7* P2 I/O Cells P2.0 P2.7 2 4 8 2 2 2 P0 I/O Cells P0.0 P0.7 P1.0 P1.7 Digital Crossbar 8 P1 I/O Cells *Note: P3.1-P3.7 and UART1 only available on 48-pin package Figure 15.1. Port I/O Functional Block Diagram (Port 0 through Port 3) Rev. 0.5 147 C8051F340/1/2/3/4/5/6/7 /WEAK-PULLUP PUSH-PULL /PORT-OUTENABLE VDD VDD (WEAK) PORT PAD PORT-OUTPUT Analog Select ANALOG INPUT PORT-INPUT GND Figure 15.2. Port I/O Cell Block Diagram 148 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 15.1. Priority Crossbar Decoder The Priority Crossbar Decoder (Figure 15.3) assigns a priority to each I/O function, starting at the top with UART0. When a digital resource is selected, the least-significant unassigned Port pin is assigned to that resource (excluding UART0, which is always at pins 4 and 5). If a Port pin is assigned, the Crossbar skips that pin when assigning the next selected resource. Additionally, the Crossbar will skip Port pins whose associated bits in the PnSKIP registers are set. The PnSKIP registers allow software to skip Port pins that are to be used for analog input, dedicated functions, or GPIO. Important Note on Crossbar Configuration: If a Port pin is claimed by a peripheral without use of the Crossbar, its corresponding PnSKIP bit should be set. This applies to the VREF signal, external oscillator pins (XTAL1, XTAL2), the ADC's external conversion start signal (CNVSTR), EMIF control signals, and any selected ADC or Comparator inputs. The PnSKIP registers may also be used to skip pins to be used as GPIO. The Crossbar skips selected pins as if they were already assigned, and moves to the next unassigned pin. Figure 15.3 shows the Crossbar Decoder priority with no Port pins skipped. Figure 15.4 shows a Crossbar example with pins P0.2 and P0.3 skipped (P0SKIP = 0x0C). P0 SF Signals (32-pin Package) SF Signals (48-pin Package) PIN I/O TX0 RX0 SCK MISO MOSI NSS* SDA SCL CP0 CP0A CP1 CP1A SYSCLK CEX0 CEX1 CEX2 CEX3 CEX4 ECI T0 T1 TX1** RX1** 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 3 4 5 CNVSTR XTAL1 XTAL2 VREF P1 P2 P3 P3.1-P3.7 Unavailable on 32-pin Package CNVSTR XTAL1 XTAL2 VREF ALE 6 7 0 1 2 3 4 5 6 /WR 7 0 /RD 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 *NSS is only pinned out in 4-wire SPI mode **UART1 Only in 48-pin Package 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P0SKIP[0:7] Port pin potentially available to peripheral P1SKIP[0:7] P2SKIP[0:7] P3SKIP[0:7] SF Signals Special Function Signals are not assigned by the Crossbar. When these signals are enabled, the Crossbar must be manually configured to skip their corresponding port pins. Figure 15.3. Crossbar Priority Decoder with No Pins Skipped Rev. 0.5 149 C8051F340/1/2/3/4/5/6/7 P0 SF Signals (32-pin Package) SF Signals (48-pin Package) PIN I/O TX0 RX0 SCK MISO MOSI NSS* SDA SCL CP0 CP0A CP1 CP1A SYSCLK CEX0 CEX1 CEX2 CEX3 CEX4 ECI T0 T1 TX1** RX1** 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P0SKIP[0:7] Port pin potentially available to peripheral SF Signals Special Function Signals are not assigned by the Crossbar. When these signals are enabled, the Crossbar must be manually configured to skip their corresponding port pins. P1SKIP[0:7] P2SKIP[0:7] P3SKIP[0:7] **UART1 Only in 48-pin Package *NSS is only pinned out in 4-wire SPI mode 0 1 2 3 4 5 CNVSTR XTAL1 XTAL2 VREF P1 P2 P3 P3.1-P3.7 Unavailable on 32-pin Package CNVSTR XTAL1 XTAL2 VREF ALE 6 7 0 1 2 3 4 5 6 /WR 7 0 /RD 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 Figure 15.4. Crossbar Priority Decoder with Crystal Pins Skipped Registers XBR0, XBR1, and XBR2 are used to assign the digital I/O resources to the physical I/O Port pins. Note that when the SMBus is selected, the Crossbar assigns both pins associated with the SMBus (SDA and SCL); when either UART is selected, the Crossbar assigns both pins associated with the UART (TX and RX). UART0 pin assignments are fixed for bootloading purposes: UART TX0 is always assigned to P0.4; UART RX0 is always assigned to P0.5. Standard Port I/Os appear contiguously after the prioritized functions have been assigned. Important Note: The SPI can be operated in either 3-wire or 4-wire modes, depending on the state of the NSSMD1-NSSMD0 bits in register SPI0CN. According to the SPI mode, the NSS signal may or may not be routed to a Port pin. 150 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 15.2. Port I/O Initialization Port I/O initialization consists of the following steps: Step 1. Select the input mode (analog or digital) for all Port pins, using the Port Input Mode register (PnMDIN). Step 2. Select the output mode (open-drain or push-pull) for all Port pins, using the Port Output Mode register (PnMDOUT). Step 3. Select any pins to be skipped by the I/O Crossbar using the Port Skip registers (PnSKIP). Step 4. Assign Port pins to desired peripherals (XBR0, XBR1). Step 5. Enable the Crossbar (XBARE = `1'). All Port pins must be configured as either analog or digital inputs. Any pins to be used as Comparator or ADC inputs should be configured as an analog inputs. When a pin is configured as an analog input, its weak pull-up, digital driver, and digital receiver are disabled. This process saves power and reduces noise on the analog input. Pins configured as digital inputs may still be used by analog peripherals; however this practice is not recommended. To configure a Port pin for digital input, write `0' to the corresponding bit in register PnMDOUT, and write `1' to the corresponding Port latch (register Pn). Additionally, all analog input pins should be configured to be skipped by the Crossbar (accomplished by setting the associated bits in PnSKIP). Port input mode is set in the PnMDIN register, where a `1' indicates a digital input, and a `0' indicates an analog input. All pins default to digital inputs on reset. The output driver characteristics of the I/O pins are defined using the Port Output Mode registers (PnMDOUT). Each Port Output driver can be configured as either open drain or push-pull. This selection is required even for the digital resources selected in the XBRn registers, and is not automatic. The only exception to this is the SMBus (SDA, SCL) pins, which are configured as open-drain regardless of the PnMDOUT settings. When the WEAKPUD bit in XBR1 is `0', a weak pull-up is enabled for all Port I/O configured as open-drain. WEAKPUD does not affect the push-pull Port I/O. Furthermore, the weak pull-up is turned off on an output that is driving a `0' to avoid unnecessary power dissipation. Registers XBR0 and XBR1 must be loaded with the appropriate values to select the digital I/O functions required by the design. Setting the XBARE bit in XBR1 to `1' enables the Crossbar. Until the Crossbar is enabled, the external pins remain as standard Port I/O (in input mode), regardless of the XBRn Register settings. For given XBRn Register settings, one can determine the I/O pin-out using the Priority Decode Table; as an alternative, the Configuration Wizard utility of the Silicon Labs IDE software will determine the Port I/O pin-assignments based on the XBRn Register settings. Important Note: The Crossbar must be enabled to use Ports P0, P1, P2, and P3 as standard Port I/O in output mode. These Port output drivers are disabled while the Crossbar is disabled. Port 4 always functions as standard GPIO. Rev. 0.5 151 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.1. XBR0: Port I/O Crossbar Register 0 R/W R/W R/W R/W R/W R/W R/W R/W Reset Value CP1AE Bit7 CP1E Bit6 CP0AE Bit5 CP0E Bit4 SYSCKE Bit3 SMB0E Bit2 SPI0E Bit1 URT0E Bit0 00000000 SFR Address: 0xE1 Bit7: CP1AE: Comparator1 Asynchronous Output Enable 0: Asynchronous CP1 unavailable at Port pin. 1: Asynchronous CP1 routed to Port pin. CP1E: Comparator1 Output Enable 0: CP1 unavailable at Port pin. 1: CP1 routed to Port pin. CP0AE: Comparator0 Asynchronous Output Enable 0: Asynchronous CP0 unavailable at Port pin. 1: Asynchronous CP0 routed to Port pin. CP0E: Comparator0 Output Enable 0: CP0 unavailable at Port pin. 1: CP0 routed to Port pin. SYSCKE: /SYSCLK Output Enable 0: /SYSCLK unavailable at Port pin. 1: /SYSCLK output routed to Port pin. SMB0E: SMBus I/O Enable 0: SMBus I/O unavailable at Port pins. 1: SMBus I/O routed to Port pins. SPI0E: SPI I/O Enable 0: SPI I/O unavailable at Port pins. 1: SPI I/O routed to Port pins. URT0E: UART0 I/O Output Enable 0: UART0 I/O unavailable at Port pins. 1: UART0 TX0, RX0 routed to Port pins P0.4 and P0.5. Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: 152 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.2. XBR1: Port I/O Crossbar Register 1 R/W R/W R/W R/W R/W R/W Bit2 R/W R/W Bit0 Reset Value WEAKPUD Bit7 XBARE Bit6 T1E Bit5 T0E Bit4 ECIE Bit3 PCA0ME Bit1 00000000 SFR Address: 0xE2 WEAKPUD: Port I/O Weak Pull-up Disable. 0: Weak Pull-ups enabled (except for Ports whose I/O are configured as analog input or push-pull output). 1: Weak Pull-ups disabled. Bit6: XBARE: Crossbar Enable. 0: Crossbar disabled; all Port drivers disabled. 1: Crossbar enabled. Bit5: T1E: T1 Enable 0: T1 unavailable at Port pin. 1: T1 routed to Port pin. Bit4: T0E: T0 Enable 0: T0 unavailable at Port pin. 1: T0 routed to Port pin. Bit3: ECIE: PCA0 External Counter Input Enable 0: ECI unavailable at Port pin. 1: ECI routed to Port pin. Bits2-0: PCA0ME: PCA Module I/O Enable Bits. 000: All PCA I/O unavailable at Port pins. 001: CEX0 routed to Port pin. 010: CEX0, CEX1 routed to Port pins. 011: CEX0, CEX1, CEX2 routed to Port pins. 100: CEX0, CEX1, CEX2, CEX3 routed to Port pins. 101: CEX0, CEX1, CEX2, CEX3, CEX4 routed to Port pins. 110: Reserved. 111: Reserved. Bit7: SFR Definition 15.3. XBR2: Port I/O Crossbar Register 2 R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Reset Value URT1E Bit0 00000000 SFR Address: 0xE3 Bits7-1: RESERVED: Always write to 0000000b Bit0: URT1E: UART1 I/O Output Enable (C8051F340/1/4/5 Only) 0: UART1 I/O unavailable at Port pins. 1: UART1 TX1, RX1 routed to Port pins. Rev. 0.5 153 C8051F340/1/2/3/4/5/6/7 15.3. General Purpose Port I/O Port pins that remain unassigned by the Crossbar and are not used by analog peripherals can be used for general purpose I/O. Ports 3-0 are accessed through corresponding special function registers (SFRs) that are both byte addressable and bit addressable. Port 4 (C8051F340/1/4/5 only) uses an SFR which is byte-addressable. When writing to a Port, the value written to the SFR is latched to maintain the output data value at each pin. When reading, the logic levels of the Port's input pins are returned regardless of the XBRn settings (i.e., even when the pin is assigned to another signal by the Crossbar, the Port register can always read its corresponding Port I/O pin). The exception to this is the execution of the read-modify-write instructions. The read-modify-write instructions when operating on a Port SFR are the following: ANL, ORL, XRL, JBC, CPL, INC, DEC, DJNZ and MOV, CLR or SETB, when the destination is an individual bit in a Port SFR. For these instructions, the value of the register (not the pin) is read, modified, and written back to the SFR. SFR Definition 15.4. P0: Port0 Latch R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P0.7 Bit7 P0.6 Bit6 P0.5 Bit5 P0.4 Bit4 P0.3 Bit3 P0.2 Bit2 P0.1 Bit1 P0.0 Bit0 (bit addressable) 11111111 SFR Address: 0x80 Bits7-0: P0.[7:0] Write - Output appears on I/O pins per Crossbar Registers (when XBARE = `1'). 0: Logic Low Output. 1: Logic High Output (high impedance if corresponding P0MDOUT.n bit = 0). Read - Always reads `0' if selected as analog input in register P0MDIN. Directly reads Port pin when configured as digital input. 0: P0.n pin is logic low. 1: P0.n pin is logic high. SFR Definition 15.5. P0MDIN: Port0 Input Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 11111111 SFR Address: 0xF1 Bits7-0: Analog Input Configuration Bits for P0.7-P0.0 (respectively). Port pins configured as analog inputs have their weak pull-up, digital driver, and digital receiver disabled. 0: Corresponding P0.n pin is configured as an analog input. 1: Corresponding P0.n pin is not configured as an analog input. 154 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.6. P0MDOUT: Port0 Output Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xA4 Bits7-0: Output Configuration Bits for P0.7-P0.0 (respectively): ignored if corresponding bit in register P0MDIN is logic 0. 0: Corresponding P0.n Output is open-drain. 1: Corresponding P0.n Output is push-pull. (Note: When SDA and SCL appear on any of the Port I/O, each are open-drain regardless of the value of P0MDOUT). SFR Definition 15.7. P0SKIP: Port0 Skip R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xD4 Bits7-0: P0SKIP[7:0]: Port0 Crossbar Skip Enable Bits. These bits select Port pins to be skipped by the Crossbar Decoder. Port pins used as analog inputs (for ADC or Comparator) or used as special functions (VREF input, external oscillator circuit, CNVSTR input) should be skipped by the Crossbar. 0: Corresponding P0.n pin is not skipped by the Crossbar. 1: Corresponding P0.n pin is skipped by the Crossbar. Rev. 0.5 155 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.8. P1: Port1 Latch R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P1.7 Bit7 P1.6 Bit6 P1.5 Bit5 P1.4 Bit4 P1.3 Bit3 P1.2 Bit2 P1.1 Bit1 P1.0 Bit0 (bit addressable) 11111111 SFR Address: 0x90 Bits7-0: P1.[7:0] Write - Output appears on I/O pins per Crossbar Registers (when XBARE = `1'). 0: Logic Low Output. 1: Logic High Output (high impedance if corresponding P1MDOUT.n bit = 0). Read - Always reads `0' if selected as analog input in register P1MDIN. Directly reads Port pin when configured as digital input. 0: P1.n pin is logic low. 1: P1.n pin is logic high. SFR Definition 15.9. P1MDIN: Port1 Input Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 11111111 SFR Address: 0xF2 Bits7-0: Analog Input Configuration Bits for P1.7-P1.0 (respectively). Port pins configured as analog inputs have their weak pull-up, digital driver, and digital receiver disabled. 0: Corresponding P1.n pin is configured as an analog input. 1: Corresponding P1.n pin is not configured as an analog input. SFR Definition 15.10. P1MDOUT: Port1 Output Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xA5 Bits7-0: Output Configuration Bits for P1.7-P1.0 (respectively): ignored if corresponding bit in register P1MDIN is logic 0. 0: Corresponding P1.n Output is open-drain. 1: Corresponding P1.n Output is push-pull. 156 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.11. P1SKIP: Port1 Skip R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xD5 Bits7-0: P1SKIP[7:0]: Port1 Crossbar Skip Enable Bits. These bits select Port pins to be skipped by the Crossbar Decoder. Port pins used as analog inputs (for ADC or Comparator) or used as special functions (VREF input, external oscillator circuit, CNVSTR input) should be skipped by the Crossbar. 0: Corresponding P1.n pin is not skipped by the Crossbar. 1: Corresponding P1.n pin is skipped by the Crossbar. SFR Definition 15.12. P2: Port2 Latch R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P2.7 Bit7 P2.6 Bit6 P2.5 Bit5 P2.4 Bit4 P2.3 Bit3 P2.2 Bit2 P2.1 Bit1 P2.0 Bit0 (bit addressable) 11111111 SFR Address: 0xA0 Bits7-0: P2.[7:0] Write - Output appears on I/O pins per Crossbar Registers (when XBARE = `1'). 0: Logic Low Output. 1: Logic High Output (high impedance if corresponding P2MDOUT.n bit = 0). Read - Always reads `0' if selected as analog input in register P2MDIN. Directly reads Port pin when configured as digital input. 0: P2.n pin is logic low. 1: P2.n pin is logic high. SFR Definition 15.13. P2MDIN: Port2 Input Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 11111111 SFR Address: 0xF3 Bits7-0: Analog Input Configuration Bits for P2.7-P2.0 (respectively). Port pins configured as analog inputs have their weak pull-up, digital driver, and digital receiver disabled. 0: Corresponding P2.n pin is configured as an analog input. 1: Corresponding P2.n pin is not configured as an analog input. Rev. 0.5 157 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.14. P2MDOUT: Port2 Output Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xA6 Bits7-0: Output Configuration Bits for P2.7-P2.0 (respectively): ignored if corresponding bit in register P2MDIN is logic 0. 0: Corresponding P2.n Output is open-drain. 1: Corresponding P2.n Output is push-pull. SFR Definition 15.15. P2SKIP: Port2 Skip R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xD6 Bits7-0: P2SKIP[7:0]: Port2 Crossbar Skip Enable Bits. These bits select Port pins to be skipped by the Crossbar Decoder. Port pins used as analog inputs (for ADC or Comparator) or used as special functions (VREF input, external oscillator circuit, CNVSTR input) should be skipped by the Crossbar. 0: Corresponding P2.n pin is not skipped by the Crossbar. 1: Corresponding P2.n pin is skipped by the Crossbar. 158 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.16. P3: Port3 Latch R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P3.7 Bit7 P3.6 Bit6 P3.5 Bit5 P3.4 Bit4 P3.3 Bit3 P3.2 Bit2 P3.1 Bit1 P3.0 Bit0 (bit addressable) 11111111 SFR Address: 0xB0 Bits7-0: P3.[7:0] Write - Output appears on I/O pins. 0: Logic Low Output. 1: Logic High Output (high impedance if corresponding P3MDOUT.n bit = 0). Read - Always reads `0' if selected as analog input in register P3MDIN. Directly reads Port pin when configured as digital input. 0: P3.n pin is logic low. 1: P3.n pin is logic high. Note: P3.1-3.7 are only available on 48-pin devices. SFR Definition 15.17. P3MDIN: Port3 Input Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 11111111 SFR Address: 0xF4 Bits7-0: Analog Input Configuration Bits for P3.7-P3.0 (respectively). Port pins configured as analog inputs have their weak pull-up, digital driver, and digital receiver disabled. 0: Corresponding P3.n pin is configured as an analog input. 1: Corresponding P3.n pin is not configured as an analog input. Note: P3.1-3.7 are only available on 48-pin devices. SFR Definition 15.18. P3MDOUT: Port3 Output Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xA7 Bits7-0: Output Configuration Bits for P3.7-P3.0 (respectively); ignored if corresponding bit in register P3MDIN is logic 0. 0: Corresponding P3.n Output is open-drain. 1: Corresponding P3.n Output is push-pull. Note: P3.1-3.7 are only available on 48-pin devices. Rev. 0.5 159 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.19. P3SKIP: Port3 Skip R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xDF Bits7-0: P3SKIP[3:0]: Port3 Crossbar Skip Enable Bits. These bits select Port pins to be skipped by the Crossbar Decoder. Port pins used as analog inputs (for ADC or Comparator) or used as special functions (VREF input, external oscillator circuit, CNVSTR input) should be skipped by the Crossbar. 0: Corresponding P3.n pin is not skipped by the Crossbar. 1: Corresponding P3.n pin is skipped by the Crossbar. Note: P3.1-3.7 are only available on 48-pin devices. SFR Definition 15.20. P4: Port4 Latch R/W R/W R/W R/W R/W R/W R/W R/W Reset Value P4.7 Bit7 P4.6 Bit6 P4.5 Bit5 P4.4 Bit4 P4.3 Bit3 P4.2 Bit2 P4.1 Bit1 P4.0 Bit0 11111111 SFR Address: 0xC7 Bits7-0: P4.[7:0] Write - Output appears on I/O pins. 0: Logic Low Output. 1: Logic High Output (high impedance if corresponding P4MDOUT.n bit = 0). Read - Always reads `0' if selected as analog input in register P4MDIN. Directly reads Port pin when configured as digital input. 0: P4.n pin is logic low. 1: P4.n pin is logic high. Note: P4 is only available on 48-pin devices. 160 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 15.21. P4MDIN: Port4 Input Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 11111111 SFR Address: 0xF5 Bits7-0: Analog Input Configuration Bits for P4.7-P4.0 (respectively). Port pins configured as analog inputs have their weak pull-up, digital driver, and digital receiver disabled. 0: Corresponding P4.n pin is configured as an analog input. 1: Corresponding P4.n pin is not configured as an analog input. Note: P4 is only available on 48-pin devices. SFR Definition 15.22. P4MDOUT: Port4 Output Mode R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xAE Bits7-0: Output Configuration Bits for P4.7-P4.0 (respectively); ignored if corresponding bit in register P4MDIN is logic 0. 0: Corresponding P4.n Output is open-drain. 1: Corresponding P4.n Output is push-pull. Note: P4 is only available on 48-pin devices. Rev. 0.5 161 C8051F340/1/2/3/4/5/6/7 Table 15.1. Port I/O DC Electrical Characteristics VDD = 2.7 to 3.6 V, -40 to +85 C unless otherwise specified Parameters Conditions Min IOH = -3 mA, Port I/O push-pull VDD - 0.7 Output High Voltage IOH = -10 A, Port I/O push-pull IOH = -10 mA, Port I/O push-pull IOL = 8.5 mA Output Low Voltage Input High Voltage Input Low Voltage Input Leakage Current Weak Pull-up Off Weak Pull-up On, VIN = 0 V 25 IOL = 10 A IOL = 25 mA 2.0 0.8 1 50 1.0 V V A VDD - 0.1 VDD - 0.8 0.6 0.1 V Typ Max Units V 162 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 16. Universal Serial Bus Controller (USB0) C8051F340/1/2/3/4/5/6/7 devices include a complete Full/Low Speed USB function for USB peripheral implementations*. The USB Function Controller (USB0) consists of a Serial Interface Engine (SIE), USB Transceiver (including matching resistors and configurable pull-up resistors), 1k FIFO block, and clock recovery mechanism for crystal-less operation. No external components are required. The USB Function Controller and Transceiver is Universal Serial Bus Specification 2.0 compliant. Transceiver Serial Interface Engine (SIE) Endpoint0 VDD D+ Data Transfer Control DIN/OUT USB Control, Status, and Interrupt Registers CIP-51 Core Endpoint1 Endpoint2 IN IN IN Endpoint3 OUT OUT OUT USB FIFOs (1k RAM) Figure 16.1. USB0 Block Diagram Important Note: This document assumes a comprehensive understanding of the USB Protocol. Terms and abbreviations used in this document are defined in the USB Specification. We encourage you to review the latest version of the USB Specification before proceeding. *Note: The C8051F340/1/2/3/4/5/6/7 cannot be used as a USB Host device. Rev. 0.5 163 C8051F340/1/2/3/4/5/6/7 16.1. Endpoint Addressing A total of eight endpoint pipes are available. The control endpoint (Endpoint0) always functions as a bi-directional IN/OUT endpoint. The other endpoints are implemented as three pairs of IN/OUT endpoint pipes: Table 16.1. Endpoint Addressing Scheme Endpoint Endpoint0 Endpoint1 Endpoint2 Endpoint3 Associated Pipes Endpoint0 IN Endpoint0 OUT Endpoint1 IN Endpoint1 OUT Endpoint2 IN Endpoint2 OUT Endpoint3 IN Endpoint3 OUT USB Protocol Address 0x00 0x00 0x81 0x01 0x82 0x02 0x83 0x03 16.2. USB Transceiver The USB Transceiver is configured via the USB0XCN register shown in SFR Definition 16.1. This configuration includes Transceiver enable/disable, pull-up resistor enable/disable, and device speed selection (Full or Low Speed). When bit SPEED = `1', USB0 operates as a Full Speed USB function, and the on-chip pull-up resistor (if enabled) appears on the D+ pin. When bit SPEED = `0', USB0 operates as a Low Speed USB function, and the on-chip pull-up resistor (if enabled) appears on the D- pin. Bits4-0 of register USB0XCN can be used for Transceiver testing as described in SFR Definition 16.1. The pull-up resistor is enabled only when VBUS is present (see Section "8.2. VBUS Detection" on page 69 for details on VBUS detection). Important Note: The USB clock should be active before the Transceiver is enabled. 164 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 16.1. USB0XCN: USB0 Transceiver Control R/W R/W R/W R/W Bit4 R/W Bit3 R R R Reset Value PREN Bit7 PHYEN Bit6 SPEED Bit5 PHYTST1 PHYTST0 DFREC Bit2 Dp Bit1 Dn Bit0 00000000 SFR Address: 0xD7 Bit7: PREN: Internal Pull-up Resistor Enable The location of the pull-up resistor (D+ or D-) is determined by the SPEED bit. 0: Internal pull-up resistor disabled (device effectively detached from the USB network). 1: Internal pull-up resistor enabled when VBUS is present (device attached to the USB network). Bit6: PHYEN: Physical Layer Enable This bit enables/disables the USB0 physical layer transceiver. 0: Transceiver disabled (suspend). 1: Transceiver enabled (normal). Bit5: SPEED: USB0 Speed Select This bit selects the USB0 speed. 0: USB0 operates as a Low Speed device. If enabled, the internal pull-up resistor appears on the D- line. 1: USB0 operates as a Full Speed device. If enabled, the internal pull-up resistor appears on the D+ line. Bits4-3: PHYTST1-0: Physical Layer Test These bits can be used to test the USB0 transceiver. PHYTST[1:0] 00b 01b 10b 11b Bit2: Mode Mode 0: Normal (non-test mode) Mode 1: Differential `1' Forced Mode 2: Differential `0' Forced Mode 3: Single-Ended `0' Forced D+ X 1 0 0 D- X 0 1 0 Bit1: Bit0: DFREC: Differential Receiver The state of this bit indicates the current differential value present on the D+ and D- lines when PHYEN = `1'. 0: Differential `0' signaling on the bus. 1: Differential `1' signaling on the bus. Dp: D+ Signal Status This bit indicates the current logic level of the D+ pin. 0: D+ signal currently at logic 0. 1: D+ signal currently at logic 1. Dn: D- Signal Status This bit indicates the current logic level of the D- pin. 0: D- signal currently at logic 0. 1: D- signal currently at logic 1. Rev. 0.5 165 C8051F340/1/2/3/4/5/6/7 16.3. USB Register Access The USB0 controller registers listed in Table 16.2 are accessed through two SFRs: USB0 Address (USB0ADR) and USB0 Data (USB0DAT). The USB0ADR register selects which USB register is targeted by reads/writes of the USB0DAT register. See Figure 16.2. Endpoint control/status registers are accessed by first writing the USB register INDEX with the target endpoint number. Once the target endpoint number is written to the INDEX register, the control/status registers associated with the target endpoint may be accessed. See the "Indexed Registers" section of Table 16.2 for a list of endpoint control/status registers. Important Note: The USB clock must be active when accessing USB registers. 8051 SFRs USB Controller Interrupt Registers FIFO Access Common Registers USB0DAT Index Register Endpoint0 Control/ Status Registers Endpoint1 Control/ Status Registers Endpoint2 Control/ Status Registers USB0ADR Endpoint3 Control/ Status Registers Figure 16.2. USB0 Register Access Scheme 166 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 16.2. USB0ADR: USB0 Indirect Address R/W R/W R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value BUSY Bit7 AUTORD Bit6 USBADDR 00000000 SFR Address: 0x96 Bits7: BUSY: USB0 Register Read Busy Flag This bit is used during indirect USB0 register accesses. Software should write `1' to this bit to initiate a read of the USB0 register targeted by the USBADDR bits (USB0ADR.[5-0]). The target address and BUSY bit may be written in the same write to USB0ADR. After BUSY is set to `1', hardware will clear BUSY when the targeted register data is ready in the USB0DAT register. Software should check BUSY for `0' before writing to USB0DAT. Write: 0: No effect. 1: A USB0 indirect register read is initiated at the address specified by the USBADDR bits. Read: 0: USB0DAT register data is valid. 1: USB0 is busy accessing an indirect register; USB0DAT register data is invalid. Bit6: AUTORD: USB0 Register Auto-read Flag This bit is used for block FIFO reads. 0: BUSY must be written manually for each USB0 indirect register read. 1: The next indirect register read will automatically be initiated when software reads USB0DAT (USBADDR bits will not be changed). Bits5-0: USBADDR: USB0 Indirect Register Address These bits hold a 6-bit address used to indirectly access the USB0 core registers. Table 16.2 lists the USB0 core registers and their indirect addresses. Reads and writes to USB0DAT will target the register indicated by the USBADDR bits. Rev. 0.5 167 C8051F340/1/2/3/4/5/6/7 SFR Definition 16.3. USB0DAT: USB0 Data R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value USB0DAT 00000000 SFR Address: 0x97 This SFR is used to indirectly read and write USB0 registers. Write Procedure: 1. Poll for BUSY (USB 0ADR.7) => `0'. 2. Load the target USB0 register address into the USBADDR bits in register USB0ADR. 3. Write data to USB0DAT. 4. Repeat (Step 2 may be skipped when writing to the same USB0 register). Read Procedure: 1. Poll for BUSY (USB 0ADR.7) => `0'. 2. Load the target USB0 register address into the USBADDR bits in register USB0ADR. 3. Write `1' to the BUSY bit in register USB0ADR (steps 2 and 3 can be performed in the same write). 4. Poll for BUSY (USB 0ADR.7) => `0'. 5. Read data from USB0DAT. 6. Repeat from Step 2 (Step 2 may be skipped when reading the same USB0 register; Step 3 may be skipped when the AUTORD bit (USB0ADR.6) is logic 1). 168 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 16.2. USB0 Controller Registers USB Register Name IN1INT OUT1INT CMINT IN1IE OUT1IE CMIE FADDR POWER FRAMEL FRAMEH INDEX CLKREC FIFOn E0CSR EINCSRL EINCSRH EOUTCSRL EOUTCSRH E0CNT EOUTCNTL EOUTCNTH USB Register Address 0x02 0x04 0x06 0x07 0x09 0x0B 0x00 0x01 0x0C 0x0D 0x0E 0x0F 0x20-0x23 0x11 0x12 0x14 0x15 0x16 0x17 Description Interrupt Registers Endpoint0 and Endpoints1-3 IN Interrupt Flags Endpoints1-3 OUT Interrupt Flags Common USB Interrupt Flags Endpoint0 and Endpoints1-3 IN Interrupt Enables Endpoints1-3 OUT Interrupt Enables Common USB Interrupt Enables Common Registers Function Address Power Management Frame Number Low Byte Frame Number High Byte Endpoint Index Selection Clock Recovery Control Endpoints0-3 FIFOs Indexed Registers Endpoint0 Control / Status Endpoint IN Control / Status Low Byte Endpoint IN Control / Status High Byte Endpoint OUT Control / Status Low Byte Endpoint OUT Control / Status High Byte Number of Received Bytes in Endpoint0 FIFO Endpoint OUT Packet Count Low Byte Endpoint OUT Packet Count High Byte Page Number 177 177 178 179 179 180 173 175 176 176 169 170 172 183 186 187 189 190 184 190 190 USB Register Definition 16.4. INDEX: USB0 Endpoint Index R R R R R/W Bit3 R/W R/W R/W Bit0 Reset Value Bit7 Bit6 Bit5 Bit4 Bit2 EPSEL Bit1 00000000 USB Address: 0x0E Bits7-4: Unused. Read = 0000b; Write = don't care. Bits3-0: EPSEL: Endpoint Select These bits select which endpoint is targeted when indexed USB0 registers are accessed. INDEX 0x0 0x1 0x2 0x3 0x4-0xF Target Endpoint 0 1 2 3 Reserved Rev. 0.5 169 C8051F340/1/2/3/4/5/6/7 16.4. USB Clock Configuration USB0 is capable of communication as a Full or Low Speed USB function. Communication speed is selected via the SPEED bit in SFR USB0XCN. When operating as a Low Speed function, the USB0 clock must be 6 MHz. When operating as a Full Speed function, the USB0 clock must be 48 MHz. Clock options are described in Section "14. Oscillators" on page 135. The USB0 clock is selected via SFR CLKSEL (see SFR Definition 14.6). Clock Recovery circuitry uses the incoming USB data stream to adjust the internal oscillator; this allows the internal oscillator (and 4x Clock Multiplier) to meet the requirements for USB clock tolerance. Clock Recovery should be used in the following configurations: Communication Speed Full Speed Low Speed USB Clock 4x Clock Multiplier Internal Oscillator / 2 4x Clock Multiplier Input Internal Oscillator N/A When operating USB0 as a Low Speed function with Clock Recovery, software must write `1' to the CRLOW bit to enable Low Speed Clock Recovery. Clock Recovery is typically not necessary in Low Speed mode. Single Step Mode can be used to help the Clock Recovery circuitry to lock when high noise levels are present on the USB network. This mode is not required (or recommended) in typical USB environments. USB Register Definition 16.5. CLKREC: Clock Recovery Control R/W R/W R/W R/W Bit4 R/W Bit3 R/W R/W Bit1 R/W Bit0 Reset Value CRE Bit7 CRSSEN Bit6 CRLOW Bit5 Reserved Bit2 00001001 USB Address: 0x0F CRE: Clock Recovery Enable. This bit enables/disables the USB clock recovery feature. 0: Clock recovery disabled. 1: Clock recovery enabled. Bit6: CRSSEN: Clock Recovery Single Step. This bit forces the oscillator calibration into `single-step' mode during clock recovery. 0: Normal calibration mode. 1: Single step mode. Bit5: CRLOW: Low Speed Clock Recovery Mode. This bit must be set to `1' if clock recovery is used when operating as a Low Speed USB device. 0: Full Speed Mode. 1: Low Speed Mode. Bits4-0: Reserved. Read = Variable. Must Write = 01001b. Bit7: Note: The USB transceiver must be enabled before enabling Clock Recovery. 170 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 16.5. FIFO Management 1024 bytes of on-chip XRAM are used as FIFO space for USB0. This FIFO space is split between Endpoints0-3 as shown in Figure 16.3. FIFO space allocated for Endpoints1-3 is configurable as IN, OUT, or both (Split Mode: half IN, half OUT). 0x07FF Endpoint0 (64 bytes) 0x07C0 0x07BF Endpoint1 (128 bytes) 0x0740 0x073F Endpoint2 (256 bytes) 0x0640 0x063F Configurable as IN, OUT, or both (Split Mode) Endpoint3 (512 bytes) 0x0440 0x043F Free (64 bytes) 0x0400 USB Clock Domain System Clock Domain 0x03FF User XRAM (1024 bytes) 0x0000 Figure 16.3. USB FIFO Allocation 16.5.1. FIFO Split Mode The FIFO space for Endpoints1-3 can be split such that the upper half of the FIFO space is used by the IN endpoint, and the lower half is used by the OUT endpoint. For example: if the Endpoint3 FIFO is configured for Split Mode, the upper 256 bytes (0x0540 to 0x063F) are used by Endpoint3 IN and the lower 256 bytes (0x0440 to 0x053F) are used by Endpoint3 OUT. If an endpoint FIFO is not configured for Split Mode, that endpoint IN/OUT pair's FIFOs are combined to form a single IN or OUT FIFO. In this case only one direction of the endpoint IN/OUT pair may be used at a time. The endpoint direction (IN/OUT) is determined by the DIRSEL bit in the corresponding endpoint's EINCSRH register (see SFR Definition 16.20). Rev. 0.5 171 C8051F340/1/2/3/4/5/6/7 16.5.2. FIFO Double Buffering FIFO slots for Endpoints1-3 can be configured for double-buffered mode. In this mode, the maximum packet size is halved and the FIFO may contain two packets at a time. This mode is available for Endpoints1-3. When an endpoint is configured for Split Mode, double buffering may be enabled for the IN Endpoint and/or the OUT endpoint. When Split Mode is not enabled, double-buffering may be enabled for the entire endpoint FIFO. See Table 16.3 for a list of maximum packet sizes for each FIFO configuration. Table 16.3. FIFO Configurations Endpoint Number 0 1 2 3 Split Mode Enabled? N/A N Y N Y N Y Maximum IN Packet Size (Double Buffer Disabled / Enabled) Maximum OUT Packet Size (Double Buffer Disabled / Enabled) 64 128 / 64 64 / 32 256 / 128 128 / 64 512 / 256 256 / 128 256 / 128 128 / 64 64 / 32 16.5.1. FIFO Access Each endpoint FIFO is accessed through a corresponding FIFOn register. A read of an endpoint FIFOn register unloads one byte from the FIFO; a write of an endpoint FIFOn register loads one byte into the endpoint FIFO. When an endpoint FIFO is configured for Split Mode, a read of the endpoint FIFOn register unloads one byte from the OUT endpoint FIFO; a write of the endpoint FIFOn register loads one byte into the IN endpoint FIFO. USB Register Definition 16.6. FIFOn: USB0 Endpoint FIFO Access R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value FIFODATA 00000000 USB Address: 0x20 - 0x23 USB Addresses 0x20-0x23 provide access to the 4 pairs of endpoint FIFOs: IN/OUT Endpoint FIFO 0 1 2 3 USB Address 0x20 0x21 0x22 0x23 Writing to the FIFO address loads data into the IN FIFO for the corresponding endpoint. Reading from the FIFO address unloads data from the OUT FIFO for the corresponding endpoint. 172 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 16.6. Function Addressing The FADDR register holds the current USB0 function address. Software should write the host-assigned 7-bit function address to the FADDR register when received as part of a SET_ADDRESS command. A new address written to FADDR will not take effect (USB0 will not respond to the new address) until the end of the current transfer (typically following the status phase of the SET_ADDRESS command transfer). The UPDATE bit (FADDR.7) is set to `1' by hardware when software writes a new address to the FADDR register. Hardware clears the UPDATE bit when the new address takes effect as described above. USB Register Definition 16.7. FADDR: USB0 Function Address R R/W Bit6 R/W Bit5 R/W Bit4 R/W R/W Bit2 R/W Bit1 R/W Bit0 Reset Value Update Bit7 Function Address Bit3 00000000 USB Address: 0x00 Bit7: Update: Function Address Update Set to `1' when software writes the FADDR register. USB0 clears this bit to `0' when the new address takes effect. 0: The last address written to FADDR is in effect. 1: The last address written to FADDR is not yet in effect. Bits6-0: Function Address Holds the 7-bit function address for USB0. This address should be written by software when the SET_ADDRESS standard device request is received on Endpoint0. The new address takes effect when the device request completes. 16.7. Function Configuration and Control The USB register POWER (SFR Definition 16.8) is used to configure and control USB0 at the device level (enable/disable, Reset/Suspend/Resume handling, etc.). USB Reset: The USBRST bit (POWER.3) is set to `1' by hardware when Reset signaling is detected on the bus. Upon this detection, the following occur: 1. The USB0 Address is reset (FADDR = 0x00). 2. Endpoint FIFOs are flushed. 3. Control/status registers are reset to 0x00 (E0CSR, EINCSRL, EINCSRH, EOUTCSRL, EOUTCSRH). 4. USB register INDEX is reset to 0x00. 5. All USB interrupts (excluding the Suspend interrupt) are enabled and their corresponding flags cleared. 6. A USB Reset interrupt is generated if enabled. Writing a `1' to the USBRST bit will generate an asynchronous USB0 reset. All USB registers are reset to their default values following this asynchronous reset. Suspend Mode: With Suspend Detection enabled (SUSEN = `1'), USB0 will enter Suspend Mode when Suspend signaling is detected on the bus. An interrupt will be generated if enabled (SUSINTE = `1'). The Suspend Interrupt Service Routine (ISR) should perform application-specific configuration tasks such as disabling appropriate peripherals and/or configuring clock sources for low power modes. See Section Rev. 0.5 173 C8051F340/1/2/3/4/5/6/7 "14. Oscillators" on page 135 for more details on internal oscillator configuration, including the Suspend mode feature of the internal oscillator. USB0 exits Suspend mode when any of the following occur: (1) Resume signaling is detected or generated, (2) Reset signaling is detected, or (3) a device or USB reset occurs. If suspended, the internal oscillator will exit Suspend mode upon any of the above listed events. Resume Signaling: USB0 will exit Suspend mode if Resume signaling is detected on the bus. A Resume interrupt will be generated upon detection if enabled (RESINTE = `1'). Software may force a Remote Wakeup by writing `1' to the RESUME bit (POWER.2). When forcing a Remote Wakeup, software should write RESUME = `0' to end Resume signaling 10-15 ms after the Remote Wakeup is initiated (RESUME = `1'). ISO Update: When software writes `1' to the ISOUP bit (POWER.7), the ISO Update function is enabled. With ISO Update enabled, new packets written to an ISO IN endpoint will not be transmitted until a new Start-Of-Frame (SOF) is received. If the ISO IN endpoint receives an IN token before a SOF, USB0 will transmit a zero-length packet. When ISOUP = `1', ISO Update is enabled for all ISO endpoints. USB Enable: USB0 is disabled following a Power-On-Reset (POR). USB0 is enabled by clearing the USBINH bit (POWER.4). Once written to `0', the USBINH can only be set to `1' by one of the following: (1) a Power-On-Reset (POR), or (2) an asynchronous USB0 reset generated by writing `1' to the USBRST bit (POWER.3). Software should perform all USB0 configuration before enabling USB0. The configuration sequence should be performed as follows: Step 1. Step 2. Step 3. Step 4. Step 5. Select and enable the USB clock source. Reset USB0 by writing USBRST= `1'. Configure and enable the USB Transceiver. Perform any USB0 function configuration (interrupts, Suspend detect). Enable USB0 by writing USBINH = `0'. 174 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.8. POWER: USB0 Power R/W R/W R/W R/W R/W Bit3 R/W Bit2 R R/W Reset Value ISOUD Bit7 Bit6 Bit5 USBINH Bit4 USBRST RESUME SUSMD Bit1 SUSEN Bit0 00010000 USB Address: 0x01 ISOUD: ISO Update This bit affects all IN Isochronous endpoints. 0: When software writes INPRDY = `1', USB0 will send the packet when the next IN token is received. 1: When software writes INPRDY = `1', USB0 will wait for a SOF token before sending the packet. If an IN token is received before a SOF token, USB0 will send a zero-length data packet. Bits6-5: Unused. Read = 00b. Write = don't care. Bit4: USBINH: USB0 Inhibit This bit is set to `1' following a power-on reset (POR) or an asynchronous USB0 reset (see Bit3: RESET). Software should clear this bit after all USB0 and transceiver initialization is complete. Software cannot set this bit to `1'. 0: USB0 enabled. 1: USB0 inhibited. All USB traffic is ignored. Bit3: USBRST: Reset Detect Writing `1' to this bit forces an asynchronous USB0 reset. Reading this bit provides bus reset status information. Read: 0: Reset signaling is not present on the bus. 1: Reset signaling detected on the bus. Bit2: RESUME: Force Resume Software can force resume signaling on the bus to wake USB0 from suspend mode. Writing a `1' to this bit while in Suspend mode (SUSMD = `1') forces USB0 to generate Resume signaling on the bus (a remote Wakeup event). Software should write RESUME = `0' after 10 ms to15 ms to end the Resume signaling. An interrupt is generated, and hardware clears SUSMD, when software writes RESUME = `0'. Bit1: SUSMD: Suspend Mode Set to `1' by hardware when USB0 enters suspend mode. Cleared by hardware when software writes RESUME = `0' (following a remote wakeup) or reads the CMINT register after detection of Resume signaling on the bus. 0: USB0 not in suspend mode. 1: USB0 in suspend mode. Bit0: SUSEN: Suspend Detection Enable 0: Suspend detection disabled. USB0 will ignore suspend signaling on the bus. 1: Suspend detection enabled. USB0 will enter suspend mode if it detects suspend signaling on the bus. Bit7: Rev. 0.5 175 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.9. FRAMEL: USB0 Frame Number Low R Bit7 R Bit6 R Bit5 R Bit4 R Bit3 R Bit2 R Bit1 R Bit0 Reset Value Frame Number Low 00000000 USB Address: 0x0C Bits7-0: Frame Number Low This register contains bits7-0 of the last received frame number. USB Register Definition 16.10. FRAMEH: USB0 Frame Number High R R R R R R Bit2 R R Bit0 Reset Value Bit7 Bit6 Bit5 Bit4 Bit3 Frame Number High Bit1 00000000 USB Address: 0x0D Bits7-3: Bits2-0: Unused. Read = 0. Write = don't care. Frame Number High Byte This register contains bits10-8 of the last received frame number. 16.8. Interrupts The read-only USB0 interrupt flags are located in the USB registers shown in USB Register Definition 16.11 through USB Register Definition 16.13. The associated interrupt enable bits are located in the USB registers shown in USB Register Definition 16.14 through USB Register Definition 16.16. A USB0 interrupt is generated when any of the USB interrupt flags is set to `1'. The USB0 interrupt is enabled via the EIE1 SFR (see Section "9.3. Interrupt Handler" on page 87). Important Note: Reading a USB interrupt flag register resets all flags in that register to `0'. 176 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.11. IN1INT: USB0 IN Endpoint Interrupt R R R R R R R R Reset Value Bit7 Bit6 Bit5 Bit4 IN3 Bit3 IN2 Bit2 IN1 Bit1 EP0 Bit0 00000000 USB Address: 0x02 Bits7-4: Unused. Read = 0000b. Write = don't care. Bit3: IN3: IN Endpoint 3 Interrupt-pending Flag This bit is cleared when software reads the IN1INT register. 0: IN Endpoint 3 interrupt inactive. 1: IN Endpoint 3 interrupt active. Bit2: IN2: IN Endpoint 2 Interrupt-pending Flag This bit is cleared when software reads the IN1INT register. 0: IN Endpoint 2 interrupt inactive. 1: IN Endpoint 2 interrupt active. Bit1: IN1: IN Endpoint 1 Interrupt-pending Flag This bit is cleared when software reads the IN1INT register. 0: IN Endpoint 1 interrupt inactive. 1: IN Endpoint 1 interrupt active. Bit0: EP0: Endpoint 0 Interrupt-pending Flag This bit is cleared when software reads the IN1INT register. 0: Endpoint 0 interrupt inactive. 1: Endpoint 0 interrupt active. USB Register Definition 16.12. OUT1INT: USB0 Out Endpoint Interrupt R R R R R R R R Reset Value Bit7 Bit6 Bit5 Bit4 OUT3 Bit3 OUT2 Bit2 OUT1 Bit1 Bit0 00000000 USB Address: 0x04 Bits7-4: Unused. Read = 0000b. Write = don't care. Bit3: OUT3: OUT Endpoint 3 Interrupt-pending Flag This bit is cleared when software reads the OUT1INT register. 0: OUT Endpoint 3 interrupt inactive. 1: OUT Endpoint 3 interrupt active. Bit2: OUT2: OUT Endpoint 2 Interrupt-pending Flag This bit is cleared when software reads the OUT1INT register. 0: OUT Endpoint 2 interrupt inactive. 1: OUT Endpoint 2 interrupt active. Bit1: OUT1: OUT Endpoint 1 Interrupt-pending Flag This bit is cleared when software reads the OUT1INT register. 0: OUT Endpoint 1 interrupt inactive. 1: OUT Endpoint 1 interrupt active. Bit0: Unused. Read = 0; Write = don't care. Rev. 0.5 177 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.13. CMINT: USB0 Common Interrupt R R R R R R R R Reset Value Bit7 Bit6 Bit5 Bit4 SOF Bit3 RSTINT Bit2 RSUINT Bit1 SUSINT Bit0 00000000 USB Address: 0x06 Bits7-4: Unused. Read = 0000b; Write = don't care. Bit3: SOF: Start of Frame Interrupt Set by hardware when a SOF token is received. This interrupt event is synthesized by hardware: an interrupt will be generated when hardware expects to receive a SOF event, even if the actual SOF signal is missed or corrupted. This bit is cleared when software reads the CMINT register. 0: SOF interrupt inactive. 1: SOF interrupt active. Bit2: RSTINT: Reset Interrupt-pending Flag Set by hardware when Reset signaling is detected on the bus. This bit is cleared when software reads the CMINT register. 0: Reset interrupt inactive. 1: Reset interrupt active. Bit1: RSUINT: Resume Interrupt-pending Flag Set by hardware when Resume signaling is detected on the bus while USB0 is in suspend mode. This bit is cleared when software reads the CMINT register. 0: Resume interrupt inactive. 1: Resume interrupt active. Bit0: SUSINT: Suspend Interrupt-pending Flag When Suspend detection is enabled (bit SUSEN in register POWER), this bit is set by hardware when Suspend signaling is detected on the bus. This bit is cleared when software reads the CMINT register. 0: Suspend interrupt inactive. 1: Suspend interrupt active. 178 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.14. IN1IE: USB0 IN Endpoint Interrupt Enable R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 Bit6 Bit5 Bit4 IN3E Bit3 IN2E Bit2 IN1E Bit1 EP0E Bit0 00001111 USB Address: 0x07 Bits7-4: Unused. Read = 0000b. Write = don't care. Bit3: IN3E: IN Endpoint 3 Interrupt Enable 0: IN Endpoint 3 interrupt disabled. 1: IN Endpoint 3 interrupt enabled. Bit2: IN2E: IN Endpoint 2 Interrupt Enable 0: IN Endpoint 2 interrupt disabled. 1: IN Endpoint 2 interrupt enabled. Bit1: IN1E: IN Endpoint 1 Interrupt Enable 0: IN Endpoint 1 interrupt disabled. 1: IN Endpoint 1 interrupt enabled. Bit0: EP0E: Endpoint 0 Interrupt Enable 0: Endpoint 0 interrupt disabled. 1: Endpoint 0 interrupt enabled. USB Register Definition 16.15. OUT1IE: USB0 Out Endpoint Interrupt Enable R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Bit7 Bit6 Bit5 Bit4 OUT3E Bit3 OUT2E Bit2 OUT1E Bit1 Bit0 00001110 USB Address: 0x09 Bits7-4: Unused. Read = 0000b. Write = don't care. Bit3: OUT3E: OUT Endpoint 3 Interrupt Enable 0: OUT Endpoint 3 interrupt disabled. 1: OUT Endpoint 3 interrupt enabled. Bit2: OUT2E: OUT Endpoint 2 Interrupt Enable 0: OUT Endpoint 2 interrupt disabled. 1: OUT Endpoint 2 interrupt enabled. Bit1: OUT1E: OUT Endpoint 1 Interrupt Enable 0: OUT Endpoint 1 interrupt disabled. 1: OUT Endpoint 1 interrupt enabled. Bit0: Unused. Read = 0; Write = don't' care. Rev. 0.5 179 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.16. CMIE: USB0 Common Interrupt Enable R/W R/W R/W R/W R/W R/W Bit2 R/W Bit1 R/W Bit0 Reset Value USB Address: Bit7 Bit6 Bit5 Bit4 SOFE Bit3 RSTINTE RSUINTE SUSINTE 00000110 0x0B Bits7-4: Unused. Read = 0000b; Write = don't care. Bit3: SOFE: Start of Frame Interrupt Enable 0: SOF interrupt disabled. 1: SOF interrupt enabled. Bit2: RSTINTE: Reset Interrupt Enable 0: Reset interrupt disabled. 1: Reset interrupt enabled. Bit1: RSUINTE: Resume Interrupt Enable 0: Resume interrupt disabled. 1: Resume interrupt enabled. Bit0: SUSINTE: Suspend Interrupt Enable 0: Suspend interrupt disabled. 1: Suspend interrupt enabled. 16.9. The Serial Interface Engine The Serial Interface Engine (SIE) performs all low level USB protocol tasks, interrupting the processor when data has successfully been transmitted or received. When receiving data, the SIE will interrupt the processor when a complete data packet has been received; appropriate handshaking signals are automatically generated by the SIE. When transmitting data, the SIE will interrupt the processor when a complete data packet has been transmitted and the appropriate handshake signal has been received. The SIE will not interrupt the processor when corrupted/erroneous packets are received. 16.10. Endpoint0 Endpoint0 is managed through the USB register E0CSR (USB Register Definition 16.17). The INDEX register must be loaded with 0x00 to access the E0CSR register. An Endpoint0 interrupt is generated when: 1. A data packet (OUT or SETUP) has been received and loaded into the Endpoint0 FIFO. The OPRDY bit (E0CSR.0) is set to `1' by hardware. 2. An IN data packet has successfully been unloaded from the Endpoint0 FIFO and transmitted to the host; INPRDY is reset to `0' by hardware. 3. An IN transaction is completed (this interrupt generated during the status stage of the transaction). 4. Hardware sets the STSTL bit (E0CSR.2) after a control transaction ended due to a protocol violation. 5. Hardware sets the SUEND bit (E0CSR.4) because a control transfer ended before firmware sets the DATAEND bit (E0CSR.3). 180 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 The E0CNT register (USB Register Definition 16.18) holds the number of received data bytes in the Endpoint0 FIFO. Hardware will automatically detect protocol errors and send a STALL condition in response. Firmware may force a STALL condition to abort the current transfer. When a STALL condition is generated, the STSTL bit will be set to `1' and an interrupt generated. The following conditions will cause hardware to generate a STALL condition: 1. The host sends an OUT token during a OUT data phase after the DATAEND bit has been set to `1'. 2. The host sends an IN token during an IN data phase after the DATAEND bit has been set to `1'. 3. The host sends a packet that exceeds the maximum packet size for Endpoint0. 4. The host sends a non-zero length DATA1 packet during the status phase of an IN transaction. Firmware sets the SDSTL bit (E0CSR.5) to `1'. 16.10.1.Endpoint0 SETUP Transactions All control transfers must begin with a SETUP packet. SETUP packets are similar to OUT packets, containing an 8-byte data field sent by the host. Any SETUP packet containing a command field of anything other than 8 bytes will be automatically rejected by USB0. An Endpoint0 interrupt is generated when the data from a SETUP packet is loaded into the Endpoint0 FIFO. Software should unload the command from the Endpoint0 FIFO, decode the command, perform any necessary tasks, and set the SOPRDY bit to indicate that it has serviced the OUT packet. 16.10.2.Endpoint0 IN Transactions When a SETUP request is received that requires USB0 to transmit data to the host, one or more IN requests will be sent by the host. For the first IN transaction, firmware should load an IN packet into the Endpoint0 FIFO, and set the INPRDY bit (E0CSR.1). An interrupt will be generated when an IN packet is transmitted successfully. Note that no interrupt will be generated if an IN request is received before firmware has loaded a packet into the Endpoint0 FIFO. If the requested data exceeds the maximum packet size for Endpoint0 (as reported to the host), the data should be split into multiple packets; each packet should be of the maximum packet size excluding the last (residual) packet. If the requested data is an integer multiple of the maximum packet size for Endpoint0, the last data packet should be a zero-length packet signaling the end of the transfer. Firmware should set the DATAEND bit to `1' after loading into the Endpoint0 FIFO the last data packet for a transfer. Upon reception of the first IN token for a particular control transfer, Endpoint0 is said to be in Transmit Mode. In this mode, only IN tokens should be sent by the host to Endpoint0. The SUEND bit (E0CSR.4) is set to `1' if a SETUP or OUT token is received while Endpoint0 is in Transmit Mode. Endpoint0 will remain in Transmit Mode until any of the following occur: 1. USB0 receives an Endpoint0 SETUP or OUT token. 2. Firmware sends a packet less than the maximum Endpoint0 packet size. 3. Firmware sends a zero-length packet. Firmware should set the DATAEND bit (E0CSR.3) to `1' when performing (2) and (3) above. The SIE will transmit a NAK in response to an IN token if there is no packet ready in the IN FIFO (INPRDY = `0'). Rev. 0.5 181 C8051F340/1/2/3/4/5/6/7 16.10.3.Endpoint0 OUT Transactions When a SETUP request is received that requires the host to transmit data to USB0, one or more OUT requests will be sent by the host. When an OUT packet is successfully received by USB0, hardware will set the OPRDY bit (E0CSR.0) to `1' and generate an Endpoint0 interrupt. Following this interrupt, firmware should unload the OUT packet from the Endpoint0 FIFO and set the SOPRDY bit (E0CSR.6) to `1'. If the amount of data required for the transfer exceeds the maximum packet size for Endpoint0, the data will be split into multiple packets. If the requested data is an integer multiple of the maximum packet size for Endpoint0 (as reported to the host), the host will send a zero-length data packet signaling the end of the transfer. Upon reception of the first OUT token for a particular control transfer, Endpoint0 is said to be in Receive Mode. In this mode, only OUT tokens should be sent by the host to Endpoint0. The SUEND bit (E0CSR.4) is set to `1' if a SETUP or IN token is received while Endpoint0 is in Receive Mode. Endpoint0 will remain in Receive mode until: 1. The SIE receives a SETUP or IN token. 2. The host sends a packet less than the maximum Endpoint0 packet size. 3. The host sends a zero-length packet. Firmware should set the DATAEND bit (E0CSR.3) to `1' when the expected amount of data has been received. The SIE will transmit a STALL condition if the host sends an OUT packet after the DATAEND bit has been set by firmware. An interrupt will be generated with the STSTL bit (E0CSR.2) set to `1' after the STALL is transmitted. 182 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.17. E0CSR: USB0 Endpoint0 Control R/W Bit7 R/W Bit6 R/W R Bit4 R/W Bit3 R/W R/W R Reset Value SSUEND SOPRDY SDSTL Bit5 SUEND DATAEND STSTL Bit2 INPRDY Bit1 OPRDY Bit0 00000000 USB Address: 0x11 Bit7: SSUEND: Serviced Setup End Write: Software should set this bit to `1' after servicing a Setup End (bit SUEND) event. Hardware clears the SUEND bit when software writes `1' to SSUEND. Read: This bit always reads `0'. SOPRDY: Serviced OPRDY Write: Software should write `1' to this bit after servicing a received Endpoint0 packet. The OPRDY bit will be cleared by a write of `1' to SOPRDY. Read: This bit always reads `0'. SDSTL: Send Stall Software can write `1' to this bit to terminate the current transfer (due to an error condition, unexpected transfer request, etc.). Hardware will clear this bit to `0' when the STALL handshake is transmitted. SUEND: Setup End Hardware sets this read-only bit to `1' when a control transaction ends before software has written `1' to the DATAEND bit. Hardware clears this bit when software writes `1' to SSUEND. DATAEND: Data End Software should write `1' to this bit: 1. When writing `1' to INPRDY for the last outgoing data packet. 2. When writing `1' to INPRDY for a zero-length data packet. 3. When writing `1' to SOPRDY after servicing the last incoming data packet. This bit is automatically cleared by hardware. STSTL: Sent Stall Hardware sets this bit to `1' after transmitting a STALL handshake signal. This flag must be cleared by software. INPRDY: IN Packet Ready Software should write `1' to this bit after loading a data packet into the Endpoint0 FIFO for transmit. Hardware clears this bit and generates an interrupt under either of the following conditions: 1. The packet is transmitted. 2. The packet is overwritten by an incoming SETUP packet. 3. The packet is overwritten by an incoming OUT packet. OPRDY: OUT Packet Ready Hardware sets this read-only bit and generates an interrupt when a data packet has been received. This bit is cleared only when software writes `1' to the SOPRDY bit. Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: Rev. 0.5 183 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.18. E0CNT: USB0 Endpoint 0 Data Count R R Bit6 R Bit5 R Bit4 R R Bit2 R Bit1 R Bit0 Reset Value Bit7 E0CNT Bit3 00000000 USB Address: 0x16 Bit7: Unused. Read = 0; Write = don't care. Bits6-0: E0CNT: Endpoint 0 Data Count This 7-bit number indicates the number of received data bytes in the Endpoint 0 FIFO. This number is only valid while bit OPRDY is a `1'. 16.11. Configuring Endpoints1-3 Endpoints1-3 are configured and controlled through their own sets of the following control/status registers: IN registers EINCSRL and EINCSRH, and OUT registers EOUTCSRL and EOUTCSRH. Only one set of endpoint control/status registers is mapped into the USB register address space at a time, defined by the contents of the INDEX register (USB Register Definition 16.4). Endpoints1-3 can be configured as IN, OUT, or both IN/OUT (Split Mode) as described in Section 16.5.1. The endpoint mode (Split/Normal) is selected via the SPLIT bit in register EINCSRH. When SPLIT = `1', the corresponding endpoint FIFO is split, and both IN and OUT pipes are available. When SPLIT = `0', the corresponding endpoint functions as either IN or OUT; the endpoint direction is selected by the DIRSEL bit in register EINCSRH. 16.12. Controlling Endpoints1-3 IN Endpoints1-3 IN are managed via USB registers EINCSRL and EINCSRH. All IN endpoints can be used for Interrupt, Bulk, or Isochronous transfers. Isochronous (ISO) mode is enabled by writing `1' to the ISO bit in register EINCSRH. Bulk and Interrupt transfers are handled identically by hardware. An Endpoint1-3 IN interrupt is generated by any of the following conditions: 1. An IN packet is successfully transferred to the host. 2. Software writes `1' to the FLUSH bit (EINCSRL.3) when the target FIFO is not empty. 3. Hardware generates a STALL condition. 16.12.1.Endpoints1-3 IN Interrupt or Bulk Mode When the ISO bit (EINCSRH.6) = `0' the target endpoint operates in Bulk or Interrupt Mode. Once an endpoint has been configured to operate in Bulk/Interrupt IN mode (typically following an Endpoint0 SET_INTERFACE command), firmware should load an IN packet into the endpoint IN FIFO and set the INPRDY bit (EINCSRL.0). Upon reception of an IN token, hardware will transmit the data, clear the INPRDY bit, and generate an interrupt. 184 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Writing `1' to INPRDY without writing any data to the endpoint FIFO will cause a zero-length packet to be transmitted upon reception of the next IN token. A Bulk or Interrupt pipe can be shut down (or Halted) by writing `1' to the SDSTL bit (EINCSRL.4). While SDSTL = `1', hardware will respond to all IN requests with a STALL condition. Each time hardware generates a STALL condition, an interrupt will be generated and the STSTL bit (EINCSRL.5) set to `1'. The STSTL bit must be reset to `0' by firmware. Hardware will automatically reset INPRDY to `0' when a packet slot is open in the endpoint FIFO. Note that if double buffering is enabled for the target endpoint, it is possible for firmware to load two packets into the IN FIFO at a time. In this case, hardware will reset INPRDY to `0' immediately after firmware loads the first packet into the FIFO and sets INPRDY to `1'. An interrupt will not be generated in this case; an interrupt will only be generated when a data packet is transmitted. When firmware writes `1' to the FCDT bit (EINCSRH.3), the data toggle for each IN packet will be toggled continuously, regardless of the handshake received from the host. This feature is typically used by Interrupt endpoints functioning as rate feedback communication for Isochronous endpoints. When FCDT = `0', the data toggle bit will only be toggled when an ACK is sent from the host in response to an IN packet. 16.12.2.Endpoints1-3 IN Isochronous Mode When the ISO bit (EINCSRH.6) is set to `1', the target endpoint operates in Isochronous (ISO) mode. Once an endpoint has been configured for ISO IN mode, the host will send one IN token (data request) per frame; the location of data within each frame may vary. Because of this, it is recommended that double buffering be enabled for ISO IN endpoints. Hardware will automatically reset INPRDY (EINCSRL.0) to `0' when a packet slot is open in the endpoint FIFO. Note that if double buffering is enabled for the target endpoint, it is possible for firmware to load two packets into the IN FIFO at a time. In this case, hardware will reset INPRDY to `0' immediately after firmware loads the first packet into the FIFO and sets INPRDY to `1'. An interrupt will not be generated in this case; an interrupt will only be generated when a data packet is transmitted. If there is not a data packet ready in the endpoint FIFO when USB0 receives an IN token from the host, USB0 will transmit a zero-length data packet and set the UNDRUN bit (EINCSRL.2) to `1'. The ISO Update feature (see Section 16.7) can be useful in starting a double buffered ISO IN endpoint. If the host has already set up the ISO IN pipe (has begun transmitting IN tokens) when firmware writes the first data packet to the endpoint FIFO, the next IN token may arrive and the first data packet sent before firmware has written the second (double buffered) data packet to the FIFO. The ISO Update feature ensures that any data packet written to the endpoint FIFO will not be transmitted during the current frame; the packet will only be sent after a SOF signal has been received. Rev. 0.5 185 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.19. EINCSRL: USB0 IN Endpoint Control Low Byte R W R/W R/W R/W R/W Bit2 R/W Bit1 R/W Reset Value Bit7 CLRDT Bit6 STSTL Bit5 SDSTL Bit4 FLUSH Bit3 UNDRUN FIFONE INPRDY Bit0 00000000 USB Address: 0x11 Bit7: Bit6: Unused. Read = 0; Write = don't care. CLRDT: Clear Data Toggle. Write: Software should write `1' to this bit to reset the IN Endpoint data toggle to `0'. Read: This bit always reads `0'. STSTL: Sent Stall Hardware sets this bit to `1' when a STALL handshake signal is transmitted. The FIFO is flushed, and the INPRDY bit cleared. This flag must be cleared by software. SDSTL: Send Stall. Software should write `1' to this bit to generate a STALL handshake in response to an IN token. Software should write `0' to this bit to terminate the STALL signal. This bit has no effect in ISO mode. FLUSH: FIFO Flush. Writing a `1' to this bit flushes the next packet to be transmitted from the IN Endpoint FIFO. The FIFO pointer is reset and the INPRDY bit is cleared. If the FIFO contains multiple packets, software must write `1' to FLUSH for each packet. Hardware resets the FLUSH bit to `0' when the FIFO flush is complete. UNDRUN: Data Underrun. The function of this bit depends on the IN Endpoint mode: ISO: Set when a zero-length packet is sent after an IN token is received while bit INPRDY = `0'. Interrupt/Bulk: Set when a NAK is returned in response to an IN token. This bit must be cleared by software. FIFONE: FIFO Not Empty. 0: The IN Endpoint FIFO is empty. 1. The IN Endpoint FIFO contains one or more packets. INPRDY: In Packet Ready. Software should write `1' to this bit after loading a data packet into the IN Endpoint FIFO. Hardware clears INPRDY due to any of the following: 1. A data packet is transmitted. 2. Double buffering is enabled (DBIEN = `1') and there is an open FIFO packet slot. 3. If the endpoint is in Isochronous Mode (ISO = `1') and ISOUD = `1', INPRDY will read `0' until the next SOF is received. An interrupt (if enabled) will be generated when hardware clears INPRDY as a result of a packet being transmitted. Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: 186 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.20. EINCSRH: USB0 IN Endpoint Control High Byte R/W R/W R/W R R/W R/W R R Reset Value DBIEN Bit7 ISO Bit6 DIRSEL Bit5 Bit4 FCDT Bit3 SPLIT Bit2 Bit1 Bit0 00000000 USB Address: 0x12 Bit7: DBIEN: IN Endpoint Double-buffer Enable. 0: Double-buffering disabled for the selected IN endpoint. 1: Double-buffering enabled for the selected IN endpoint. Bit6: ISO: Isochronous Transfer Enable. This bit enables/disables isochronous transfers on the current endpoint. 0: Endpoint configured for bulk/interrupt transfers. 1: Endpoint configured for isochronous transfers. Bit5: DIRSEL: Endpoint Direction Select. This bit is valid only when the selected FIFO is not split (SPLIT = `0'). 0: Endpoint direction selected as OUT. 1: Endpoint direction selected as IN. Bit4: Unused. Read = `0'. Write = don't care. Bit3: FCDT: Force Data Toggle. 0: Endpoint data toggle switches only when an ACK is received following a data packet transmission. 1: Endpoint data toggle forced to switch after every data packet is transmitted, regardless of ACK reception. Bit2: SPLIT: FIFO Split Enable. When SPLIT = `1', the selected endpoint FIFO is split. The upper half of the selected FIFO is used by the IN endpoint; the lower half of the selected FIFO is used by the OUT endpoint. Bits1-0: Unused. Read = 00b; Write = don't care. 16.13. Controlling Endpoints1-3 OUT Endpoints1-3 OUT are managed via USB registers EOUTCSRL and EOUTCSRH. All OUT endpoints can be used for Interrupt, Bulk, or Isochronous transfers. Isochronous (ISO) mode is enabled by writing `1' to the ISO bit in register EOUTCSRH. Bulk and Interrupt transfers are handled identically by hardware. An Endpoint1-3 OUT interrupt may be generated by the following: 1. Hardware sets the OPRDY bit (EINCSRL.0) to `1'. 2. Hardware generates a STALL condition. 16.13.1.Endpoints1-3 OUT Interrupt or Bulk Mode When the ISO bit (EOUTCSRH.6) = `0' the target endpoint operates in Bulk or Interrupt mode. Once an endpoint has been configured to operate in Bulk/Interrupt OUT mode (typically following an Endpoint0 SET_INTERFACE command), hardware will set the OPRDY bit (EOUTCSRL.0) to `1' and generate an interrupt upon reception of an OUT token and data packet. The number of bytes in the current OUT data packet (the packet ready to be unloaded from the FIFO) is given in the EOUTCNTH and EOUTCNTL registers. In response to this interrupt, firmware should unload the data packet from the OUT FIFO and reset the OPRDY bit to `0'. Rev. 0.5 187 C8051F340/1/2/3/4/5/6/7 A Bulk or Interrupt pipe can be shut down (or Halted) by writing `1' to the SDSTL bit (EOUTCSRL.5). While SDSTL = `1', hardware will respond to all OUT requests with a STALL condition. Each time hardware generates a STALL condition, an interrupt will be generated and the STSTL bit (EOUTCSRL.6) set to `1'. The STSTL bit must be reset to `0' by firmware. Hardware will automatically set OPRDY when a packet is ready in the OUT FIFO. Note that if double buffering is enabled for the target endpoint, it is possible for two packets to be ready in the OUT FIFO at a time. In this case, hardware will set OPRDY to `1' immediately after firmware unloads the first packet and resets OPRDY to `0'. A second interrupt will be generated in this case. 16.13.2.Endpoints1-3 OUT Isochronous Mode When the ISO bit (EOUTCSRH.6) is set to `1', the target endpoint operates in Isochronous (ISO) mode. Once an endpoint has been configured for ISO OUT mode, the host will send exactly one data per USB frame; the location of the data packet within each frame may vary, however. Because of this, it is recommended that double buffering be enabled for ISO OUT endpoints. Each time a data packet is received, hardware will load the received data packet into the endpoint FIFO, set the OPRDY bit (EOUTCSRL.0) to `1', and generate an interrupt (if enabled). Firmware would typically use this interrupt to unload the data packet from the endpoint FIFO and reset the OPRDY bit to `0'. If a data packet is received when there is no room in the endpoint FIFO, an interrupt will be generated and the OVRUN bit (EOUTCSRL.2) set to `1'. If USB0 receives an ISO data packet with a CRC error, the data packet will be loaded into the endpoint FIFO, OPRDY will be set to `1', an interrupt (if enabled) will be generated, and the DATAERR bit (EOUTCSRL.3) will be set to `1'. Software should check the DATAERR bit each time a data packet is unloaded from an ISO OUT endpoint FIFO. 188 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.21. EOUTCSRL: USB0 OUT Endpoint Control Low Byte W R/W R/W R/W R R/W R R/W Reset Value CLRDT Bit7 STSTL Bit6 SDSTL Bit5 FLUSH Bit4 DATERR Bit3 OVRUN Bit2 FIFOFUL Bit1 OPRDY Bit0 00000000 USB Address: 0x14 Bit7: CLRDT: Clear Data Toggle Write: Software should write `1' to this bit to reset the OUT endpoint data toggle to `0'. Read: This bit always reads `0'. STSTL: Sent Stall Hardware sets this bit to `1' when a STALL handshake signal is transmitted. This flag must be cleared by software. SDSTL: Send Stall Software should write `1' to this bit to generate a STALL handshake. Software should write `0' to this bit to terminate the STALL signal. This bit has no effect in ISO mode. FLUSH: FIFO Flush Writing a `1' to this bit flushes the next packet to be read from the OUT endpoint FIFO. The FIFO pointer is reset and the OPRDY bit is cleared. If the FIFO contains multiple packets, software must write `1' to FLUSH for each packet. Hardware resets the FLUSH bit to `0' when the FIFO flush is complete. Note: If data for the current packet has already been read from the FIFO, the FLUSH bit should not be used to flush the packet. Instead, the entire data packet should be read from the FIFO manually. Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: DATERR: Data Error In ISO mode, this bit is set by hardware if a received packet has a CRC or bit-stuffing error. It is cleared when software clears OPRDY. This bit is only valid in ISO mode. OVRUN: Data Overrun This bit is set by hardware when an incoming data packet cannot be loaded into the OUT endpoint FIFO. This bit is only valid in ISO mode, and must be cleared by software. 0: No data overrun. 1: A data packet was lost because of a full FIFO since this flag was last cleared. FIFOFUL: OUT FIFO Full This bit indicates the contents of the OUT FIFO. If double buffering is enabled for the endpoint (DBIEN = `1'), the FIFO is full when the FIFO contains two packets. If DBIEN = `0', the FIFO is full when the FIFO contains one packet. 0: OUT endpoint FIFO is not full. 1: OUT endpoint FIFO is full. OPRDY: OUT Packet Ready Hardware sets this bit to `1' and generates an interrupt when a data packet is available. Software should clear this bit after each data packet is unloaded from the OUT endpoint FIFO. Rev. 0.5 189 C8051F340/1/2/3/4/5/6/7 USB Register Definition 16.22. EOUTCSRH: USB0 OUT Endpoint Control High Byte R/W R/W R/W R/W R R R R Reset Value DBOEN Bit7 ISO Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 00000000 USB Address: 0x15 DBOEN: Double-buffer Enable 0: Double-buffering disabled for the selected OUT endpoint. 1: Double-buffering enabled for the selected OUT endpoint. Bit6: ISO: Isochronous Transfer Enable This bit enables/disables isochronous transfers on the current endpoint. 0: Endpoint configured for bulk/interrupt transfers. 1: Endpoint configured for isochronous transfers. Bits5-0: Unused. Read = 000000b; Write = don't care. Bit7: USB Register Definition 16.23. EOUTCNTL: USB0 OUT Endpoint Count Low R Bit7 R Bit6 R Bit5 R R R Bit2 R Bit1 R Bit0 Reset Value EOCL Bit4 Bit3 00000000 USB Address: 0x16 Bits7-0: EOCL: OUT Endpoint Count Low Byte EOCL holds the lower 8-bits of the 10-bit number of data bytes in the last received packet in the current OUT endpoint FIFO. This number is only valid while OPRDY = `1'. USB Register Definition 16.24. EOUTCNTH: USB0 OUT Endpoint Count High R R R R R R R R Reset Value Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 E0CH Bit0 00000000 USB Address: 0x17 Bits7-2: Unused. Read = 00000. Write = don't care. Bits1-0: EOCH: OUT Endpoint Count High Byte EOCH holds the upper 2-bits of the 10-bit number of data bytes in the last received packet in the current OUT endpoint FIFO. This number is only valid while OPRDY = `1'. 190 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 16.4. USB Transceiver Electrical Characteristics VDD = 3.0 to 3.6 V, -40 to +85 C unless otherwise specified Parameters Symbol Conditions Transmitter VOH Output High Voltage VOL Output Low Voltage VCRS Output Crossover Point Driving High ZDRV Output Impedance Driving Low Full Speed (D+ Pull-up) RPU Pull-up Resistance Low Speed (D- Pull-up) Low Speed TR Output Rise Time Full Speed Low Speed TF Output Fall Time Full Speed Receiver Differential Input VDI | (D+) - (D-) | Sensitivity Differential Input Common VCM Mode Range IL Pullups Disabled Input Leakage Current Min 2.8 1.3 38 38 1.425 75 4 75 4 0.2 0.8 <1.0 2.5 1.5 1.575 300 20 300 20 0.8 2.0 Typ Max Units V V V k ns ns V V A Note: Refer to the USB Specification for timing diagrams and symbol definitions. Rev. 0.5 191 C8051F340/1/2/3/4/5/6/7 NOTES: 192 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 17. SMBus The SMBus I/O interface is a two-wire, bi-directional serial bus. The SMBus is compliant with the System Management Bus Specification, version 1.1, and compatible with the I2C serial bus. Reads and writes to the interface by the system controller are byte oriented with the SMBus interface autonomously controlling the serial transfer of the data. Data can be transferred at up to 1/10th of the system clock as a master or slave (this can be faster than allowed by the SMBus specification, depending on the system clock used). A method of extending the clock-low duration is available to accommodate devices with different speed capabilities on the same bus. The SMBus interface may operate as a master and/or slave, and may function on a bus with multiple masters. The SMBus provides control of SDA (serial data), SCL (serial clock) generation and synchronization, arbitration logic, and START/STOP control and generation. Three SFRs are associated with the SMBus: SMB0CF configures the SMBus; SMB0CN controls the status of the SMBus; and SMB0DAT is the data register, used for both transmitting and receiving SMBus data and slave addresses. SMB0CN MTSSAAAS AXTTCRC I SMAOKBK TO RL ED QO RE S T SMB0CF E I BESSSS N N U XMMMM SHSTBBBB M YHTFCC B OOT S S LEE10 D 00 01 10 11 SMBUS CONTROL LOGIC Arbitration SCL Synchronization SCL Generation (Master Mode) SDA Control Data Path IRQ Generation Control T0 Overflow T1 Overflow TMR2H Overflow TMR2L Overflow SCL FILTER Interrupt Request SCL Control SDA Control N C R O S S B A R SDA Port I/O SMB0DAT 76543210 FILTER N Figure 17.1. SMBus Block Diagram Rev. 0.5 193 C8051F340/1/2/3/4/5/6/7 17.1. Supporting Documents It is assumed the reader is familiar with or has access to the following supporting documents: 1. The I2C-Bus and How to Use It (including specifications), Philips Semiconductor. 2. The I2C-Bus Specification -- Version 2.0, Philips Semiconductor. 3. System Management Bus Specification -- Version 1.1, SBS Implementers Forum. 17.2. SMBus Configuration Figure 17.2 shows a typical SMBus configuration. The SMBus specification allows any recessive voltage between 3.0 V and 5.0 V; different devices on the bus may operate at different voltage levels. The bi-directional SCL (serial clock) and SDA (serial data) lines must be connected to a positive power supply voltage through a pull-up resistor or similar circuit. Every device connected to the bus must have an open-drain or open-collector output for both the SCL and SDA lines, so that both are pulled high (recessive state) when the bus is free. The maximum number of devices on the bus is limited only by the requirement that the rise and fall times on the bus not exceed 300 ns and 1000 ns, respectively. VDD = 5V VDD = 3V VDD = 5V VDD = 3V Master Device Slave Device 1 Slave Device 2 SDA SCL Figure 17.2. Typical SMBus Configuration 17.3. SMBus Operation Two types of data transfers are possible: data transfers from a master transmitter to an addressed slave receiver (WRITE), and data transfers from an addressed slave transmitter to a master receiver (READ). The master device initiates both types of data transfers and provides the serial clock pulses on SCL. The SMBus interface may operate as a master or a slave, and multiple master devices on the same bus are supported. If two or more masters attempt to initiate a data transfer simultaneously, an arbitration scheme is employed with a single master always winning the arbitration. Note that it is not necessary to specify one device as the Master in a system; any device who transmits a START and a slave address becomes the master for the duration of that transfer. A typical SMBus transaction consists of a START condition followed by an address byte (Bits7-1: 7-bit slave address; Bit0: R/W direction bit), one or more bytes of data, and a STOP condition. Each byte that is received (by a master or slave) must be acknowledged (ACK) with a low SDA during a high SCL (see Figure 17.3). If the receiving device does not ACK, the transmitting device will read a NACK (not acknowledge), which is a high SDA during a high SCL. 194 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 The direction bit (R/W) occupies the least-significant bit position of the address byte. The direction bit is set to logic 1 to indicate a "READ" operation and cleared to logic 0 to indicate a "WRITE" operation. All transactions are initiated by a master, with one or more addressed slave devices as the target. The master generates the START condition and then transmits the slave address and direction bit. If the transaction is a WRITE operation from the master to the slave, the master transmits the data a byte at a time waiting for an ACK from the slave at the end of each byte. For READ operations, the slave transmits the data waiting for an ACK from the master at the end of each byte. At the end of the data transfer, the master generates a STOP condition to terminate the transaction and free the bus. Figure 17.3 illustrates a typical SMBus transaction. SCL SDA SLA6 SLA5-0 R/W D7 D6-0 START Slave Address + R/W ACK Data Byte NACK STOP Figure 17.3. SMBus Transaction 17.3.1. Arbitration A master may start a transfer only if the bus is free. The bus is free after a STOP condition or after the SCL and SDA lines remain high for a specified time (see Section "17.3.4. SCL High (SMBus Free) Timeout" on page 196). In the event that two or more devices attempt to begin a transfer at the same time, an arbitration scheme is employed to force one master to give up the bus. The master devices continue transmitting until one attempts a HIGH while the other transmits a LOW. Since the bus is open-drain, the bus will be pulled LOW. The master attempting the HIGH will detect a LOW SDA and lose the arbitration. The winning master continues its transmission without interruption; the losing master becomes a slave and receives the rest of the transfer if addressed. This arbitration scheme is non-destructive: one device always wins, and no data is lost. Rev. 0.5 195 C8051F340/1/2/3/4/5/6/7 17.3.2. Clock Low Extension SMBus provides a clock synchronization mechanism, similar to I2C, which allows devices with different speed capabilities to coexist on the bus. A clock-low extension is used during a transfer in order to allow slower slave devices to communicate with faster masters. The slave may temporarily hold the SCL line LOW to extend the clock low period, effectively decreasing the serial clock frequency. 17.3.3. SCL Low Timeout If the SCL line is held low by a slave device on the bus, no further communication is possible. Furthermore, the master cannot force the SCL line high to correct the error condition. To solve this problem, the SMBus protocol specifies that devices participating in a transfer must detect any clock cycle held low longer than 25 ms as a "timeout" condition. Devices that have detected the timeout condition must reset the communication no later than 10 ms after detecting the timeout condition. When the SMBTOE bit in SMB0CF is set, Timer 3 is used to detect SCL low timeouts. Timer 3 is forced to reload when SCL is high, and allowed to count when SCL is low. With Timer 3 enabled and configured to overflow after 25 ms (and SMBTOE set), the Timer 3 interrupt service routine can be used to reset (disable and re-enable) the SMBus in the event of an SCL low timeout. 17.3.4. SCL High (SMBus Free) Timeout The SMBus specification stipulates that if the SCL and SDA lines remain high for more that 50 s, the bus is designated as free. When the SMBFTE bit in SMB0CF is set, the bus will be considered free if SCL and SDA remain high for more than 10 SMBus clock source periods. If the SMBus is waiting to generate a Master START, the START will be generated following this timeout. Note that a clock source is required for free timeout detection, even in a slave-only implementation. 17.4. Using the SMBus The SMBus can operate in both Master and Slave modes. The interface provides timing and shifting control for serial transfers; higher level protocol is determined by user software. The SMBus interface provides the following application-independent features: * * * * * * * Byte-wise serial data transfers Clock signal generation on SCL (Master Mode only) and SDA data synchronization Timeout/bus error recognition, as defined by the SMB0CF configuration register START/STOP timing, detection, and generation Bus arbitration Interrupt generation Status information SMBus interrupts are generated for each data byte or slave address that is transferred. When transmitting, this interrupt is generated after the ACK cycle so that software may read the received ACK value; when receiving data, this interrupt is generated before the ACK cycle so that software may define the outgoing ACK value. See Section "17.5. SMBus Transfer Modes" on page 204 for more details on transmission sequences. Interrupts are also generated to indicate the beginning of a transfer when a master (START generated), or the end of a transfer when a slave (STOP detected). Software should read the SMB0CN (SMBus Control register) to find the cause of the SMBus interrupt. The SMB0CN register is described in Section "17.4.2. SMB0CN Control Register" on page 201; Table 17.4 provides a quick SMB0CN decoding reference. 196 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SMBus configuration options include: * * * * Timeout detection (SCL Low Timeout and/or Bus Free Timeout) SDA setup and hold time extensions Slave event enable/disable Clock source selection These options are selected in the SMB0CF register, as described in Section "17.4.1. SMBus Configuration Register" on page 198. Rev. 0.5 197 C8051F340/1/2/3/4/5/6/7 17.4.1. SMBus Configuration Register The SMBus Configuration register (SMB0CF) is used to enable the SMBus Master and/or Slave modes, select the SMBus clock source, and select the SMBus timing and timeout options. When the ENSMB bit is set, the SMBus is enabled for all master and slave events. Slave events may be disabled by setting the INH bit. With slave events inhibited, the SMBus interface will still monitor the SCL and SDA pins; however, the interface will NACK all received addresses and will not generate any slave interrupts. When the INH bit is set, all slave events will be inhibited following the next START (interrupts will continue for the duration of the current transfer). Table 17.1. SMBus Clock Source Selection SMBCS1 0 0 1 1 SMBCS0 0 1 0 1 SMBus Clock Source Timer 0 Overflow Timer 1 Overflow Timer 2 High Byte Overflow Timer 2 Low Byte Overflow The SMBCS1-0 bits select the SMBus clock source, which is used only when operating as a master or when the Free Timeout detection is enabled. When operating as a master, overflows from the selected source determine the absolute minimum SCL low and high times as defined in Equation 17.1. Note that the selected clock source may be shared by other peripherals so long as the timer is left running at all times. For example, Timer 1 overflows may generate the SMBus and UART baud rates simultaneously. Timer configuration is covered in Section "21. Timers" on page 243. 1 T HighMin = T LowMin = --------------------------------------------f ClockSourceOverflow Equation 17.1. Minimum SCL High and Low Times The selected clock source should be configured to establish the minimum SCL High and Low times as per Equation 17.1. When the interface is operating as a master (and SCL is not driven or extended by any other devices on the bus), the typical SMBus bit rate is approximated by Equation 17.2. f ClockSourceOverflow BitRate = --------------------------------------------3 Equation 17.2. Typical SMBus Bit Rate 198 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Figure 17.4 shows the typical SCL generation described by Equation 17.2. Notice that THIGH is typically twice as large as TLOW. The actual SCL output may vary due to other devices on the bus (SCL may be extended low by slower slave devices, or driven low by contending master devices). The bit rate when operating as a master will never exceed the limits defined by equation Equation 17.1. Timer Source Overflows SCL TLow THigh SCL High Timeout Figure 17.4. Typical SMBus SCL Generation Setting the EXTHOLD bit extends the minimum setup and hold times for the SDA line. The minimum SDA setup time defines the absolute minimum time that SDA is stable before SCL transitions from low-to-high. The minimum SDA hold time defines the absolute minimum time that the current SDA value remains stable after SCL transitions from high-to-low. EXTHOLD should be set so that the minimum setup and hold times meet the SMBus Specification requirements of 250 ns and 300 ns, respectively. Table 17.2 shows the minimum setup and hold times for the two EXTHOLD settings. Setup and hold time extensions are typically necessary when SYSCLK is above 10 MHz. Table 17.2. Minimum SDA Setup and Hold Times EXTHOLD 0 1 Minimum SDA Setup Time Tlow - 4 system clocks OR 1 system clock + s/w delay* 11 system clocks Minimum SDA Hold Time 3 system clocks 12 system clocks *Note: Setup Time for ACK bit transmissions and the MSB of all data transfers. The s/w delay occurs between the time SMB0DAT or ACK is written and when SI is cleared. Note that if SI is cleared in the same write that defines the outgoing ACK value, s/w delay is zero. With the SMBTOE bit set, Timer 3 should be configured to overflow after 25 ms in order to detect SCL low timeouts (see Section "17.3.3. SCL Low Timeout" on page 196). The SMBus interface will force Timer 3 to reload while SCL is high, and allow Timer 3 to count when SCL is low. The Timer 3 interrupt service routine should be used to reset SMBus communication by disabling and re-enabling the SMBus. SMBus Free Timeout detection can be enabled by setting the SMBFTE bit. When this bit is set, the bus will be considered free if SDA and SCL remain high for more than 10 SMBus clock source periods (see Figure 17.4). When a Free Timeout is detected, the interface will respond as if a STOP was detected (an interrupt will be generated, and STO will be set). Rev. 0.5 199 C8051F340/1/2/3/4/5/6/7 SFR Definition 17.1. SMB0CF: SMBus Clock/Configuration R/W R/W R R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 SFR Address: 0xC1 Reset Value ENSMB Bit7 INH Bit6 BUSY Bit5 EXTHOLD SMBTOE SMBFTE SMBCS1 SMBCS0 00000000 ENSMB: SMBus Enable. This bit enables/disables the SMBus interface. When enabled, the interface constantly monitors the SDA and SCL pins. 0: SMBus interface disabled. 1: SMBus interface enabled. Bit6: INH: SMBus Slave Inhibit. When this bit is set to logic 1, the SMBus does not generate an interrupt when slave events occur. This effectively removes the SMBus slave from the bus. Master Mode interrupts are not affected. 0: SMBus Slave Mode enabled. 1: SMBus Slave Mode inhibited. Bit5: BUSY: SMBus Busy Indicator. This bit is set to logic 1 by hardware when a transfer is in progress. It is cleared to logic 0 when a STOP or free-timeout is sensed. Bit4: EXTHOLD: SMBus Setup and Hold Time Extension Enable. This bit controls the SDA setup and hold times according to. 0: SDA Extended Setup and Hold Times disabled. 1: SDA Extended Setup and Hold Times enabled. Bit3: SMBTOE: SMBus SCL Timeout Detection Enable. This bit enables SCL low timeout detection. If set to logic 1, the SMBus forces Timer 3 to reload while SCL is high and allows Timer 3 to count when SCL goes low. Timer 3 should be programmed to generate interrupts at 25 ms, and the Timer 3 interrupt service routine should reset SMBus communication. Bit2: SMBFTE: SMBus Free Timeout Detection Enable. When this bit is set to logic 1, the bus will be considered free if SCL and SDA remain high for more than 10 SMBus clock source periods. Bits1-0: SMBCS1-SMBCS0: SMBus Clock Source Selection. These two bits select the SMBus clock source, which is used to generate the SMBus bit rate. The selected device should be configured according to Equation 17.1. Bit7: SMBCS1 0 0 1 1 SMBCS0 0 1 0 1 SMBus Clock Source Timer 0 Overflow Timer 1 Overflow Timer 2 High Byte Overflow Timer 2 Low Byte Overflow 200 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 17.4.2. SMB0CN Control Register SMB0CN is used to control the interface and to provide status information (see SFR Definition 17.2). The higher four bits of SMB0CN (MASTER, TXMODE, STA, and STO) form a status vector that can be used to jump to service routines. MASTER and TXMODE indicate the master/slave state and transmit/receive modes, respectively. STA and STO indicate that a START and/or STOP has been detected or generated since the last SMBus interrupt. STA and STO are also used to generate START and STOP conditions when operating as a master. Writing a `1' to STA will cause the SMBus interface to enter Master Mode and generate a START when the bus becomes free (STA is not cleared by hardware after the START is generated). Writing a `1' to STO while in Master Mode will cause the interface to generate a STOP and end the current transfer after the next ACK cycle. If STO and STA are both set (while in Master Mode), a STOP followed by a START will be generated. As a receiver, writing the ACK bit defines the outgoing ACK value; as a transmitter, reading the ACK bit indicates the value received on the last ACK cycle. ACKRQ is set each time a byte is received, indicating that an outgoing ACK value is needed. When ACKRQ is set, software should write the desired outgoing value to the ACK bit before clearing SI. A NACK will be generated if software does not write the ACK bit before clearing SI. SDA will reflect the defined ACK value immediately following a write to the ACK bit; however SCL will remain low until SI is cleared. If a received slave address is not acknowledged, further slave events will be ignored until the next START is detected. The ARBLOST bit indicates that the interface has lost an arbitration. This may occur anytime the interface is transmitting (master or slave). A lost arbitration while operating as a slave indicates a bus error condition. ARBLOST is cleared by hardware each time SI is cleared. The SI bit (SMBus Interrupt Flag) is set at the beginning and end of each transfer, after each byte frame, or when an arbitration is lost; see Table 17.3 for more details. Important Note About the SI Bit: The SMBus interface is stalled while SI is set; thus SCL is held low, and the bus is stalled until software clears SI. Table 17.3 lists all sources for hardware changes to the SMB0CN bits. Refer to Table 17.4 for SMBus status decoding using the SMB0CN register. Rev. 0.5 201 C8051F340/1/2/3/4/5/6/7 SFR Definition 17.2. SMB0CN: SMBus Control R R R/W R/W R R R/W R/W Reset Value MASTER TXMODE Bit7 Bit6 STA Bit5 STO Bit4 ACKRQ ARBLOST Bit3 Bit2 ACK Bit1 SI Bit0 00000000 Bit Addressable SFR Address: 0xC0 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: MASTER: SMBus Master/Slave Indicator. This read-only bit indicates when the SMBus is operating as a master. 0: SMBus operating in Slave Mode. 1: SMBus operating in Master Mode. TXMODE: SMBus Transmit Mode Indicator. This read-only bit indicates when the SMBus is operating as a transmitter. 0: SMBus in Receiver Mode. 1: SMBus in Transmitter Mode. STA: SMBus Start Flag. Write: 0: No Start generated. 1: When operating as a master, a START condition is transmitted if the bus is free (If the bus is not free, the START is transmitted after a STOP is received or a timeout is detected). If STA is set by software as an active Master, a repeated START will be generated after the next ACK cycle. Read: 0: No Start or repeated Start detected. 1: Start or repeated Start detected. STO: SMBus Stop Flag. Write: 0: No STOP condition is transmitted. 1: Setting STO to logic 1 causes a STOP condition to be transmitted after the next ACK cycle. When the STOP condition is generated, hardware clears STO to logic 0. If both STA and STO are set, a STOP condition is transmitted followed by a START condition. Read: 0: No Stop condition detected. 1: Stop condition detected (if in Slave Mode) or pending (if in Master Mode). ACKRQ: SMBus Acknowledge Request This read-only bit is set to logic 1 when the SMBus has received a byte and needs the ACK bit to be written with the correct ACK response value. ARBLOST: SMBus Arbitration Lost Indicator. This read-only bit is set to logic 1 when the SMBus loses arbitration while operating as a transmitter. A lost arbitration while a slave indicates a bus error condition. ACK: SMBus Acknowledge Flag. This bit defines the out-going ACK level and records incoming ACK levels. It should be written each time a byte is received (when ACKRQ=1), or read after each byte is transmitted. 0: A "not acknowledge" has been received (if in Transmitter Mode) OR will be transmitted (if in Receiver Mode). 1: An "acknowledge" has been received (if in Transmitter Mode) OR will be transmitted (if in Receiver Mode). SI: SMBus Interrupt Flag. This bit is set by hardware under the conditions listed in Table 17.3. SI must be cleared by software. While SI is set, SCL is held low and the SMBus is stalled. 202 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 17.3. Sources for Hardware Changes to SMB0CN Bit MASTER Set by Hardware When: * A START is generated. * START is generated. * SMB0DAT is written before the start of an SMBus frame. * A START followed by an address byte is received. * A STOP is detected while addressed as a slave. * Arbitration is lost due to a detected STOP. * A byte has been received and an ACK response value is needed. * A repeated START is detected as a MASTER when STA is low (unwanted repeated START). * SCL is sensed low while attempting to generate a STOP or repeated START condition. * SDA is sensed low while transmitting a `1' (excluding ACK bits). * The incoming ACK value is low (ACKNOWLEDGE). * A START has been generated. * Lost arbitration. * A byte has been transmitted and an ACK/ NACK received. * A byte has been received. * A START or repeated START followed by a slave address + R/W has been received. * A STOP has been received. TXMODE STA STO ACKRQ Cleared by Hardware When: * A STOP is generated. * Arbitration is lost. * A START is detected. * Arbitration is lost. * SMB0DAT is not written before the start of an SMBus frame. * Must be cleared by software. * A pending STOP is generated. * After each ACK cycle. * Each time SI is cleared. ARBLOST ACK * The incoming ACK value is high (NOT ACKNOWLEDGE). * Must be cleared by software. SI Rev. 0.5 203 C8051F340/1/2/3/4/5/6/7 17.4.3. Data Register The SMBus Data register SMB0DAT holds a byte of serial data to be transmitted or one that has just been received. Software may safely read or write to the data register when the SI flag is set. Software should not attempt to access the SMB0DAT register when the SMBus is enabled and the SI flag is cleared to logic 0, as the interface may be in the process of shifting a byte of data into or out of the register. Data in SMB0DAT is always shifted out MSB first. After a byte has been received, the first bit of received data is located at the MSB of SMB0DAT. While data is being shifted out, data on the bus is simultaneously being shifted in. SMB0DAT always contains the last data byte present on the bus. In the event of lost arbitration, the transition from master transmitter to slave receiver is made with the correct data or address in SMB0DAT. SFR Definition 17.3. SMB0DAT: SMBus Data R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 SFR Address: 0xC2 Reset Value 00000000 Bits7-0: SMB0DAT: SMBus Data. The SMB0DAT register contains a byte of data to be transmitted on the SMBus serial interface or a byte that has just been received on the SMBus serial interface. The CPU can read from or write to this register whenever the SI serial interrupt flag (SMB0CN.0) is set to logic 1. The serial data in the register remains stable as long as the SI flag is set. When the SI flag is not set, the system may be in the process of shifting data in/out and the CPU should not attempt to access this register. 17.5. SMBus Transfer Modes The SMBus interface may be configured to operate as master and/or slave. At any particular time, it will be operating in one of the following four modes: Master Transmitter, Master Receiver, Slave Transmitter, or Slave Receiver. The SMBus interface enters Master Mode any time a START is generated, and remains in Master Mode until it loses an arbitration or generates a STOP. An SMBus interrupt is generated at the end of all SMBus byte frames; however, note that the interrupt is generated before the ACK cycle when operating as a receiver, and after the ACK cycle when operating as a transmitter. 17.5.1. Master Transmitter Mode Serial data is transmitted on SDA while the serial clock is output on SCL. The SMBus interface generates the START condition and transmits the first byte containing the address of the target slave and the data direction bit. In this case the data direction bit (R/W) will be logic 0 (WRITE). The master then transmits one or more bytes of serial data. After each byte is transmitted, an acknowledge bit is generated by the slave. The transfer is ended when the STO bit is set and a STOP is generated. Note that the interface will switch to Master Receiver Mode if SMB0DAT is not written following a Master Transmitter interrupt. Figure 17.5 shows a typical Master Transmitter sequence. Two transmit data bytes are shown, though any number of bytes may be transmitted. Notice that the `data byte transferred' interrupts occur after the ACK cycle in this mode. 204 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 S SLA W A Data Byte A Data Byte A P Interrupt Interrupt Interrupt Interrupt Received by SMBus Interface Transmitted by SMBus Interface S = START P = STOP A = ACK W = WRITE SLA = Slave Address Figure 17.5. Typical Master Transmitter Sequence Rev. 0.5 205 C8051F340/1/2/3/4/5/6/7 17.5.2. Master Receiver Mode Serial data is received on SDA while the serial clock is output on SCL. The SMBus interface generates the START condition and transmits the first byte containing the address of the target slave and the data direction bit. In this case the data direction bit (R/W) will be logic 1 (READ). Serial data is then received from the slave on SDA while the SMBus outputs the serial clock. The slave transmits one or more bytes of serial data. After each byte is received, ACKRQ is set to `1' and an interrupt is generated. Software must write the ACK bit (SMB0CN.1) to define the outgoing acknowledge value (Note: writing a `1' to the ACK bit generates an ACK; writing a `0' generates a NACK). Software should write a `0' to the ACK bit after the last byte is received, to transmit a NACK. The interface exits Master Receiver Mode after the STO bit is set and a STOP is generated. Note that the interface will switch to Master Transmitter Mode if SMB0DAT is written while an active Master Receiver. Figure 17.6 shows a typical Master Receiver sequence. Two received data bytes are shown, though any number of bytes may be received. Notice that the `data byte transferred' interrupts occur before the ACK cycle in this mode. S SLA R A Data Byte A Data Byte N P Interrupt Interrupt Interrupt Interrupt S = START P = STOP A = ACK N = NACK R = READ SLA = Slave Address Received by SMBus Interface Transmitted by SMBus Interface Figure 17.6. Typical Master Receiver Sequence 206 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 17.5.3. Slave Receiver Mode Serial data is received on SDA and the clock is received on SCL. When slave events are enabled (INH = 0), the interface enters Slave Receiver Mode when a START followed by a slave address and direction bit (WRITE in this case) is received. Upon entering Slave Receiver Mode, an interrupt is generated and the ACKRQ bit is set. Software responds to the received slave address with an ACK, or ignores the received slave address with a NACK. If the received slave address is ignored, slave interrupts will be inhibited until the next START is detected. If the received slave address is acknowledged, zero or more data bytes are received. Software must write the ACK bit after each received byte to ACK or NACK the received byte. The interface exits Slave Receiver Mode after receiving a STOP. Note that the interface will switch to Slave Transmitter Mode if SMB0DAT is written while an active Slave Receiver. Figure 17.7 shows a typical Slave Receiver sequence. Two received data bytes are shown, though any number of bytes may be received. Notice that the `data byte transferred' interrupts occur before the ACK cycle in this mode. Interrupt S SLA W A Data Byte A Data Byte A P Interrupt Received by SMBus Interface Transmitted by SMBus Interface Interrupt Interrupt S = START P = STOP A = ACK W = WRITE SLA = Slave Address Figure 17.7. Typical Slave Receiver Sequence Rev. 0.5 207 C8051F340/1/2/3/4/5/6/7 17.5.4. Slave Transmitter Mode Serial data is transmitted on SDA and the clock is received on SCL. When slave events are enabled (INH = 0), the interface enters Slave Receiver Mode (to receive the slave address) when a START followed by a slave address and direction bit (READ in this case) is received. Upon entering Slave Transmitter Mode, an interrupt is generated and the ACKRQ bit is set. Software responds to the received slave address with an ACK, or ignores the received slave address with a NACK. If the received slave address is ignored, slave interrupts will be inhibited until a START is detected. If the received slave address is acknowledged, data should be written to SMB0DAT to be transmitted. The interface enters Slave Transmitter Mode, and transmits one or more bytes of data. After each byte is transmitted, the master sends an acknowledge bit; if the acknowledge bit is an ACK, SMB0DAT should be written with the next data byte. If the acknowledge bit is a NACK, SMB0DAT should not be written to before SI is cleared (Note: an error condition may be generated if SMB0DAT is written following a received NACK while in Slave Transmitter Mode). The interface exits Slave Transmitter Mode after receiving a STOP. Note that the interface will switch to Slave Receiver Mode if SMB0DAT is not written following a Slave Transmitter interrupt. Figure 17.8 shows a typical Slave Transmitter sequence. Two transmitted data bytes are shown, though any number of bytes may be transmitted. Notice that the `data byte transferred' interrupts occur after the ACK cycle in this mode. Interrupt S SLA R A Data Byte A Data Byte N P Interrupt Received by SMBus Interface Transmitted by SMBus Interface Interrupt Interrupt S = START P = STOP N = NACK R = READ SLA = Slave Address Figure 17.8. Typical Slave Transmitter Sequence 17.6. SMBus Status Decoding The current SMBus status can be easily decoded using the SMB0CN register. In the table below, STATUS VECTOR refers to the four upper bits of SMB0CN: MASTER, TXMODE, STA, and STO. Note that the shown response options are only the typical responses; application-specific procedures are allowed as long as they conform to the SMBus specification. Highlighted responses are allowed but do not conform to the SMBus specification. 208 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 17.4. SMBus Status Decoding Values Read Mode ARBLOST ACKRQ Status Vector Values Written ACK ACK Current SMbus State Typical Response Options STA STo 1110 0 0 0 0 X A master START was generated. 0 Load slave address + R/W into SMB0DAT. 0 1 0 0 0 1 1 0 0 0 1 1 1 0 0 1 0 1 1 0 0 0 1 1 0 0 X X X X X X X X 1 0 0 1 0 Master Transmitter Set STA to restart transfer. A master data or address byte was transmitted; NACK received. Abort transfer. Load next data byte into SMB0DAT. End transfer with STOP. 1100 0 0 1 A master data or address byte was transmitted; ACK received. End transfer with STOP and start another transfer. Send repeated START. Switch to Master Receiver Mode (clear SI without writing new data to SMB0DAT). Acknowledge received byte; Read SMB0DAT. Send NACK to indicate last byte, and send STOP. Send NACK to indicate last byte, and send STOP followed by START. Master Receiver Send ACK followed by repeated START. 1000 1 0 X A master data byte was received; Send NACK to indicate last ACK requested. byte, and send repeated START. Send ACK and switch to Master Transmitter Mode (write to SMB0DAT before clearing SI). Send NACK and switch to Master Transmitter Mode (write to SMB0DAT before clearing SI). 0 0 1 0 0 0 Rev. 0.5 209 C8051F340/1/2/3/4/5/6/7 Table 17.4. SMBus Status Decoding (Continued) Values Read Mode ARBLOST ACKRQ Status Vector Values Written ACK ACK Current SMbus State Typical Response Options STA STo Slave Transmitter 0 0100 0 0 0101 0 0 0 1 X 0 1 X X A slave byte was transmitted; NACK received. A slave byte was transmitted; ACK received. A Slave byte was transmitted; error detected. A STOP was detected while an addressed Slave Transmitter. A slave address was received; ACK requested. No action required (expecting STOP condition). Load SMB0DAT with next data byte to transmit. No action required (expecting Master to end transfer). No action required (transfer complete). Acknowledge received address. Do not acknowledge received address. Acknowledge received address. 0 0 0 0 0 0 0 0 1 0 1 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 X X X X 1 0 1 0 0 X X 0 X X X 1 0 0 0 1 0 X 0010 1 1 Lost arbitration as master; slave X address received; ACK requested. Do not acknowledge received address. Reschedule failed transfer; do not acknowledge received address. Slave Receiver 0010 0 1 1 1 0 1 X X X X Lost arbitration while attempting a Abort failed transfer. repeated START. Reschedule failed transfer. Lost arbitration while attempting a No action required (transfer STOP. complete/aborted). A STOP was detected while an addressed slave receiver. No action required (transfer complete). 0001 0 0 Lost arbitration due to a detected Abort transfer. STOP. Reschedule failed transfer. A slave byte was received; ACK requested. Acknowledge received byte; Read SMB0DAT. Do not acknowledge received byte. 1 0000 1 0 X 1 X Lost arbitration while transmitting Abort failed transfer. a data byte as master. Reschedule failed transfer. 210 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 18. UART0 UART0 is an asynchronous, full duplex serial port offering modes 1 and 3 of the standard 8051 UART. Enhanced baud rate support allows a wide range of clock sources to generate standard baud rates (details in Section "18.1. Enhanced Baud Rate Generation" on page 212). Received data buffering allows UART0 to start reception of a second incoming data byte before software has finished reading the previous data byte. UART0 has two associated SFRs: Serial Control Register 0 (SCON0) and Serial Data Buffer 0 (SBUF0). The single SBUF0 location provides access to both transmit and receive registers. Writes to SBUF0 always access the Transmit register. Reads of SBUF0 always access the buffered Receive register; it is not possible to read data from the Transmit register. With UART0 interrupts enabled, an interrupt is generated each time a transmit is completed (TI0 is set in SCON0), or a data byte has been received (RI0 is set in SCON0). The UART0 interrupt flags are not cleared by hardware when the CPU vectors to the interrupt service routine. They must be cleared manually by software, allowing software to determine the cause of the UART0 interrupt (transmit complete or receive complete). SFR Bus Write to SBUF0 TB80 SET D CLR Q SBUF0 (TX Shift) TX0 Crossbar Zero Detector Stop Bit Start Tx Clock Shift Data Tx Control Tx IRQ Send SCON S0MODE MCE0 REN0 TB80 RB80 TI0 RI0 UART0 Baud Rate Generator TI0 Serial Port Interrupt RI0 Port I/O Rx IRQ Rx Clock Rx Control Start Shift 0x1FF RB80 Load SBUF0 Input Shift Register (9 bits) Load SBUF0 SBUF0 (RX Latch) Read SBUF0 SFR Bus RX0 Crossbar Figure 18.1. UART0 Block Diagram Rev. 0.5 211 C8051F340/1/2/3/4/5/6/7 18.1. Enhanced Baud Rate Generation The UART0 baud rate is generated by Timer 1 in 8-bit auto-reload mode. The TX clock is generated by TL1; the RX clock is generated by a copy of TL1 (shown as RX Timer in Figure 18.2), which is not user-accessible. Both TX and RX Timer overflows are divided by two to generate the TX and RX baud rates. The RX Timer runs when Timer 1 is enabled, and uses the same reload value (TH1). However, an RX Timer reload is forced when a START condition is detected on the RX pin. This allows a receive to begin any time a START is detected, independent of the TX Timer state. Timer 1 TL1 Overflow UART 2 TX Clock TH1 Start Detected RX Timer Overflow 2 RX Clock Figure 18.2. UART0 Baud Rate Logic Timer 1 should be configured for Mode 2, 8-bit auto-reload (see Section "21.1.3. Mode 2: 8-bit Counter/ Timer with Auto-Reload" on page 245). The Timer 1 reload value should be set so that overflows will occur at two times the desired UART baud rate frequency. Note that Timer 1 may be clocked by one of six sources: SYSCLK, SYSCLK / 4, SYSCLK / 12, SYSCLK / 48, the external oscillator clock / 8, or an external input T1. For any given Timer 1 clock source, the UART0 baud rate is determined by Equation 18.1. T1 CLK 1 -UartBaudRate = ------------------------------ x -( 256 - T1H ) 2 Equation 18.1. UART0 Baud Rate Where T1CLK is the frequency of the clock supplied to Timer 1, and T1H is the high byte of Timer 1 (reload value). Timer 1 clock frequency is selected as described in Section "21. Timers" on page 243. A quick reference for typical baud rates using the internal oscillator is given in Table 18.1. Note that the internal oscillator may still generate the system clock if an external oscillator is driving Timer 1. 18.2. Operational Modes UART0 provides standard asynchronous, full duplex communication. The UART mode (8-bit or 9-bit) is selected by the S0MODE bit (SCON0.7). Typical UART connection options are shown below. 212 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 TX RX RS-232 RS-232 LEVEL XLTR C8051Fxxx OR TX TX MCU RX RX C8051Fxxx Figure 18.3. UART Interconnect Diagram 18.2.1. 8-Bit UART 8-Bit UART mode uses a total of 10 bits per data byte: one start bit, eight data bits (LSB first), and one stop bit. Data are transmitted LSB first from the TX0 pin and received at the RX0 pin. On receive, the eight data bits are stored in SBUF0 and the stop bit goes into RB80 (SCON0.2). Data transmission begins when software writes a data byte to the SBUF0 register. The TI0 Transmit Interrupt Flag (SCON0.1) is set at the end of the transmission (the beginning of the stop-bit time). Data reception can begin any time after the REN0 Receive Enable bit (SCON0.4) is set to logic 1. After the stop bit is received, the data byte will be loaded into the SBUF0 receive register if the following conditions are met: RI0 must be logic 0, and if MCE0 is logic 1, the stop bit must be logic 1. In the event of a receive data overrun, the first received 8 bits are latched into the SBUF0 receive register and the following overrun data bits are lost. If these conditions are met, the eight bits of data is stored in SBUF0, the stop bit is stored in RB80 and the RI0 flag is set. If these conditions are not met, SBUF0 and RB80 will not be loaded and the RI0 flag will not be set. An interrupt will occur if enabled when either TI0 or RI0 is set. MARK SPACE BIT TIMES START BIT D0 D1 D2 D3 D4 D5 D6 D7 STOP BIT BIT SAMPLING Figure 18.4. 8-Bit UART Timing Diagram Rev. 0.5 213 C8051F340/1/2/3/4/5/6/7 18.2.2. 9-Bit UART 9-bit UART mode uses a total of eleven bits per data byte: a start bit, 8 data bits (LSB first), a programmable ninth data bit, and a stop bit. The state of the ninth transmit data bit is determined by the value in TB80 (SCON0.3), which is assigned by user software. It can be assigned the value of the parity flag (bit P in register PSW) for error detection, or used in multiprocessor communications. On receive, the ninth data bit goes into RB80 (SCON0.2) and the stop bit is ignored. Data transmission begins when an instruction writes a data byte to the SBUF0 register. The TI0 Transmit Interrupt Flag (SCON0.1) is set at the end of the transmission (the beginning of the stop-bit time). Data reception can begin any time after the REN0 Receive Enable bit (SCON0.4) is set to `1'. After the stop bit is received, the data byte will be loaded into the SBUF0 receive register if the following conditions are met: (1) RI0 must be logic 0, and (2) if MCE0 is logic 1, the 9th bit must be logic 1 (when MCE0 is logic 0, the state of the ninth data bit is unimportant). If these conditions are met, the eight bits of data are stored in SBUF0, the ninth bit is stored in RB80, and the RI0 flag is set to `1'. If the above conditions are not met, SBUF0 and RB80 will not be loaded and the RI0 flag will not be set to `1'. A UART0 interrupt will occur if enabled when either TI0 or RI0 is set to `1'. MARK SPACE BIT TIMES START BIT D0 D1 D2 D3 D4 D5 D6 D7 D8 STOP BIT BIT SAMPLING Figure 18.5. 9-Bit UART Timing Diagram 18.3. Multiprocessor Communications 9-Bit UART mode supports multiprocessor communication between a master processor and one or more slave processors by special use of the ninth data bit. When a master processor wants to transmit to one or more slaves, it first sends an address byte to select the target(s). An address byte differs from a data byte in that its ninth bit is logic 1; in a data byte, the ninth bit is always set to logic 0. Setting the MCE0 bit (SCON0.5) of a slave processor configures its UART such that when a stop bit is received, the UART will generate an interrupt only if the ninth bit is logic 1 (RB80 = 1) signifying an address byte has been received. In the UART interrupt handler, software will compare the received address with the slave's own assigned 8-bit address. If the addresses match, the slave will clear its MCE0 bit to enable interrupts on the reception of the following data byte(s). Slaves that weren't addressed leave their MCE0 bits set and do not generate interrupts on the reception of the following data bytes, thereby ignoring the data. Once the entire message is received, the addressed slave resets its MCE0 bit to ignore all transmissions until it receives the next address byte. Multiple addresses can be assigned to a single slave and/or a single address can be assigned to multiple slaves, thereby enabling "broadcast" transmissions to more than one slave simultaneously. The master processor can be configured to receive all transmissions or a protocol can be implemented such that the master/slave role is temporarily reversed to enable half-duplex transmission between the original master and slave(s). 214 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Master Device RX TX Slave Device RX TX Slave Device RX TX Slave Device V+ RX TX Figure 18.6. UART Multi-Processor Mode Interconnect Diagram Rev. 0.5 215 C8051F340/1/2/3/4/5/6/7 SFR Definition 18.1. SCON0: Serial Port 0 Control R/W R R/W R/W R/W R/W R/W R/W Reset Value S0MODE Bit7 Bit6 MCE0 Bit5 REN0 Bit4 TB80 Bit3 RB80 Bit2 TI0 Bit1 RI0 Bit0 01000000 Bit Addressable SFR Address: 0x98 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: S0MODE: Serial Port 0 Operation Mode. This bit selects the UART0 Operation Mode. 0: 8-bit UART with Variable Baud Rate. 1: 9-bit UART with Variable Baud Rate. UNUSED. Read = 1b. Write = don't care. MCE0: Multiprocessor Communication Enable. The function of this bit is dependent on the Serial Port 0 Operation Mode. S0MODE = 0: Checks for valid stop bit. 0: Logic level of stop bit is ignored. 1: RI0 will only be activated if stop bit is logic level 1. S0MODE = 1: Multiprocessor Communications Enable. 0: Logic level of ninth bit is ignored. 1: RI0 is set and an interrupt is generated only when the ninth bit is logic 1. REN0: Receive Enable. This bit enables/disables the UART receiver. 0: UART0 reception disabled. 1: UART0 reception enabled. TB80: Ninth Transmission Bit. The logic level of this bit will be assigned to the ninth transmission bit in 9-bit UART Mode. It is not used in 8-bit UART Mode. Set or cleared by software as required. RB80: Ninth Receive Bit. RB80 is assigned the value of the STOP bit in Mode 0; it is assigned the value of the 9th data bit in Mode 1. TI0: Transmit Interrupt Flag. Set by hardware when a byte of data has been transmitted by UART0 (after the 8th bit in 8-bit UART Mode, or at the beginning of the STOP bit in 9-bit UART Mode). When the UART0 interrupt is enabled, setting this bit causes the CPU to vector to the UART0 interrupt service routine. This bit must be cleared manually by software. RI0: Receive Interrupt Flag. Set to `1' by hardware when a byte of data has been received by UART0 (set at the STOP bit sampling time). When the UART0 interrupt is enabled, setting this bit to `1' causes the CPU to vector to the UART0 interrupt service routine. This bit must be cleared manually by software. 216 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 18.2. SBUF0: Serial (UART0) Port Data Buffer R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 SFR Address: 0x99 Reset Value 00000000 Bits7-0: SBUF0[7:0]: Serial Data Buffer Bits 7-0 (MSB-LSB) This SFR accesses two registers; a transmit shift register and a receive latch register. When data is written to SBUF0, it goes to the transmit shift register and is held for serial transmission. Writing a byte to SBUF0 initiates the transmission. A read of SBUF0 returns the contents of the receive latch. Rev. 0.5 217 C8051F340/1/2/3/4/5/6/7 Table 18.1. Timer Settings for Standard Baud Rates Using The Internal Oscillator Target Baud Actual Baud Rate Error Baud Rate (bps) Rate (bps) 230400 230769 0.16% 115200 115385 0.16% 57600 57692 0.16% 28800 28846 0.16% 14400 14423 0.16% 9600 9615 0.16% 2400 2404 0.16% 1200 1202 0.16% 230400 230769 0.16% 115200 115385 0.16% 57600 57692 0.16% 28800 28846 0.16% 14400 14423 0.16% 9600 9615 0.16% 2400 2404 0.16% 1200 1202 0.16% 230400 230769 0.16% 115200 115385 0.16% 57600 57692 0.16% 28800 28846 0.16% 14400 14388 0.08% 9600 9615 0.16% 2400 2404 0.16% X = Don't care SYSCLK = 48 MHz SYSCLK = 24 MHz SYSCLK = 12 MHz Oscillator Divide Factor 52 104 208 416 832 1248 4992 9984 104 208 416 832 1664 2496 9984 19968 208 416 832 1664 3336 4992 19968 Timer Clock SCA1-SCA0 T1M* Timer 1 Source (pre-scale Reload select* Value (hex) SYSCLK XX 1 0xE6 SYSCLK XX 1 0xCC SYSCLK XX 1 0x98 SYSCLK XX 1 0x30 SYSCLK / 4 01 0 0x98 SYSCLK / 4 01 0 0x64 SYSCLK / 12 00 0 0x30 SYSCLK / 48 10 0 0x98 SYSCLK XX 1 0xCC SYSCLK XX 1 0x98 SYSCLK XX 1 0x30 SYSCLK / 4 01 0 0x98 SYSCLK / 4 01 0 0x30 SYSCLK / 12 00 0 0x98 SYSCLK / 48 10 0 0x98 SYSCLK / 48 10 0 0x30 SYSCLK XX 1 0x98 SYSCLK XX 1 0x30 SYSCLK / 4 01 0 0x98 SYSCLK / 4 01 0 0x30 SYSCLK / 12 00 0 0x75 SYSCLK / 12 00 0 0x30 SYSCLK / 48 10 0 0x30 *Note: SCA1-SCA0 and T1M define the Timer Clock Source. Bit definitions for these values can be found in Section 21.1. 218 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 19. UART1 (C8051F340/1/4/5 Only) UART1 is an asynchronous, full duplex serial port offering a variety of data formatting options. A dedicated baud rate generator with a 16-bit timer and selectable prescaler is included, which can generate a wide range of baud rates (details in Section "19.1. Baud Rate Generator" on page 220). A received data FIFO allows UART1 to receive up to three data bytes before data is lost and an overflow occurs. UART1 has six associated SFRs. Three are used for the Baud Rate Generator (SBCON1, SBRLH1, and SBRLL1), two are used for data formatting, control, and status functions (SCON1, SMOD1), and one is used to send and receive data (SBUF1). The single SBUF1 location provides access to both the transmit holding register and the receive FIFO. Writes to SBUF1 always access the Transmit Holding Register. Reads of SBUF1 always access the first byte of the Receive FIFO; it is not possible to read data from the Transmit Holding Register. With UART1 interrupts enabled, an interrupt is generated each time a transmit is completed (TI1 is set in SCON1), or a data byte has been received (RI1 is set in SCON1). The UART1 interrupt flags are not cleared by hardware when the CPU vectors to the interrupt service routine. They must be cleared manually by software, allowing software to determine the cause of the UART1 interrupt (transmit complete or receive complete). Note that if additional bytes are available in the Receive FIFO, the RI1 bit cannot be cleared by software. Baud Rate Generator SBRLH1 SYSCLK SBRLL1 Overflow Data Formatting SMOD1 MCE1 S1PT1 S1PT0 PE1 S1DL1 S1DL0 XBE1 SBL1 TX Logic TX Holding Register TX1 Timer (16-bit) EN Pre-Scaler (1, 4, 12, 48) SB1PS1 SB1PS0 Write to SBUF1 SBUF1 SB1RUN Control / Status SCON1 OVR1 PERR1 THRE1 REN1 TBX1 RBX1 TI1 RI1 Read of SBUF1 RX FIFO (3 Deep) RX Logic RX1 SBCON1 UART1 Interrupt Figure 19.1. UART1 Block Diagram Rev. 0.5 219 C8051F340/1/2/3/4/5/6/7 19.1. Baud Rate Generator The UART1 baud rate is generated by a dedicated 16-bit timer which runs from the controller's core clock (SYSCLK), and has prescaler options of 1, 4, 12, or 48. The timer and prescaler options combined allow for a wide selection of baud rates over many SYSCLK frequencies. The baud rate generator is configured using three registers: SBCON1, SBRLH1, and SBRLL1. The UART1 Baud Rate Generator Control Register (SBCON1, SFR Definition 19.4) enables or disables the baud rate generator, and selects the prescaler value for the timer. The baud rate generator must be enabled for UART1 to function. Registers SBRLH1 and SBRLL1 contain a 16-bit reload value for the dedicated 16-bit timer. The internal timer counts up from the reload value on every clock tick. On timer overflows (0xFFFF to 0x0000), the timer is reloaded. For reliable UART operation, it is recommended that the UART baud rate is not configured for baud rates faster than SYSCLK/16. The baud rate for UART1 is defined in Equation 19.1. SYSCLK 1-1 Baud Rate = -------------------------------------------------------------------------- x -- x --------------------( 65536 - (SBRLH1:SBRLL1) ) 2 Prescaler Equation 19.1. UART1 Baud Rate A quick reference for typical baud rates and system clock frequencies is given in Table 19.1. Table 19.1. Baud Rate Generator Settings for Standard Baud Rates Target Baud Rate (bps) 230400 115200 57600 28800 14400 9600 2400 1200 230400 115200 57600 28800 14400 9600 2400 1200 230400 115200 57600 28800 14400 9600 2400 1200 Actual Baud Rate (bps) 230769 115385 57692 28846 14388 9600 2400 1200 230769 115385 57692 28777 14406 9600 2400 1200 230769 115385 57554 28812 14397 9600 2400 1200 Baud Rate Error 0.16% 0.16% 0.16% 0.16% 0.08% 0.0% 0.0% 0.0% 0.16% 0.16% 0.16% 0.08% 0.04% 0.0% 0.0% 0.0% 0.16% 0.16% 0.08% 0.04% 0.02% 0.0% 0.0% 0.0% Oscillator Divide Factor 52 104 208 416 834 1250 5000 10000 104 208 416 834 1666 2500 10000 20000 208 416 834 1666 3334 5000 20000 40000 SB1PS[1:0] (Prescaler Bits) 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 Reload Value in SBRLH1:SBRLL1 0xFFE6 0xFFCC 0xFF98 0xFF30 0xFE5F 0xFD8F 0xF63C 0xEC78 0xFFCC 0xFF98 0xFF30 0xFE5F 0xFCBF 0xFB1E 0xEC78 0xD8F0 0xFF98 0xFF30 0xFE5F 0xFCBF 0xF97D 0xF63C 0xD8F0 0xB1E0 220 SYSCLK = 48 MHz SYSCLK = 24 MHz SYSCLK = 12 MHz Rev. 0.5 C8051F340/1/2/3/4/5/6/7 19.2. Data Format UART1 has a number of available options for data formatting. Data transfers begin with a start bit (logic low), followed by the data bits (sent LSB-first), a parity or extra bit (if selected), and end with one or two stop bits (logic high). The data length is variable between 5 and 8 bits. A parity bit can be appended to the data, and automatically generated and detected by hardware for even, odd, mark, or space parity. The stop bit length is selectable between short (1 bit time) and long (1.5 or 2 bit times), and a multi-processor communication mode is available for implementing networked UART buses. All of the data formatting options can be configured using the SMOD1 register, shown in SFR Definition 19.2. Figure 19.2 shows the timing for a UART1 transaction without parity or an extra bit enabled. Figure 19.3 shows the timing for a UART1 transaction with parity enabled (PE1 = 1). Figure 19.4 is an example of a UART1 transaction when the extra bit is enabled (XBE1 = 1). Note that the extra bit feature is not available when parity is enabled, and the second stop bit is only an option for data lengths of 6, 7, or 8 bits. MARK SPACE BIT TIMES START BIT D0 D1 DN-2 DN-1 STOP BIT 1 STOP BIT 2 Optional N bits; N = 5, 6, 7, or 8 Figure 19.2. UART1 Timing Without Parity or Extra Bit MARK SPACE BIT TIMES START BIT D0 D1 DN-2 DN-1 PARITY STOP BIT 1 STOP BIT 2 Optional N bits; N = 5, 6, 7, or 8 Figure 19.3. UART1 Timing With Parity MARK SPACE BIT TIMES START BIT D0 D1 DN-2 DN-1 EXTRA STOP BIT 1 STOP BIT 2 Optional N bits; N = 5, 6, 7, or 8 Figure 19.4. UART1 Timing With Extra Bit Rev. 0.5 221 C8051F340/1/2/3/4/5/6/7 19.3. Configuration and Operation UART1 provides standard asynchronous, full duplex communication. It can operate in a point-to-point serial communications application, or as a node on a multi-processor serial interface. To operate in a point-to-point application, where there are only two devices on the serial bus, the MCE1 bit in SMOD1 should be cleared to `0'. For operation as part of a multi-processor communications bus, the MCE1 and XBE1 bits should both be set to `1'. In both types of applications, data is transmitted from the microcontroller on the TX1 pin, and received on the RX1 pin. The TX1 and RX1 pins are configured using the crossbar and the Port I/O registers, as detailed in Section "15. Port Input/Output" on page 147. In typical UART communications, The transmit (TX) output of one device is connected to the receive (RX) input of the other device, either directly or through a bus transceiver, as shown in Figure 19.5. PC COM Port RS-232 RS-232 LEVEL TRANSLATOR TX RX C8051Fxxx OR TX TX MCU RX RX C8051Fxxx Figure 19.5. Typical UART Interconnect Diagram 19.3.1. Data Transmission Data transmission is double-buffered, and begins when software writes a data byte to the SBUF1 register. Writing to SBUF1 places data in the Transmit Holding Register, and the Transmit Holding Register Empty flag (THRE1) will be cleared to `0'. If the UARTs shift register is empty (i.e. no transmission is in progress) the data will be placed in the shift register, and the THRE1 bit will be set to `1'. If a transmission is in progress, the data will remain in the Transmit Holding Register until the current transmission is complete. The TI1 Transmit Interrupt Flag (SCON1.1) will be set at the end of any transmission (the beginning of the stop-bit time). If enabled, an interrupt will occur when TI1 is set. If the extra bit function is enabled (XBE1 = `1') and the parity function is disabled (PE1 = `0'), the value of the TBX1 (SCON1.3) bit will be sent in the extra bit position. When the parity function is enabled (PE1 = `1'), hardware will generate the parity bit according to the selected parity type (selected with S1PT[1:0]), and append it to the data field. Note: when parity is enabled, the extra bit function is not available. 19.3.2. Data Reception Data reception can begin any time after the REN1 Receive Enable bit (SCON1.4) is set to logic 1. After the stop bit is received, the data byte will be stored in the receive FIFO if the following conditions are met: the receive FIFO (3 bytes deep) must not be full, and the stop bit(s) must be logic 1. In the event that the receive FIFO is full, the incoming byte will be lost, and a Receive FIFO Overrun Error will be generated (OVR1 in register SCON1 will be set to logic 1). If the stop bit(s) were logic 0, the incoming data will not be stored in the receive FIFO. If the reception conditions are met, the data is stored in the receive FIFO, and the RI1 flag will be set. Note: when MCE1 = `1', RI1 will only be set if the extra bit was equal to `1'. Data can be read from the receive FIFO by reading the SBUF1 register. The SBUF1 register represents the oldest 222 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 byte in the FIFO. After SBUF1 is read, the next byte in the FIFO is loaded into SBUF1, and space is made available in the FIFO for another incoming byte. If enabled, an interrupt will occur when RI1 is set. If the extra bit function is enabled (XBE1 = `1') and the parity function is disabled (PE1 = `0'), the extra bit for the oldest byte in the FIFO can be read from the RBX1 bit (SCON1.2). If the extra bit function is not enabled, the value of the stop bit for the oldest FIFO byte will be presented in RBX1. When the parity function is enabled (PE1 = `1'), hardware will check the received parity bit against the selected parity type (selected with S1PT[1:0]) when receiving data. If a byte with parity error is received, the PERR1 flag will be set to `1'. This flag must be cleared by software. Note: when parity is enabled, the extra bit function is not available. 19.3.3. Multiprocessor Communications UART1 supports multiprocessor communication between a master processor and one or more slave processors by special use of the extra data bit. When a master processor wants to transmit to one or more slaves, it first sends an address byte to select the target(s). An address byte differs from a data byte in that its extra bit is logic 1; in a data byte, the extra bit is always set to logic 0. Setting the MCE1 bit (SMOD1.7) of a slave processor configures its UART such that when a stop bit is received, the UART will generate an interrupt only if the extra bit is logic 1 (RBX1 = 1) signifying an address byte has been received. In the UART interrupt handler, software will compare the received address with the slave's own assigned address. If the addresses match, the slave will clear its MCE1 bit to enable interrupts on the reception of the following data byte(s). Slaves that weren't addressed leave their MCE1 bits set and do not generate interrupts on the reception of the following data bytes, thereby ignoring the data. Once the entire message is received, the addressed slave resets its MCE1 bit to ignore all transmissions until it receives the next address byte. Multiple addresses can be assigned to a single slave and/or a single address can be assigned to multiple slaves, thereby enabling "broadcast" transmissions to more than one slave simultaneously. The master processor can be configured to receive all transmissions or a protocol can be implemented such that the master/slave role is temporarily reversed to enable half-duplex transmission between the original master and slave(s). Master Device RX TX Slave Device RX TX Slave Device RX TX Slave Device V+ RX TX Figure 19.6. UART Multi-Processor Mode Interconnect Diagram Rev. 0.5 223 C8051F340/1/2/3/4/5/6/7 SFR Definition 19.1. SCON1: UART1 Control R/W R/W R R/W R/W R/W R/W R/W Reset Value OVR1 Bit7 PERR1 Bit6 THRE1 Bit5 REN1 Bit4 TBX1 Bit3 RBX1 Bit2 TI1 Bit1 RI1 Bit0 00100000 Bit Addressable SFR Address: 0xD2 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: OVR1: Receive FIFO Overrun Flag. This bit is used to indicate a receive FIFO overrun condition. 0: Receive FIFO Overrun has not occurred. 1: Receive FIFO Overrun has occurred (an incoming character was discarded due to a full FIFO). This bit must be cleared to `0' by software. PERR1: Parity Error Flag. When parity is enabled, this bit is used to indicate that a parity error has occurred. It is set to `1' when the parity of the oldest byte in the FIFO does not match the selected Parity Type. 0: Parity Error has not occurred. 1: Parity Error has occurred. This bit must be cleared to `0' by software. THRE1: Transmit Holding Register Empty Flag. 0: Transmit Holding Register not Empty - do not write to SBUF1. 1: Transmit Holding Register Empty - it is safe to write to SBUF1. REN1: Receive Enable. This bit enables/disables the UART receiver. When disabled, bytes can still be read from the receive FIFO. 0: UART1 reception disabled. 1: UART1 reception enabled. TBX1: Extra Transmission Bit. The logic level of this bit will be assigned to the extra transmission bit when XBE1 is set to `1'. This bit is not used when Parity is enabled. RBX1: Extra Receive Bit. RBX1 is assigned the value of the extra bit when XBE1 is set to `1'. If XBE1 is cleared to `0', RBX1 will be assigned the logic level of the first stop bit. This bit is not valid when Parity is enabled. TI1: Transmit Interrupt Flag. Set to a `1' by hardware after data has been transmitted, at the beginning of the STOP bit. When the UART1 interrupt is enabled, setting this bit causes the CPU to vector to the UART1 interrupt service routine. This bit must be cleared manually by software. RI1: Receive Interrupt Flag. Set to `1' by hardware when a byte of data has been received by UART1 (set at the STOP bit sampling time). When the UART1 interrupt is enabled, setting this bit to `1' causes the CPU to vector to the UART1 interrupt service routine. This bit must be cleared manually by software. 224 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 19.2. SMOD1: UART1 Mode R/W R/W R/W R/W R/W R/W R/W R/W Reset Value MCE1 Bit7 S1PT1 Bit6 S1PT0 Bit5 PE1 Bit4 S1DL1 Bit3 S1DL0 Bit2 XBE1 Bit1 SBL1 Bit0 00001100 Bit Addressable SFR Address: 0xE5 MCE1: Multiprocessor Communication Enable. 0: RI will be activated if stop bit(s) are `1'. 1: RI will be activated if stop bit(s) and extra bit are `1' (extra bit must be enabled using XBE1). Note: This function is not available when hardware parity is enabled. Bits6-5: S1PT[1:0]: Parity Type. 00: Odd 01: Even 10: Mark 11: Space Bit4: PE1: Parity Enable. This bit activates hardware parity generation and checking. The parity type is selected by bits S1PT1-0 when parity is enabled. 0: Hardware parity is disabled. 1: Hardware parity is enabled. Bits3-2: S1DL[1:0]: Data Length. 00: 5-bit data 01: 6-bit data 10: 7-bit data 11: 8-bit data Bit1: XBE1: Extra Bit Enable When enabled, the value of TBX1 will be appended to the data field. 0: Extra Bit Disabled. 1: Extra Bit Enabled. Bit0: SBL1: Stop Bit Length 0: Short - Stop bit is active for one bit time. 1: Long - Stop bit is active for two bit times (data length = 6, 7, or 8 bits), or 1.5 bit times (data length = 5 bits). Bit7: Rev. 0.5 225 C8051F340/1/2/3/4/5/6/7 SFR Definition 19.3. SBUF1: UART1 Data Buffer R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 SFR Address: 0xD3 Reset Value 00000000 Bits7-0: SBUF1[7:0]: Serial Data Buffer Bits 7-0 (MSB-LSB) This SFR is used to both send data from the UART and to read received data from the UART1 receive FIFO. Write: Writing a byte to SBUF1 initiates the transmission. When data is written to SBUF1, it first goes to the Transmit Holding Register, where it is held for serial transmission. When the transmit shift register is available, data is transferred into the shift register, and SBUF1 may be written again. Read: Reading SBUF1 retrieves data from the receive FIFO. When read, the oldest byte in the receive FIFO is returned, and removed from the FIFO. Up to three bytes may be held in the FIFO. If there are additional bytes available in the FIFO, the RI1 bit will remain at logic `1', even after being cleared by software. SFR Definition 19.4. SBCON1: UART1 Baud Rate Generator Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value Reserved SB1RUN Reserved Reserved Reserved Reserved SB1PS1 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 SB1PS0 Bit0 00000000 Bit Addressable SFR Address: 0xAC Bit7: Bit6: RESERVED: Read = 0b; Must write 0b. SB1RUN: Baud Rate Generator Enable. 0: Baud Rate Generator is disabled. UART1 will not function. 1: Baud Rate Generator is enabled. Bits5-2: RESERVED: Read = 0000b; Must write 0000b. Bits1-0: SB1PS[1:0]: Baud Rate Prescaler Select. 00: Prescaler = 12 01: Prescaler = 4 10: Prescaler = 48 11: Prescaler = 1 226 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 19.5. SBRLH1: UART1 Baud Rate Generator High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 SFR Address: 0xB5 Reset Value 00000000 Bits7-0: SBRLH1[7:0]: High Byte of reload value for UART1 Baud Rate Generator. SFR Definition 19.6. SBRLL1: UART1 Baud Rate Generator Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 SFR Address: 0xB4 Reset Value 00000000 Bits7-0: SBRLL1[7:0]: Low Byte of reload value for UART1 Baud Rate Generator. Rev. 0.5 227 C8051F340/1/2/3/4/5/6/7 NOTES: 228 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 20. Enhanced Serial Peripheral Interface (SPI0) The Enhanced Serial Peripheral Interface (SPI0) provides access to a flexible, full-duplex synchronous serial bus. SPI0 can operate as a master or slave device in both 3-wire or 4-wire modes, and supports multiple masters and slaves on a single SPI bus. The slave-select (NSS) signal can be configured as an input to select SPI0 in slave mode, or to disable Master Mode operation in a multi-master environment, avoiding contention on the SPI bus when more than one master attempts simultaneous data transfers. NSS can also be configured as a chip-select output in master mode, or disabled for 3-wire operation. Additional general purpose port I/O pins can be used to select multiple slave devices in master mode. SFR Bus SPI0CKR SCR7 SCR6 SCR5 SCR4 SCR3 SCR2 SCR1 SCR0 SPI0CFG SPIBSY MSTEN CKPHA CKPOL SLVSEL NSSIN SRMT RXBMT SPI0CN SPIF WCOL MODF RXOVRN NSSMD1 NSSMD0 TXBMT SPIEN SYSCLK Clock Divide Logic SPI CONTROL LOGIC Data Path Control Pin Interface Control SPI IRQ Tx Data MOSI SPI0DAT Transmit Data Buffer Pin Control Logic SCK Shift Register 76543210 Rx Data MISO C R O S S B A R Port I/O Receive Data Buffer NSS Write SPI0DAT Read SPI0DAT SFR Bus Figure 20.1. SPI Block Diagram Rev. 0.5 229 C8051F340/1/2/3/4/5/6/7 20.1. Signal Descriptions The four signals used by SPI0 (MOSI, MISO, SCK, NSS) are described below. 20.1.1. Master Out, Slave In (MOSI) The master-out, slave-in (MOSI) signal is an output from a master device and an input to slave devices. It is used to serially transfer data from the master to the slave. This signal is an output when SPI0 is operating as a master and an input when SPI0 is operating as a slave. Data is transferred most-significant bit first. When configured as a master, MOSI is driven by the MSB of the shift register in both 3- and 4-wire mode. 20.1.2. Master In, Slave Out (MISO) The master-in, slave-out (MISO) signal is an output from a slave device and an input to the master device. It is used to serially transfer data from the slave to the master. This signal is an input when SPI0 is operating as a master and an output when SPI0 is operating as a slave. Data is transferred most-significant bit first. The MISO pin is placed in a high-impedance state when the SPI module is disabled and when the SPI operates in 4-wire mode as a slave that is not selected. When acting as a slave in 3-wire mode, MISO is always driven by the MSB of the shift register. 20.1.3. Serial Clock (SCK) The serial clock (SCK) signal is an output from the master device and an input to slave devices. It is used to synchronize the transfer of data between the master and slave on the MOSI and MISO lines. SPI0 generates this signal when operating as a master. The SCK signal is ignored by a SPI slave when the slave is not selected (NSS = 1) in 4-wire slave mode. 20.1.4. Slave Select (NSS) The function of the slave-select (NSS) signal is dependent on the setting of the NSSMD1 and NSSMD0 bits in the SPI0CN register. There are three possible modes that can be selected with these bits: 1. NSSMD[1:0] = 00: 3-Wire Master or 3-Wire Slave Mode: SPI0 operates in 3-wire mode, and NSS is disabled. When operating as a slave device, SPI0 is always selected in 3-wire mode. Since no select signal is present, SPI0 must be the only slave on the bus in 3-wire mode. This is intended for point-to-point communication between a master and one slave. 2. NSSMD[1:0] = 01: 4-Wire Slave or Multi-Master Mode: SPI0 operates in 4-wire mode, and NSS is enabled as an input. When operating as a slave, NSS selects the SPI0 device. When operating as a master, a 1-to-0 transition of the NSS signal disables the master function of SPI0 so that multiple master devices can be used on the same SPI bus. 3. NSSMD[1:0] = 1x: 4-Wire Master Mode: SPI0 operates in 4-wire mode, and NSS is enabled as an output. The setting of NSSMD0 determines what logic level the NSS pin will output. This configuration should only be used when operating SPI0 as a master device. See Figure 20.2, Figure 20.3, and Figure 20.4 for typical connection diagrams of the various operational modes. Note that the setting of NSSMD bits affects the pinout of the device. When in 3-wire master or 3-wire slave mode, the NSS pin will not be mapped by the crossbar. In all other modes, the NSS signal will be mapped to a pin on the device. See Section "15. Port Input/Output" on page 147 for general purpose port I/O and crossbar information. 230 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 20.2. SPI0 Master Mode Operation A SPI master device initiates all data transfers on a SPI bus. SPI0 is placed in master mode by setting the Master Enable flag (MSTEN, SPI0CN.6). Writing a byte of data to the SPI0 data register (SPI0DAT) when in master mode writes to the transmit buffer. If the SPI shift register is empty, the byte in the transmit buffer is moved to the shift register, and a data transfer begins. The SPI0 master immediately shifts out the data serially on the MOSI line while providing the serial clock on SCK. The SPIF (SPI0CN.7) flag is set to logic 1 at the end of the transfer. If interrupts are enabled, an interrupt request is generated when the SPIF flag is set. While the SPI0 master transfers data to a slave on the MOSI line, the addressed SPI slave device simultaneously transfers the contents of its shift register to the SPI master on the MISO line in a full-duplex operation. Therefore, the SPIF flag serves as both a transmit-complete and receive-data-ready flag. The data byte received from the slave is transferred MSB-first into the master's shift register. When a byte is fully shifted into the register, it is moved to the receive buffer where it can be read by the processor by reading SPI0DAT. When configured as a master, SPI0 can operate in one of three different modes: multi-master mode, 3-wire single-master mode, and 4-wire single-master mode. The default, multi-master mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 1. In this mode, NSS is an input to the device, and is used to disable the master SPI0 when another master is accessing the bus. When NSS is pulled low in this mode, MSTEN (SPI0CN.6) and SPIEN (SPI0CN.0) are set to 0 to disable the SPI master device, and a Mode Fault is generated (MODF, SPI0CN.5 = 1). Mode Fault will generate an interrupt if enabled. SPI0 must be manually re-enabled in software under these circumstances. In multi-master systems, devices will typically default to being slave devices while they are not acting as the system master device. In multi-master mode, slave devices can be addressed individually (if needed) using general-purpose I/O pins. Figure 20.2 shows a connection diagram between two master devices in multiple-master mode. 3-wire single-master mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 0. In this mode, NSS is not used, and is not mapped to an external port pin through the crossbar. Any slave devices that must be addressed in this mode should be selected using general-purpose I/O pins. Figure 20.3 shows a connection diagram between a master device in 3-wire master mode and a slave device. 4-wire single-master mode is active when NSSMD1 (SPI0CN.3) = 1. In this mode, NSS is configured as an output pin, and can be used as a slave-select signal for a single SPI device. In this mode, the output value of NSS is controlled (in software) with the bit NSSMD0 (SPI0CN.2). Additional slave devices can be addressed using general-purpose I/O pins. Figure 20.4 shows a connection diagram for a master device in 4-wire master mode and two slave devices. Rev. 0.5 231 C8051F340/1/2/3/4/5/6/7 NSS GPIO MISO MOSI SCK NSS Master Device 1 MISO MOSI SCK GPIO Master Device 2 Figure 20.2. Multiple-Master Mode Connection Diagram Master Device MISO MOSI SCK MISO MOSI SCK Slave Device Figure 20.3. 3-Wire Single Master and Slave Mode Connection Diagram Master Device GPIO MISO MOSI SCK NSS MISO MOSI SCK NSS Slave Device MISO MOSI SCK NSS Slave Device Figure 20.4. 4-Wire Single Master Mode and Slave Mode Connection Diagram 232 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 20.3. SPI0 Slave Mode Operation When SPI0 is enabled and not configured as a master, it will operate as a SPI slave. As a slave, bytes are shifted in through the MOSI pin and out through the MISO pin by a master device controlling the SCK signal. A bit counter in the SPI0 logic counts SCK edges. When 8 bits have been shifted through the shift register, the SPIF flag is set to logic 1, and the byte is copied into the receive buffer. Data is read from the receive buffer by reading SPI0DAT. A slave device cannot initiate transfers. Data to be transferred to the master device is pre-loaded into the shift register by writing to SPI0DAT. Writes to SPI0DAT are double-buffered, and are placed in the transmit buffer first. If the shift register is empty, the contents of the transmit buffer will immediately be transferred into the shift register. When the shift register already contains data, the SPI will load the shift register with the transmit buffer's contents after the last SCK edge of the next (or current) SPI transfer. When configured as a slave, SPI0 can be configured for 4-wire or 3-wire operation. The default, 4-wire slave mode, is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 1. In 4-wire mode, the NSS signal is routed to a port pin and configured as a digital input. SPI0 is enabled when NSS is logic 0, and disabled when NSS is logic 1. The bit counter is reset on a falling edge of NSS. Note that the NSS signal must be driven low at least 2 system clocks before the first active edge of SCK for each byte transfer. Figure 20.4 shows a connection diagram between two slave devices in 4-wire slave mode and a master device. 3-wire slave mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 0. NSS is not used in this mode, and is not mapped to an external port pin through the crossbar. Since there is no way of uniquely addressing the device in 3-wire slave mode, SPI0 must be the only slave device present on the bus. It is important to note that in 3-wire slave mode there is no external means of resetting the bit counter that determines when a full byte has been received. The bit counter can only be reset by disabling and re-enabling SPI0 with the SPIEN bit. Figure 20.3 shows a connection diagram between a slave device in 3-wire slave mode and a master device. 20.4. SPI0 Interrupt Sources When SPI0 interrupts are enabled, the following four flags will generate an interrupt when they are set to logic 1: Note that all of the following bits must be cleared by software. 1. The SPI Interrupt Flag, SPIF (SPI0CN.7) is set to logic 1 at the end of each byte transfer. This flag can occur in all SPI0 modes. 2. The Write Collision Flag, WCOL (SPI0CN.6) is set to logic 1 if a write to SPI0DAT is attempted when the transmit buffer has not been emptied to the SPI shift register. When this occurs, the write to SPI0DAT will be ignored, and the transmit buffer will not be written.This flag can occur in all SPI0 modes. 3. The Mode Fault Flag MODF (SPI0CN.5) is set to logic 1 when SPI0 is configured as a master, and for multi-master mode and the NSS pin is pulled low. When a Mode Fault occurs, the MSTEN and SPIEN bits in SPI0CN are set to logic 0 to disable SPI0 and allow another master device to access the bus. 4. The Receive Overrun Flag RXOVRN (SPI0CN.4) is set to logic 1 when configured as a slave, and a transfer is completed and the receive buffer still holds an unread byte from a previous transfer. The new byte is not transferred to the receive buffer, allowing the previously received data byte to be read. The data byte which caused the overrun is lost. Rev. 0.5 233 C8051F340/1/2/3/4/5/6/7 20.5. Serial Clock Timing Four combinations of serial clock phase and polarity can be selected using the clock control bits in the SPI0 Configuration Register (SPI0CFG). The CKPHA bit (SPI0CFG.5) selects one of two clock phases (edge used to latch the data). The CKPOL bit (SPI0CFG.4) selects between an active-high or active-low clock. Both master and slave devices must be configured to use the same clock phase and polarity. SPI0 should be disabled (by clearing the SPIEN bit, SPI0CN.0) when changing the clock phase or polarity. The clock and data line relationships for master mode are shown in Figure 20.5. For slave mode, the clock and data relationships are shown in Figure 20.6 and Figure 20.7. The SPI0 Clock Rate Register (SPI0CKR) as shown in SFR Definition 20.3 controls the master mode serial clock frequency. This register is ignored when operating in slave mode. When the SPI is configured as a master, the maximum data transfer rate (bits/sec) is one-half the system clock frequency or 12.5 MHz, whichever is slower. When the SPI is configured as a slave, the maximum data transfer rate (bits/sec) for full-duplex operation is 1/10 the system clock frequency, provided that the master issues SCK, NSS (in 4-wire slave mode), and the serial input data synchronously with the slave's system clock. If the master issues SCK, NSS, and the serial input data asynchronously, the maximum data transfer rate (bits/sec) must be less than 1/10 the system clock frequency. In the special case where the master only wants to transmit data to the slave and does not need to receive data from the slave (i.e. half-duplex operation), the SPI slave can receive data at a maximum data transfer rate (bits/sec) of 1/4 the system clock frequency. This is provided that the master issues SCK, NSS, and the serial input data synchronously with the slave's system clock. SCK (CKPOL=0, CKPHA=0) SCK (CKPOL=0, CKPHA=1) SCK (CKPOL=1, CKPHA=0) SCK (CKPOL=1, CKPHA=1) MISO/MOSI MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 NSS (Must Remain High in Multi-Master Mode) Figure 20.5. Master Mode Data/Clock Timing 234 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SCK (CKPOL=0, CKPHA=0) SCK (CKPOL=1, CKPHA=0) MOSI MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MISO MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 NSS (4-Wire Mode) Figure 20.6. Slave Mode Data/Clock Timing (CKPHA = 0) SCK (CKPOL=0, CKPHA=1) SCK (CKPOL=1, CKPHA=1) MOSI MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MISO MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 NSS (4-Wire Mode) Figure 20.7. Slave Mode Data/Clock Timing (CKPHA = 1) Rev. 0.5 235 C8051F340/1/2/3/4/5/6/7 20.6. SPI Special Function Registers SPI0 is accessed and controlled through four special function registers in the system controller: SPI0CN Control Register, SPI0DAT Data Register, SPI0CFG Configuration Register, and SPI0CKR Clock Rate Register. The four special function registers related to the operation of the SPI0 Bus are described in the following figures. SFR Definition 20.1. SPI0CFG: SPI0 Configuration R R/W R/W R/W R R R R Reset Value SPIBSY Bit7 MSTEN Bit6 CKPHA Bit5 CKPOL Bit4 SLVSEL Bit3 NSSIN Bit2 SRMT Bit1 RXBMT 00000111 Bit0 SFR Address: 0xA1 Bit 7: Bit 6: Bit 5: Bit 4: Bit 3: Bit 2: Bit 1: Bit 0: SPIBSY: SPI Busy (read only). This bit is set to logic 1 when a SPI transfer is in progress (Master or slave Mode). MSTEN: Master Mode Enable. 0: Disable master mode. Operate in slave mode. 1: Enable master mode. Operate as a master. CKPHA: SPI0 Clock Phase. This bit controls the SPI0 clock phase. 0: Data centered on first edge of SCK period.* 1: Data centered on second edge of SCK period.* CKPOL: SPI0 Clock Polarity. This bit controls the SPI0 clock polarity. 0: SCK line low in idle state. 1: SCK line high in idle state. SLVSEL: Slave Selected Flag (read only). This bit is set to logic 1 whenever the NSS pin is low indicating SPI0 is the selected slave. It is cleared to logic 0 when NSS is high (slave not selected). This bit does not indicate the instantaneous value at the NSS pin, but rather a de-glitched version of the pin input. NSSIN: NSS Instantaneous Pin Input (read only). This bit mimics the instantaneous value that is present on the NSS port pin at the time that the register is read. This input is not de-glitched. SRMT: Shift Register Empty (Valid in Slave Mode, read only). This bit will be set to logic 1 when all data has been transferred in/out of the shift register, and there is no new information available to read from the transmit buffer or write to the receive buffer. It returns to logic 0 when a data byte is transferred to the shift register from the transmit buffer or by a transition on SCK. NOTE: SRMT = 1 when in Master Mode. RXBMT: Receive Buffer Empty (Valid in Slave Mode, read only). This bit will be set to logic 1 when the receive buffer has been read and contains no new information. If there is new information available in the receive buffer that has not been read, this bit will return to logic 0. NOTE: RXBMT = 1 when in Master Mode. *Note: In slave mode, data on MOSI is sampled in the center of each data bit. In master mode, data on MISO is sampled one SYSCLK before the end of each data bit, to provide maximum settling time for the slave device. See Table 20.1 for timing parameters. 236 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 20.2. SPI0CN: SPI0 Control R/W R/W R/W R/W R/W R/W R R/W Reset Value SPIF Bit7 WCOL Bit6 MODF Bit5 RXOVRN NSSMD1 NSSMD0 Bit4 Bit3 Bit2 TXBMT Bit1 SPIEN Bit0 00000110 Bit Addressable SFR Address: 0xF8 SPIF: SPI0 Interrupt Flag. This bit is set to logic 1 by hardware at the end of a data transfer. If interrupts are enabled, setting this bit causes the CPU to vector to the SPI0 interrupt service routine. This bit is not automatically cleared by hardware. It must be cleared by software. Bit 6: WCOL: Write Collision Flag. This bit is set to logic 1 by hardware (and generates a SPI0 interrupt) to indicate a write to the SPI0 data register was attempted when the transmit buffer was full. It must be cleared by software. Bit 5: MODF: Mode Fault Flag. This bit is set to logic 1 by hardware (and generates a SPI0 interrupt) when a master mode collision is detected (NSS is low, MSTEN = 1, and NSSMD[1:0] = 01). This bit is not automatically cleared by hardware. It must be cleared by software. Bit 4: RXOVRN: Receive Overrun Flag (Slave Mode only). This bit is set to logic 1 by hardware (and generates a SPI0 interrupt) when the receive buffer still holds unread data from a previous transfer and the last bit of the current transfer is shifted into the SPI0 shift register. This bit is not automatically cleared by hardware. It must be cleared by software. Bits 3-2: NSSMD1-NSSMD0: Slave Select Mode. Selects between the following NSS operation modes: (See Section "20.2. SPI0 Master Mode Operation" on page 231 and Section "20.3. SPI0 Slave Mode Operation" on page 233). 00: 3-Wire Slave or 3-wire Master Mode. NSS signal is not routed to a port pin. 01: 4-Wire Slave or Multi-Master Mode (Default). NSS is always an input to the device. 1x: 4-Wire Single-Master Mode. NSS signal is mapped as an output from the device and will assume the value of NSSMD0. Bit 1: TXBMT: Transmit Buffer Empty. This bit will be set to logic 0 when new data has been written to the transmit buffer. When data in the transmit buffer is transferred to the SPI shift register, this bit will be set to logic 1, indicating that it is safe to write a new byte to the transmit buffer. Bit 0: SPIEN: SPI0 Enable. This bit enables/disables the SPI. 0: SPI disabled. 1: SPI enabled. Bit 7: Rev. 0.5 237 C8051F340/1/2/3/4/5/6/7 SFR Definition 20.3. SPI0CKR: SPI0 Clock Rate R/W R/W R/W R/W R/W R/W R/W R/W Reset Value SCR7 Bit7 SCR6 Bit6 SCR5 Bit5 SCR4 Bit4 SCR3 Bit3 SCR2 Bit2 SCR1 Bit1 SCR0 00000000 Bit0 SFR Address: 0xA2 Bits 7-0: SCR7-SCR0: SPI0 Clock Rate. These bits determine the frequency of the SCK output when the SPI0 module is configured for master mode operation. The SCK clock frequency is a divided version of the system clock, and is given in the following equation, where SYSCLK is the system clock frequency and SPI0CKR is the 8-bit value held in the SPI0CKR register. SYSCLK f SCK = -----------------------------------------------2 x ( SPI0CKR + 1 ) for 0 <= SPI0CKR <= 255 Example: If SYSCLK = 2 MHz and SPI0CKR = 0x04, 2000000 f SCK = ------------------------2 x (4 + 1) f SCK = 200kHz SFR Definition 20.4. SPI0DAT: SPI0 Data R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Reset Value 00000000 Bit0 SFR Address: 0xA3 Bits 7-0: SPI0DAT: SPI0 Transmit and Receive Data. The SPI0DAT register is used to transmit and receive SPI0 data. Writing data to SPI0DAT places the data into the transmit buffer and initiates a transfer when in Master Mode. A read of SPI0DAT returns the contents of the receive buffer. 238 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SCK* T T MCKH MCKL T MIS T MIH MISO MOSI * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 20.8. SPI Master Timing (CKPHA = 0) SCK* T T MCKH MCKL T MIS T MIH MISO MOSI * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 20.9. SPI Master Timing (CKPHA = 1) Rev. 0.5 239 C8051F340/1/2/3/4/5/6/7 NSS T T T SE CKL SD SCK* T CKH T SIS T SIH MOSI T SEZ T SOH T SDZ MISO * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 20.10. SPI Slave Timing (CKPHA = 0) NSS T T T SE CKL SD SCK* T CKH T SIS T SIH MOSI T T SEZ SOH T SLH T SDZ MISO * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 20.11. SPI Slave Timing (CKPHA = 1) 240 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Table 20.1. SPI Slave Timing Parameters Parameter TMCKH TMCKL TMIS TMIH TSE TSD TSEZ TSDZ TCKH TCKL TSIS TSIH TSOH TSLH SCK High Time SCK Low Time MISO Valid to SCK Shift Edge SCK Shift Edge to MISO Change NSS Falling to First SCK Edge Last SCK Edge to NSS Rising NSS Falling to MISO Valid NSS Rising to MISO High-Z SCK High Time SCK Low Time MOSI Valid to SCK Sample Edge SCK Sample Edge to MOSI Change SCK Shift Edge to MISO Change Last SCK Edge to MISO Change (CKPHA = 1 ONLY) 6 x TSYSCLK 5 x TSYSCLK 5 x TSYSCLK 2 x TSYSCLK 2 x TSYSCLK 4 x TSYSCLK 8 x TSYSCLK Description Min 1 x TSYSCLK 1 x TSYSCLK 1 x TSYSCLK + 20 0 2 x TSYSCLK 2 x TSYSCLK Max Units ns ns ns ns ns ns Master Mode Timing* (See Figure 20.8 and Figure 20.9) Slave Mode Timing* (See Figure 20.10 and Figure 20.11) 4 x TSYSCLK 4 x TSYSCLK ns ns ns ns ns ns ns ns *Note: TSYSCLK is equal to one period of the device system clock (SYSCLK). Rev. 0.5 241 C8051F340/1/2/3/4/5/6/7 NOTES: 242 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 21. Timers Each MCU includes four counter/timers: two are 16-bit counter/timers compatible with those found in the standard 8051, and two are 16-bit auto-reload timer for use with the ADC, SMBus, USB (frame measurements), Low-Frequency Oscillator (period measurements), or for general purpose use. These timers can be used to measure time intervals, count external events and generate periodic interrupt requests. Timer 0 and Timer 1 are nearly identical and have four primary modes of operation. Timer 2 and Timer 3 offer 16-bit and split 8-bit timer functionality with auto-reload. Timer 0 and Timer 1 Modes: 13-bit counter/timer 16-bit counter/timer 8-bit counter/timer with auto-reload Two 8-bit counter/timers (Timer 0 only) Timer 2 Modes: 16-bit timer with auto-reload Two 8-bit timers with auto-reload Timer 3 Modes: 16-bit timer with auto-reload Two 8-bit timers with auto-reload Timers 0 and 1 may be clocked by one of five sources, determined by the Timer Mode Select bits (T1M-T0M) and the Clock Scale bits (SCA1-SCA0). The Clock Scale bits define a pre-scaled clock from which Timer 0 and/or Timer 1 may be clocked (See SFR Definition 21.3 for pre-scaled clock selection). Timer 0/1 may then be configured to use this pre-scaled clock signal or the system clock. Timer 2 and Timer 3 may be clocked by the system clock, the system clock divided by 12, or the external oscillator clock source divided by 8. Timer 0 and Timer 1 may also be operated as counters. When functioning as a counter, a counter/timer register is incremented on each high-to-low transition at the selected input pin (T0 or T1). Events with a frequency of up to one-fourth the system clock's frequency can be counted. The input signal need not be periodic, but it should be held at a given level for at least two full system clock cycles to ensure the level is properly sampled. 21.1. Timer 0 and Timer 1 Each timer is implemented as a 16-bit register accessed as two separate bytes: a low byte (TL0 or TL1) and a high byte (TH0 or TH1). The Counter/Timer Control register (TCON) is used to enable Timer 0 and Timer 1 as well as indicate status. Timer 0 interrupts can be enabled by setting the ET0 bit in the IE register (Section "9.3.5. Interrupt Register Descriptions" on page 89); Timer 1 interrupts can be enabled by setting the ET1 bit in the IE register (Section 9.3.5). Both counter/timers operate in one of four primary modes selected by setting the Mode Select bits T1M1-T0M0 in the Counter/Timer Mode register (TMOD). Each timer can be configured independently. Each operating mode is described below. 21.1.1. Mode 0: 13-bit Counter/Timer Timer 0 and Timer 1 operate as 13-bit counter/timers in Mode 0. The following describes the configuration and operation of Timer 0. However, both timers operate identically, and Timer 1 is configured in the same manner as described for Timer 0. The TH0 register holds the eight MSBs of the 13-bit counter/timer. TL0 holds the five LSBs in bit positions TL0.4-TL0.0. The three upper bits of TL0 (TL0.7-TL0.5) are indeterminate and should be masked out or ignored when reading. As the 13-bit timer register increments and overflows from 0x1FFF (all ones) to 0x0000, the timer overflow flag TF0 (TCON.5) is set and an interrupt will occur if Timer 0 interrupts are enabled. Rev. 0.5 243 C8051F340/1/2/3/4/5/6/7 The C/T0 bit (TMOD.2) selects the counter/timer's clock source. When C/T0 is set to logic 1, high-to-low transitions at the selected Timer 0 input pin (T0) increment the timer register (Refer to Section "15.1. Priority Crossbar Decoder" on page 149 for information on selecting and configuring external I/O pins). Clearing C/T selects the clock defined by the T0M bit (CKCON.3). When T0M is set, Timer 0 is clocked by the system clock. When T0M is cleared, Timer 0 is clocked by the source selected by the Clock Scale bits in CKCON (see SFR Definition 21.3). Setting the TR0 bit (TCON.4) enables the timer when either GATE0 (TMOD.3) is logic 0 or the input signal /INT0 is active as defined by bit IN0PL in register INT01CF (see SFR Definition 9.13). Setting GATE0 to `1' allows the timer to be controlled by the external input signal /INT0 (see Section "9.3.5. Interrupt Register Descriptions" on page 89), facilitating pulse width measurements. TR0 GATE0 0 X 1 0 1 1 1 1 X = Don't Care /INT0 X X 0 1 Counter/Timer Disabled Enabled Disabled Enabled Setting TR0 does not force the timer to reset. The timer registers should be loaded with the desired initial value before the timer is enabled. TL1 and TH1 form the 13-bit register for Timer 1 in the same manner as described above for TL0 and TH0. Timer 1 is configured and controlled using the relevant TCON and TMOD bits just as with Timer 0. The input signal /INT1 is used with Timer 1; the /INT1 polarity is defined by bit IN1PL in register INT01CF (see SFR Definition 9.13). CKCON TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 G A T E 1 C / T 1 TMOD TTG 11A MM T 10E 0 C / T 0 TT 00 MM 10 I N 1 P L INT01CF I N 1 S L 2 I N 1 S L 1 I N 1 S L 0 I N 0 P L I N 0 S L 2 I N 0 S L 1 I N 0 S L 0 Pre-scaled Clock 0 0 SYSCLK 1 1 T0 TR0 GATE0 Crossbar TCLK /INT0 IN0PL XOR Figure 21.1. T0 Mode 0 Block Diagram 21.1.2. Mode 1: 16-bit Counter/Timer Mode 1 operation is the same as Mode 0, except that the counter/timer registers use all 16 bits. The counter/timers are enabled and configured in Mode 1 in the same manner as for Mode 0. 244 Rev. 0.5 TCON TL0 (5 bits) TH0 (8 bits) TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 Interrupt C8051F340/1/2/3/4/5/6/7 21.1.3. Mode 2: 8-bit Counter/Timer with Auto-Reload Mode 2 configures Timer 0 and Timer 1 to operate as 8-bit counter/timers with automatic reload of the start value. TL0 holds the count and TH0 holds the reload value. When the counter in TL0 overflows from all ones to 0x00, the timer overflow flag TF0 (TCON.5) is set and the counter in TL0 is reloaded from TH0. If Timer 0 interrupts are enabled, an interrupt will occur when the TF0 flag is set. The reload value in TH0 is not changed. TL0 must be initialized to the desired value before enabling the timer for the first count to be correct. When in Mode 2, Timer 1 operates identically to Timer 0. Both counter/timers are enabled and configured in Mode 2 in the same manner as Mode 0. Setting the TR0 bit (TCON.4) enables the timer when either GATE0 (TMOD.3) is logic 0 or when the input signal /INT0 is active as defined by bit IN0PL in register INT01CF (see Section "9.3.2. External Interrupts" on page 87 for details on the external input signals /INT0 and /INT1). CKCON TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 G A T E 1 C / T 1 TMOD TTG 11A MM T 10E 0 C / T 0 TT 00 MM 10 I N 1 P L INT01CF I N 1 S L 2 I N 1 S L 1 I N 1 S L 0 I N 0 P L I N 0 S L 2 I N 0 S L 1 I N 0 S L 0 Pre-scaled Clock 0 0 SYSCLK 1 1 T0 TCLK TL0 (8 bits) TCON TR0 Crossbar GATE0 TH0 (8 bits) /INT0 IN0PL XOR TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 Interrupt Reload Figure 21.2. T0 Mode 2 Block Diagram Rev. 0.5 245 C8051F340/1/2/3/4/5/6/7 21.1.4. Mode 3: Two 8-bit Counter/Timers (Timer 0 Only) In Mode 3, Timer 0 is configured as two separate 8-bit counter/timers held in TL0 and TH0. The counter/ timer in TL0 is controlled using the Timer 0 control/status bits in TCON and TMOD: TR0, C/T0, GATE0 and TF0. TL0 can use either the system clock or an external input signal as its timebase. The TH0 register is restricted to a timer function sourced by the system clock or prescaled clock. TH0 is enabled using the Timer 1 run control bit TR1. TH0 sets the Timer 1 overflow flag TF1 on overflow and thus controls the Timer 1 interrupt. Timer 1 is inactive in Mode 3. When Timer 0 is operating in Mode 3, Timer 1 can be operated in Modes 0, 1 or 2, but cannot be clocked by external signals nor set the TF1 flag and generate an interrupt. However, the Timer 1 overflow can be used to generate baud rates for the SMBus and/or UART, and/or initiate ADC conversions. While Timer 0 is operating in Mode 3, Timer 1 run control is handled through its mode settings. To run Timer 1 while Timer 0 is in Mode 3, set the Timer 1 Mode as 0, 1, or 2. To disable Timer 1, configure it for Mode 3. CKCON TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 G A T E 1 C / T 1 TMOD TT 11 MM 10 G A T E 0 C / T 0 TT 00 MM 10 Pre-scaled Clock 0 TR1 TH0 (8 bits) TCON TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 Interrupt Interrupt SYSCLK 1 0 1 T0 TL0 (8 bits) TR0 Crossbar GATE0 /INT0 IN0PL XOR Figure 21.3. T0 Mode 3 Block Diagram 246 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.1. TCON: Timer Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value TF1 Bit7 TR1 Bit6 TF0 Bit5 TR0 Bit4 IE1 Bit3 IT1 Bit2 IE0 Bit1 IT0 Bit0 (bit addressable) 00000000 SFR Address: 0x88 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: TF1: Timer 1 Overflow Flag. Set by hardware when Timer 1 overflows. This flag can be cleared by software but is automatically cleared when the CPU vectors to the Timer 1 interrupt service routine. 0: No Timer 1 overflow detected. 1: Timer 1 has overflowed. TR1: Timer 1 Run Control. 0: Timer 1 disabled. 1: Timer 1 enabled. TF0: Timer 0 Overflow Flag. Set by hardware when Timer 0 overflows. This flag can be cleared by software but is automatically cleared when the CPU vectors to the Timer 0 interrupt service routine. 0: No Timer 0 overflow detected. 1: Timer 0 has overflowed. TR0: Timer 0 Run Control. 0: Timer 0 disabled. 1: Timer 0 enabled. IE1: External Interrupt 1. This flag is set by hardware when an edge/level of type defined by IT1 is detected. It can be cleared by software but is automatically cleared when the CPU vectors to the External Interrupt 1 service routine if IT1 = 1. When IT1 = 0, this flag is set to `1' when /INT1 is active as defined by bit IN1PL in register INT01CF (see SFR Definition 9.13). IT1: Interrupt 1 Type Select. This bit selects whether the configured /INT1 interrupt will be edge or level sensitive. /INT1 is configured active low or high by the IN1PL bit in the IT01CF register (see SFR Definition 9.13). 0: /INT1 is level triggered. 1: /INT1 is edge triggered. IE0: External Interrupt 0. This flag is set by hardware when an edge/level of type defined by IT0 is detected. It can be cleared by software but is automatically cleared when the CPU vectors to the External Interrupt 0 service routine if IT0 = 1. When IT0 = 0, this flag is set to `1' when /INT0 is active as defined by bit IN0PL in register INT01CF (see SFR Definition 9.13). IT0: Interrupt 0 Type Select. This bit selects whether the configured /INT0 interrupt will be edge or level sensitive. /INT0 is configured active low or high by the IN0PL bit in register IT01CF (see SFR Definition 9.13). 0: /INT0 is level triggered. 1: /INT0 is edge triggered. Rev. 0.5 247 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.2. TMOD: Timer Mode R/W R/W R/W R/W R/W R/W R/W R/W Reset Value GATE1 Bit7 C/T1 Bit6 T1M1 Bit5 T1M0 Bit4 GATE0 Bit3 C/T0 Bit2 T0M1 Bit1 T0M0 Bit0 00000000 SFR Address: 0x89 GATE1: Timer 1 Gate Control. 0: Timer 1 enabled when TR1 = 1 irrespective of /INT1 logic level. 1: Timer 1 enabled only when TR1 = 1 AND /INT1 is active as defined by bit IN1PL in register INT01CF (see SFR Definition 9.13). Bit6: C/T1: Counter/Timer 1 Select. 0: Timer Function: Timer 1 incremented by clock defined by T1M bit (CKCON.4). 1: Counter Function: Timer 1 incremented by high-to-low transitions on external input pin (T1). Bits5-4: T1M1-T1M0: Timer 1 Mode Select. These bits select the Timer 1 operation mode. Bit7: T1M1 0 0 1 1 Bit3: T1M0 0 1 0 1 Mode Mode 0: 13-bit counter/timer Mode 1: 16-bit counter/timer Mode 2: 8-bit counter/timer with auto-reload Mode 3: Timer 1 inactive GATE0: Timer 0 Gate Control. 0: Timer 0 enabled when TR0 = 1 irrespective of /INT0 logic level. 1: Timer 0 enabled only when TR0 = 1 AND /INT0 is active as defined by bit IN0PL in register INT01CF (see SFR Definition 9.13). Bit2: C/T0: Counter/Timer Select. 0: Timer Function: Timer 0 incremented by clock defined by T0M bit (CKCON.3). 1: Counter Function: Timer 0 incremented by high-to-low transitions on external input pin (T0). Bits1-0: T0M1-T0M0: Timer 0 Mode Select. These bits select the Timer 0 operation mode. T0M1 0 0 1 1 T0M0 0 1 0 1 Mode Mode 0: 13-bit counter/timer Mode 1: 16-bit counter/timer Mode 2: 8-bit counter/timer with auto-reload Mode 3: Two 8-bit counter/timers 248 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.3. CKCON: Clock Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value T3MH Bit7 T3ML Bit6 T2MH Bit5 T2ML Bit4 T1M Bit3 T0M Bit2 SCA1 Bit1 SCA0 Bit0 00000000 SFR Address: 0x8E T3MH: Timer 3 High Byte Clock Select. This bit selects the clock supplied to the Timer 3 high byte if Timer 3 is configured in split 8-bit timer mode. T3MH is ignored if Timer 3 is in any other mode. 0: Timer 3 high byte uses the clock defined by the T3XCLK bit in TMR3CN. 1: Timer 3 high byte uses the system clock. Bit6: T3ML: Timer 3 Low Byte Clock Select. This bit selects the clock supplied to Timer 3. If Timer 3 is configured in split 8-bit timer mode, this bit selects the clock supplied to the lower 8-bit timer. 0: Timer 3 low byte uses the clock defined by the T3XCLK bit in TMR3CN. 1: Timer 3 low byte uses the system clock. Bit5: T2MH: Timer 2 High Byte Clock Select. This bit selects the clock supplied to the Timer 2 high byte if Timer 2 is configured in split 8-bit timer mode. T2MH is ignored if Timer 2 is in any other mode. 0: Timer 2 high byte uses the clock defined by the T2XCLK bit in TMR2CN. 1: Timer 2 high byte uses the system clock. Bit4: T2ML: Timer 2 Low Byte Clock Select. This bit selects the clock supplied to Timer 2. If Timer 2 is configured in split 8-bit timer mode, this bit selects the clock supplied to the lower 8-bit timer. 0: Timer 2 low byte uses the clock defined by the T2XCLK bit in TMR2CN. 1: Timer 2 low byte uses the system clock. Bit3: T1M: Timer 1 Clock Select. This select the clock source supplied to Timer 1. T1M is ignored when C/T1 is set to logic 1. 0: Timer 1 uses the clock defined by the prescale bits, SCA1-SCA0. 1: Timer 1 uses the system clock. Bit2: T0M: Timer 0 Clock Select. This bit selects the clock source supplied to Timer 0. T0M is ignored when C/T0 is set to logic 1. 0: Counter/Timer 0 uses the clock defined by the prescale bits, SCA1-SCA0. 1: Counter/Timer 0 uses the system clock. Bits1-0: SCA1-SCA0: Timer 0/1 Prescale Bits. These bits control the division of the clock supplied to Timer 0 and/or Timer 1 if configured to use prescaled clock inputs. Bit7: SCA1 0 0 1 1 SCA0 0 1 0 1 Prescaled Clock System clock divided by 12 System clock divided by 4 System clock divided by 48 External clock divided by 8 Note: External clock divided by 8 is synchronized with the system clock. Rev. 0.5 249 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.4. TL0: Timer 0 Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x8A Bits 7-0: TL0: Timer 0 Low Byte. The TL0 register is the low byte of the 16-bit Timer 0. SFR Definition 21.5. TL1: Timer 1 Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x8B Bits 7-0: TL1: Timer 1 Low Byte. The TL1 register is the low byte of the 16-bit Timer 1. SFR Definition 21.6. TH0: Timer 0 High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x8C Bits 7-0: TH0: Timer 0 High Byte. The TH0 register is the high byte of the 16-bit Timer 0. SFR Definition 21.7. TH1: Timer 1 High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x8D Bits 7-0: TH1: Timer 1 High Byte. The TH1 register is the high byte of the 16-bit Timer 1. 250 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 21.2. Timer 2 Timer 2 is a 16-bit timer formed by two 8-bit SFRs: TMR2L (low byte) and TMR2H (high byte). Timer 2 may operate in 16-bit auto-reload mode, (split) 8-bit auto-reload mode, USB Start-of-Frame (SOF) capture mode, or Low-Frequency Oscillator (LFO) Falling Edge capture mode. The Timer 2 operation mode is defined by the T2SPLIT (TMR2CN.3), T2CE (TMR2CN.4) bits, and T2CSS (TMR2CN.1) bits. Timer 2 may be clocked by the system clock, the system clock divided by 12, or the external oscillator source divided by 8. The external clock mode is ideal for real-time clock (RTC) functionality, where the internal oscillator drives the system clock while Timer 2 (and/or the PCA) is clocked by an external precision oscillator. Note that the external oscillator source divided by 8 is synchronized with the system clock. 21.2.1. 16-bit Timer with Auto-Reload When T2SPLIT = `0' and T2CE = `0', Timer 2 operates as a 16-bit timer with auto-reload. Timer 2 can be clocked by SYSCLK, SYSCLK divided by 12, or the external oscillator clock source divided by 8. As the 16-bit timer register increments and overflows from 0xFFFF to 0x0000, the 16-bit value in the Timer 2 reload registers (TMR2RLH and TMR2RLL) is loaded into the Timer 2 register as shown in Figure 21.4, and the Timer 2 High Byte Overflow Flag (TMR2CN.7) is set. If Timer 2 interrupts are enabled, an interrupt will be generated on each Timer 2 overflow. Additionally, if Timer 2 interrupts are enabled and the TF2LEN bit is set (TMR2CN.5), an interrupt will be generated each time the lower 8 bits (TMR2L) overflow from 0xFF to 0x00. CKCON T2XCLK TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 To SMBus To ADC, SMBus SYSCLK / 12 0 0 TR2 TCLK TL2 Overflow External Clock / 8 SYSCLK 1 TMR2RLL TMR2RLH Reload Figure 21.4. Timer 2 16-Bit Mode Block Diagram Rev. 0.5 TMR2CN 1 TMR2L TMR2H TF2H TF2L TF2LEN T2CE T2SPLIT TR2 T2CSS T2XCLK Interrupt 251 C8051F340/1/2/3/4/5/6/7 21.2.2. 8-bit Timers with Auto-Reload When T2SPLIT = `1' and T2CE = `0', Timer 2 operates as two 8-bit timers (TMR2H and TMR2L). Both 8-bit timers operate in auto-reload mode as shown in Figure 21.5. TMR2RLL holds the reload value for TMR2L; TMR2RLH holds the reload value for TMR2H. The TR2 bit in TMR2CN handles the run control for TMR2H. TMR2L is always running when configured for 8-bit Mode. Each 8-bit timer may be configured to use SYSCLK, SYSCLK divided by 12, or the external oscillator clock source divided by 8. The Timer 2 Clock Select bits (T2MH and T2ML in CKCON) select either SYSCLK or the clock defined by the Timer 2 External Clock Select bit (T2XCLK in TMR2CN), as follows: T2MH 0 0 1 T2XCLK 0 1 X TMR2H Clock Source SYSCLK / 12 External Clock / 8 SYSCLK T2ML 0 0 1 T2XCLK 0 1 X TMR2L Clock Source SYSCLK / 12 External Clock / 8 SYSCLK The TF2H bit is set when TMR2H overflows from 0xFF to 0x00; the TF2L bit is set when TMR2L overflows from 0xFF to 0x00. When Timer 2 interrupts are enabled, an interrupt is generated each time TMR2H overflows. If Timer 2 interrupts are enabled and TF2LEN (TMR2CN.5) is set, an interrupt is generated each time either TMR2L or TMR2H overflows. When TF2LEN is enabled, software must check the TF2H and TF2L flags to determine the source of the Timer 2 interrupt. The TF2H and TF2L interrupt flags are not cleared by hardware and must be manually cleared by software. CKCON T2XCLK TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 TMR2RLH Reload To SMBus SYSCLK / 12 0 0 External Clock / 8 1 TR2 1 TCLK TMR2H TMR2CN TMR2RLL SYSCLK Reload TF2H TF2L TF2LEN T2CE T2SPLIT TR2 T2CSS T2XCLK Interrupt 1 TCLK 0 TMR2L To ADC, SMBus Figure 21.5. Timer 2 8-Bit Mode Block Diagram 252 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 21.2.3. Timer 2 Capture Modes: USB Start-of-Frame or LFO Falling Edge When T2CE = `1', Timer 2 will operate in one of two special capture modes. The capture event can be selected between a USB Start-of-Frame (SOF) capture, and a Low-Frequency Oscillator (LFO) Falling Edge capture, using the T2CSS bit. The USB SOF capture mode can be used to calibrate the system clock or external oscillator against the known USB host SOF clock. The LFO falling-edge capture mode can be used to calibrate the internal Low-Frequency Oscillator against the internal High-Frequency Oscillator or an external clock source. When T2SPLIT = `0', Timer 2 counts up and overflows from 0xFFFF to 0x0000. Each time a capture event is received, the contents of the Timer 2 registers (TMR2H:TMR2L) are latched into the Timer 2 Reload registers (TMR2RLH:TMR2RLL). A Timer 2 interrupt is generated if enabled. TMR2CN T F 2 H T F 2 L TT F2 2C LE E N TTTT 2R22 S2CX P SC L SL I K T CKCON TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 To SMBus SYSCLK / 12 0 0 TR2 TCLK TL2 Overflow External Clock / 8 SYSCLK 1 1 TMR2L TMR2H To ADC, SMBus USB Start-of-Frame (SOF) 0 Capture TMR2RLL TMR2RLH Low-Frequency Oscillator Falling Edge 1 T2CSS Enable Interrupt Figure 21.6. Timer 2 Capture Mode (T2SPLIT = `0') Rev. 0.5 253 C8051F340/1/2/3/4/5/6/7 When T2SPLIT = `1', the Timer 2 registers (TMR2H and TMR2L) act as two 8-bit counters. Each counter counts up independently and overflows from 0xFF to 0x00. Each time a capture event is received, the contents of the Timer 2 registers are latched into the Timer 2 Reload registers (TMR2RLH and TMR2RLL). A Timer 2 interrupt is generated if enabled. TMR2CN T F 2 H T F 2 L TT F2 2C LE E N TTTT 2R22 S2CX P SC L SL I K T CKCON TTTTTTSS 3 3 2 2 1 0CC MMMMMM A A HLHL 10 TMR2RLH Capture Enable Interrupt SYSCLK / 12 0 0 External Clock / 8 1 TR2 1 TCLK TMR2H To SMBus TMR2RLL SYSCLK Capture 1 TCLK 0 USB Start-of-Frame (SOF) 0 TMR2L To ADC, SMBus Low-Frequency Oscillator Falling Edge 1 T2CSS Figure 21.7. Timer 2 Capture Mode (T2SPLIT = `1') 254 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.8. TMR2CN: Timer 2 Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value TF2H Bit7 TF2L Bit6 TF2LEN Bit5 T2CE Bit4 T2SPLIT Bit3 TR2 Bit2 T2CSS Bit1 T2XCLK Bit0 00000000 SFR Address: (bit addressable) 0xC8 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: TF2H: Timer 2 High Byte Overflow Flag. Set by hardware when the Timer 2 high byte overflows from 0xFF to 0x00. In 16 bit mode, this will occur when Timer 2 overflows from 0xFFFF to 0x0000. When the Timer 2 interrupt is enabled, setting this bit causes the CPU to vector to the Timer 2 interrupt service routine. TF2H is not automatically cleared by hardware and must be cleared by software. TF2L: Timer 2 Low Byte Overflow Flag. Set by hardware when the Timer 2 low byte overflows from 0xFF to 0x00. When this bit is set, an interrupt will be generated if TF2LEN is set and Timer 2 interrupts are enabled. TF2L will set when the low byte overflows regardless of the Timer 2 mode. This bit is not automatically cleared by hardware. TF2LEN: Timer 2 Low Byte Interrupt Enable. This bit enables/disables Timer 2 Low Byte interrupts. If TF2LEN is set and Timer 2 interrupts are enabled, an interrupt will be generated when the low byte of Timer 2 overflows. 0: Timer 2 Low Byte interrupts disabled. 1: Timer 2 Low Byte interrupts enabled. T2CE: Timer 2 Capture Enable 0: Capture function disabled. 1: Capture function enabled. The timer is in capture mode, with the capture event selected by bit T2CSS. Each time a capture event is received, the contents of the Timer 2 registers (TMR2H and TMR2L) are latched into the Timer 2 reload registers (TMR2RLH and TMR2RLH), and a Timer 2 interrupt is generated (if enabled). T2SPLIT: Timer 2 Split Mode Enable. When this bit is set, Timer 2 operates as two 8-bit timers with auto-reload. 0: Timer 2 operates in 16-bit auto-reload mode. 1: Timer 2 operates as two 8-bit auto-reload timers. TR2: Timer 2 Run Control. This bit enables/disables Timer 2. In 8-bit mode, this bit enables/disables TMR2H only; TMR2L is always enabled in this mode. 0: Timer 2 disabled. 1: Timer 2 enabled. T2CSS: Timer 2 Capture Source Select. This bit selects the source of a capture event when bit T2CE is set to `1'. 0: Capture source is USB SOF event. 1: Capture source is falling edge of Low-Frequency Oscillator. T2XCLK: Timer 2 External Clock Select. This bit selects the external clock source for Timer 2. If Timer 2 is in 8-bit mode, this bit selects the external oscillator clock source for both timer bytes. However, the Timer 2 Clock Select bits (T2MH and T2ML in register CKCON) may still be used to select between the external clock and the system clock for either timer. 0: Timer 2 external clock selection is the system clock divided by 12. 1: Timer 2 external clock selection is the external clock divided by 8. Note that the external oscillator source divided by 8 is synchronized with the system clock. Rev. 0.5 255 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.9. TMR2RLL: Timer 2 Reload Register Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xCA Bits 7-0: TMR2RLL: Timer 2 Reload Register Low Byte. TMR2RLL holds the low byte of the reload value for Timer 2 when operating in auto-reload mode, or the captured value of the TMR2L register in capture mode. SFR Definition 21.10. TMR2RLH: Timer 2 Reload Register High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xCB Bits 7-0: TMR2RLH: Timer 2 Reload Register High Byte. The TMR2RLH holds the high byte of the reload value for Timer 2 when operating in auto-reload mode, or the captured value of the TMR2H register in capture mode. SFR Definition 21.11. TMR2L: Timer 2 Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xCC Bits 7-0: TMR2L: Timer 2 Low Byte. In 16-bit mode, the TMR2L register contains the low byte of the 16-bit Timer 2. In 8-bit mode, TMR2L contains the 8-bit low byte timer value. SFR Definition 21.12. TMR2H Timer 2 High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xCD Bits 7-0: TMR2H: Timer 2 High Byte. In 16-bit mode, the TMR2H register contains the high byte of the 16-bit Timer 2. In 8-bit mode, TMR2H contains the 8-bit high byte timer value. 256 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 21.3. Timer 3 Timer 3 is a 16-bit timer formed by two 8-bit SFRs: TMR3L (low byte) and TMR3H (high byte). Timer 3 may operate in 16-bit auto-reload mode, (split) 8-bit auto-reload mode, USB Start-of-Frame (SOF) capture mode, or Low-Frequency Oscillator (LFO) Rising Edge capture mode. The Timer 3 operation mode is defined by the T3SPLIT (TMR3CN.3), T3CE (TMR3CN.4) bits, and T3CSS (TMR3CN.1) bits. Timer 3 may be clocked by the system clock, the system clock divided by 12, or the external oscillator source divided by 8. The external clock mode is ideal for real-time clock (RTC) functionality, where the internal oscillator drives the system clock while Timer 3 (and/or the PCA) is clocked by an external precision oscillator. Note that the external oscillator source divided by 8 is synchronized with the system clock. 21.3.1. 16-bit Timer with Auto-Reload When T3SPLIT (TMR3CN.3) is `0' and T3CE = `0', Timer 3 operates as a 16-bit timer with auto-reload. Timer 3 can be clocked by SYSCLK, SYSCLK divided by 12, or the external oscillator clock source divided by 8. As the 16-bit timer register increments and overflows from 0xFFFF to 0x0000, the 16-bit value in the Timer 3 reload registers (TMR3RLH and TM3RLL) is loaded into the Timer 3 register as shown in Figure 21.4, and the Timer 3 High Byte Overflow Flag (TMR3CN.7) is set. If Timer 3 interrupts are enabled, an interrupt will be generated on each Timer 3 overflow. Additionally, if Timer 3 interrupts are enabled and the TF3LEN bit is set (TMR3CN.5), an interrupt will be generated each time the lower 8 bits (TMR3L) overflow from 0xFF to 0x00. CKCON T3XCLK TTTTTTSS 3 3 2 2 1 0CC MMMMMM A A HLHL 10 To ADC SYSCLK / 12 0 0 TR3 TCLK External Clock / 8 SYSCLK 1 TMR3RLL TMR3RLH Reload Figure 21.8. Timer 3 16-Bit Mode Block Diagram Rev. 0.5 TMR3CN 1 TMR3L TMR3H TF3H TF3L TF3LEN T3CE T3SPLIT TR3 T3CSS T3XCLK Interrupt 257 C8051F340/1/2/3/4/5/6/7 21.3.2. 8-bit Timers with Auto-Reload When T3SPLIT is `1' and T3CE = `0', Timer 3 operates as two 8-bit timers (TMR3H and TMR3L). Both 8-bit timers operate in auto-reload mode as shown in Figure 21.5. TMR3RLL holds the reload value for TMR3L; TMR3RLH holds the reload value for TMR3H. The TR3 bit in TMR3CN handles the run control for TMR3H. TMR3L is always running when configured for 8-bit Mode. Each 8-bit timer may be configured to use SYSCLK, SYSCLK divided by 12, or the external oscillator clock source divided by 8. The Timer 3 Clock Select bits (T3MH and T3ML in CKCON) select either SYSCLK or the clock defined by the Timer 3 External Clock Select bit (T3XCLK in TMR3CN), as follows: T3MH 0 0 1 T3XCLK 0 1 X TMR3H Clock Source SYSCLK / 12 External Clock / 8 SYSCLK T3ML 0 0 1 T3XCLK 0 1 X TMR3L Clock Source SYSCLK / 12 External Clock / 8 SYSCLK The TF3H bit is set when TMR3H overflows from 0xFF to 0x00; the TF3L bit is set when TMR3L overflows from 0xFF to 0x00. When Timer 3 interrupts are enabled, an interrupt is generated each time TMR3H overflows. If Timer 3 interrupts are enabled and TF3LEN (TMR3CN.5) is set, an interrupt is generated each time either TMR3L or TMR3H overflows. When TF3LEN is enabled, software must check the TF3H and TF3L flags to determine the source of the Timer 3 interrupt. The TF3H and TF3L interrupt flags are not cleared by hardware and must be manually cleared by software. CKCON T3XCLK TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 TMR3RLH Reload To ADC SYSCLK / 12 0 0 External Clock / 8 1 TR3 1 TCLK TMR3H TMR3CN TMR3RLL SYSCLK Reload TF3H TF3L TF3LEN T3CE T3SPLIT TR3 T3CSS T3XCLK Interrupt 1 TCLK 0 TMR3L Figure 21.9. Timer 3 8-Bit Mode Block Diagram 258 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 21.3.3. USB Start-of-Frame Capture When T3CE = `1', Timer 3 will operate in one of two special capture modes. The capture event can be selected between a USB Start-of-Frame (SOF) capture, and a Low-Frequency Oscillator (LFO) Rising Edge capture, using the T3CSS bit. The USB SOF capture mode can be used to calibrate the system clock or external oscillator against the known USB host SOF clock. The LFO rising-edge capture mode can be used to calibrate the internal Low-Frequency Oscillator against the internal High-Frequency Oscillator or an external clock source. When T3SPLIT = `0', Timer 3 counts up and overflows from 0xFFFF to 0x0000. Each time a capture event is received, the contents of the Timer 3 registers (TMR3H:TMR3L) are latched into the Timer 3 Reload registers (TMR3RLH:TMR3RLL). A Timer 3 interrupt is generated if enabled. TMR3CN T F 3 H T F 3 L TT F3 3C LE E N TTTT 3R33 S 3CX P SC L SL I K T CKCON TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 SYSCLK / 12 0 0 TR3 TCLK External Clock / 8 SYSCLK 1 1 TMR3L TMR3H To ADC USB Start-of-Frame (SOF) 0 Capture TMR3RLL TMR3RLH Low-Frequency Oscillator Falling Edge 1 T3CSS Enable Interrupt Figure 21.10. Timer 3 Capture Mode (T3SPLIT = `0') Rev. 0.5 259 C8051F340/1/2/3/4/5/6/7 When T3SPLIT = `1', the Timer 3 registers (TMR3H and TMR3L) act as two 8-bit counters. Each counter counts up independently and overflows from 0xFF to 0x00. Each time a capture event is received, the contents of the Timer 3 registers are latched into the Timer 3 Reload registers (TMR3RLH and TMR3RLL). A Timer 3 interrupt is generated if enabled. TMR3CN T F 3 H T F 3 L TT F3 3C LE E N TTTT 3R33 S 3CX P SC L SL I K T CKCON TTTTTTSS 3 3 2 2 1 0CC MMMMMM A A HLHL 10 TMR3RLH Capture Enable Interrupt SYSCLK / 12 0 0 External Clock / 8 1 TR3 1 TCLK TMR3H To ADC TMR3RLL SYSCLK Capture 1 TCLK 0 USB Start-of-Frame (SOF) 0 TMR3L Low-Frequency Oscillator Falling Edge 1 T3CSS Figure 21.11. Timer 3 Capture Mode (T3SPLIT = `1') 260 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.13. TMR3CN: Timer 3 Control R/W R/W R/W R/W R/W R/W R/W R/W Bit0 Reset Value SFR Address: TF3H Bit7 TF3L Bit6 TF3LEN Bit5 T3CE Bit4 T3SPLIT Bit3 TR3 Bit2 T3CSS Bit1 T3XCLK 00000000 0x91 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: TF3H: Timer 3 High Byte Overflow Flag. Set by hardware when the Timer 3 high byte overflows from 0xFF to 0x00. In 16 bit mode, this will occur when Timer 3 overflows from 0xFFFF to 0x0000. When the Timer 3 interrupt is enabled, setting this bit causes the CPU to vector to the Timer 3 interrupt service routine. TF3H is not automatically cleared by hardware and must be cleared by software. TF3L: Timer 3 Low Byte Overflow Flag. Set by hardware when the Timer 3 low byte overflows from 0xFF to 0x00. When this bit is set, an interrupt will be generated if TF3LEN is set and Timer 3 interrupts are enabled. TF3L will set when the low byte overflows regardless of the Timer 3 mode. This bit is not automatically cleared by hardware. TF3LEN: Timer 3 Low Byte Interrupt Enable. This bit enables/disables Timer 3 Low Byte interrupts. If TF3LEN is set and Timer 3 interrupts are enabled, an interrupt will be generated when the low byte of Timer 3 overflows. This bit should be cleared when operating Timer 3 in 16-bit mode. 0: Timer 3 Low Byte interrupts disabled. 1: Timer 3 Low Byte interrupts enabled. T3CE: Timer 3 Capture Enable 0: Capture function disabled. 1: Capture function enabled. The timer is in capture mode, with the capture event selected by bit T3CSS. Each time a capture event is received, the contents of the Timer 3 registers (TMR3H and TMR3L) are latched into the Timer 3 reload registers (TMR3RLH and TMR3RLH), and a Timer 3 interrupt is generated (if enabled). T3SPLIT: Timer 3 Split Mode Enable. When this bit is set, Timer 3 operates as two 8-bit timers with auto-reload. 0: Timer 3 operates in 16-bit auto-reload mode. 1: Timer 3 operates as two 8-bit auto-reload timers. TR3: Timer 3 Run Control. This bit enables/disables Timer 3. In 8-bit mode, this bit enables/disables TMR3H only; TMR3L is always enabled in this mode. 0: Timer 3 disabled. 1: Timer 3 enabled. T3CSS: Timer 3 Capture Source Select. This bit selects the source of a capture event when bit T3CE is set to `1'. 0: Capture source is USB SOF event. 1: Capture source is rising edge of Low-Frequency Oscillator. T3XCLK: Timer 3 External Clock Select. This bit selects the external clock source for Timer 3. If Timer 3 is in 8-bit mode, this bit selects the external oscillator clock source for both timer bytes. However, the Timer 3 Clock Select bits (T3MH and T3ML in register CKCON) may still be used to select between the external clock and the system clock for either timer. 0: Timer 3 external clock selection is the system clock divided by 12. 1: Timer 3 external clock selection is the external clock divided by 8. Note that the external oscillator source divided by 8 is synchronized with the system clock. Rev. 0.5 261 C8051F340/1/2/3/4/5/6/7 SFR Definition 21.14. TMR3RLL: Timer 3 Reload Register Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x92 Bits 7-0: TMR3RLL: Timer 3 Reload Register Low Byte. TMR3RLL holds the low byte of the reload value for Timer 3 when operating in auto-reload mode, or the captured value of the TMR3L register when operating in capture mode. SFR Definition 21.15. TMR3RLH: Timer 3 Reload Register High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x93 Bits 7-0: TMR3RLH: Timer 3 Reload Register High Byte. The TMR3RLH holds the high byte of the reload value for Timer 3 when operating in auto-reload mode, or the captured value of the TMR3H register when operating in capture mode. SFR Definition 21.16. TMR3L: Timer 3 Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x94 Bits 7-0: TMR3L: Timer 3 Low Byte. In 16-bit mode, the TMR3L register contains the low byte of the 16-bit Timer 3. In 8-bit mode, TMR3L contains the 8-bit low byte timer value. SFR Definition 21.17. TMR3H Timer 3 High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0x95 Bits 7-0: TMR3H: Timer 3 High Byte. In 16-bit mode, the TMR3H register contains the high byte of the 16-bit Timer 3. In 8-bit mode, TMR3H contains the 8-bit high byte timer value. 262 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 22. Programmable Counter Array (PCA0) The Programmable Counter Array (PCA0) provides enhanced timer functionality while requiring less CPU intervention than the standard 8051 counter/timers. The PCA consists of a dedicated 16-bit counter/timer and five 16-bit capture/compare modules. Each capture/compare module has its own associated I/O line (CEXn) which is routed through the Crossbar to Port I/O when enabled (See Section "15.1. Priority Crossbar Decoder" on page 149 for details on configuring the Crossbar). The counter/timer is driven by a programmable timebase that can select between six sources: system clock, system clock divided by four, system clock divided by twelve, the external oscillator clock source divided by 8, Timer 0 overflow, or an external clock signal on the ECI input pin. Each capture/compare module may be configured to operate independently in one of six modes: Edge-Triggered Capture, Software Timer, High-Speed Output, Frequency Output, 8-Bit PWM, or 16-Bit PWM (each mode is described in Section "22.2. Capture/Compare Modules" on page 265). The external oscillator clock option is ideal for real-time clock (RTC) functionality, allowing the PCA to be clocked by a precision external oscillator while the internal oscillator drives the system clock. The PCA is configured and controlled through the system controller's Special Function Registers. The PCA block diagram is shown in Figure 22.1 Important Note: The PCA Module 4 may be used as a watchdog timer (WDT), and is enabled in this mode following a system reset. Access to certain PCA registers is restricted while WDT mode is enabled. See Section 22.3 for details. SYSCLK/12 SYSCLK/4 Timer 0 Overflow ECI SYSCLK External Clock/8 PCA CLOCK MUX 16-Bit Counter/Timer Capture/Compare Module 0 Capture/Compare Module 1 Capture/Compare Module 2 Capture/Compare Module 3 Capture/Compare Module 4 / WDT CEX0 CEX1 CEX2 CEX3 CEX4 ECI Crossbar Port I/O Figure 22.1. PCA Block Diagram Rev. 0.5 263 C8051F340/1/2/3/4/5/6/7 22.1. PCA Counter/Timer The 16-bit PCA counter/timer consists of two 8-bit SFRs: PCA0L and PCA0H. PCA0H is the high byte (MSB) of the 16-bit counter/timer and PCA0L is the low byte (LSB). Reading PCA0L automatically latches the value of PCA0H into a "snapshot" register; the following PCA0H read accesses this "snapshot" register. Reading the PCA0L Register first guarantees an accurate reading of the entire 16-bit PCA0 counter. Reading PCA0H or PCA0L does not disturb the counter operation. The CPS2-CPS0 bits in the PCA0MD register select the timebase for the counter/timer as shown in Table 22.1. When the counter/timer overflows from 0xFFFF to 0x0000, the Counter Overflow Flag (CF) in PCA0MD is set to logic 1 and an interrupt request is generated if CF interrupts are enabled. Setting the ECF bit in PCA0MD to logic 1 enables the CF flag to generate an interrupt request. The CF bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by software (Note: PCA0 interrupts must be globally enabled before CF interrupts are recognized. PCA0 interrupts are globally enabled by setting the EA bit (IE.7) and the EPCA0 bit in EIE1 to logic 1). Clearing the CIDL bit in the PCA0MD register allows the PCA to continue normal operation while the CPU is in Idle mode. Table 22.1. PCA Timebase Input Options CPS2 0 0 0 0 1 1 CPS1 0 0 1 1 0 0 CPS0 0 1 0 1 0 1 Timebase System clock divided by 12 System clock divided by 4 Timer 0 overflow High-to-low transitions on ECI (max rate = system clock divided by 4) System clock External oscillator source divided by 8* *Note: External oscillator source divided by 8 is synchronized with the system clock. IDLE PCA0MD CWW I DD DT L LEC K C P S 2 C P S 1 CE PC SF 0 PCA0CN CC FR C C F 4 C C F 3 C C F 2 C C F 1 C C F 0 PCA0L read To SFR Bus Snapshot Register SYSCLK/12 SYSCLK/4 Timer 0 Overflow ECI SYSCLK External Clock/8 000 001 010 011 100 101 0 1 PCA0H PCA0L Overflow CF To PCA Modules To PCA Interrupt System Figure 22.2. PCA Counter/Timer Block Diagram 264 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 22.2. Capture/Compare Modules Each module can be configured to operate independently in one of six operation modes: Edge-triggered Capture, Software Timer, High Speed Output, Frequency Output, 8-Bit Pulse Width Modulator, or 16-Bit Pulse Width Modulator. Each module has Special Function Registers (SFRs) associated with it in the CIP-51 system controller. These registers are used to exchange data with a module and configure the module's mode of operation. Table 22.2 summarizes the bit settings in the PCA0CPMn registers used to select the PCA capture/compare module's operating modes. Setting the ECCFn bit in a PCA0CPMn register enables the module's CCFn interrupt. Note: PCA0 interrupts must be globally enabled before individual CCFn interrupts are recognized. PCA0 interrupts are globally enabled by setting the EA bit and the EPCA0 bit to logic 1. See Figure 22.3 for details on the PCA interrupt configuration. Table 22.2. PCA0CPM Register Settings for PCA Capture/Compare Modules PWM16 ECOM CAPP CAPN MAT X X X X X X 0 1 X X 1 0 0 1 1 0 0 0 0 0 0 0 0 1 1 X X X TOG 0 0 0 0 1 1 0 0 PWM ECCF 0 0 0 0 0 1 1 1 X X X X X X X X X 1 1 0 1 0 1 0 1 0 1 0 X = Don't Care (for n = 0 to 4) Operation Mode Capture triggered by positive edge on CEXn Capture triggered by negative edge on CEXn Capture triggered by transition on CEXn Software Timer High Speed Output Frequency Output 8-Bit Pulse Width Modulator 16-Bit Pulse Width Modulator PCA0CPMn P ECCMT P E WCA A AOWC MOP P TGMC 1 MP N n n n F 6nnn n n PCA Counter/ Timer Overflow PCA0CN CC FR CCCCC CCCCC FFFFF 43210 PCA0MD C WW I DD DTL L EC K CCCE PPPC SSSF 210 0 1 ECCF0 PCA Module 0 (CCF0) ECCF1 0 1 EPCA0 0 1 EA 0 1 Interrupt Priority Decoder PCA Module 1 (CCF1) ECCF2 0 1 PCA Module 2 (CCF2) ECCF3 0 1 PCA Module 3 (CCF3) ECCF4 0 1 PCA Module 4 (CCF4) 0 1 Figure 22.3. PCA Interrupt Block Diagram Rev. 0.5 265 C8051F340/1/2/3/4/5/6/7 22.2.1. Edge-triggered Capture Mode In this mode, a valid transition on the CEXn pin causes the PCA to capture the value of the PCA counter/ timer and load it into the corresponding module's 16-bit capture/compare register (PCA0CPLn and PCA0CPHn). The CAPPn and CAPNn bits in the PCA0CPMn register are used to select the type of transition that triggers the capture: low-to-high transition (positive edge), high-to-low transition (negative edge), or either transition (positive or negative edge). When a capture occurs, the Capture/Compare Flag (CCFn) in PCA0CN is set to logic 1 and an interrupt request is generated if CCF interrupts are enabled. The CCFn bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by software. If both CAPPn and CAPNn bits are set to logic 1, then the state of the Port pin associated with CEXn can be read directly to determine whether a rising-edge or falling-edge caused the capture. PCA Interrupt PCA0CPMn P E CCMT P E WC A A AOWC MOPP TGMC 1 MPN n n n F 6nnn n n x0 000x PCA0CN CC FR CCCCC CCCCC FFFFF 43210 (to CCFn) PCA0CPLn PCA0CPHn 0 Port I/O Crossbar CEXn 1 0 1 PCA Timebase Capture PCA0L PCA0H Figure 22.4. PCA Capture Mode Diagram Note: The CEXn input signal must remain high or low for at least 2 system clock cycles to be recognized by the hardware. 266 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 22.2.2. Software Timer (Compare) Mode In Software Timer mode, the PCA counter/timer value is compared to the module's 16-bit capture/compare register (PCA0CPHn and PCA0CPLn). When a match occurs, the Capture/Compare Flag (CCFn) in PCA0CN is set to logic 1 and an interrupt request is generated if CCF interrupts are enabled. The CCFn bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by software. Setting the ECOMn and MATn bits in the PCA0CPMn register enables Software Timer mode. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/ Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to `0'; writing to PCA0CPHn sets ECOMn to `1'. Write to PCA0CPLn Reset Write to PCA0CPHn 0 ENB ENB PCA Interrupt 1 PCA0CPMn P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6nnn n n x 00 00x Enable Match 0 1 PCA0CN PCA0CPLn PCA0CPHn CC FR CCCCC CCCCC FFFFF 43210 16-bit Comparator PCA Timebase PCA0L PCA0H Figure 22.5. PCA Software Timer Mode Diagram Rev. 0.5 267 C8051F340/1/2/3/4/5/6/7 22.2.3. High Speed Output Mode In High Speed Output mode, a module's associated CEXn pin is toggled each time a match occurs between the PCA Counter and the module's 16-bit capture/compare register (PCA0CPHn and PCA0CPLn) Setting the TOGn, MATn, and ECOMn bits in the PCA0CPMn register enables the High-Speed Output mode. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/ Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to `0'; writing to PCA0CPHn sets ECOMn to `1'. Write to PCA0CPLn Reset Write to PCA0CPHn 0 ENB PCA0CPMn ENB 1 P ECCMT P E WC A A A OWC MOPP TGMC 1 MP N n n n F 6nnn n n x 00 0x PCA Interrupt PCA0CN PCA0CPLn PCA0CPHn CC FR CCCCC CCCCC FFFFF 43210 Enable 16-bit Comparator Match 0 1 TOGn Toggle 0 CEXn 1 Crossbar Port I/O PCA Timebase PCA0L PCA0H Figure 22.6. PCA High Speed Output Mode Diagram 268 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 22.2.4. Frequency Output Mode Frequency Output Mode produces a programmable-frequency square wave on the module's associated CEXn pin. The capture/compare module high byte holds the number of PCA clocks to count before the output is toggled. The frequency of the square wave is then defined by Equation 22.1. F PCA F CEXn = ---------------------------------------2 x PCA0CPHn Note: A value of 0x00 in the PCA0CPHn register is equal to 256 for this equation. Equation 22.1. Square Wave Frequency Output Where FPCA is the frequency of the clock selected by the CPS2-0 bits in the PCA mode register, PCA0MD. The lower byte of the capture/compare module is compared to the PCA counter low byte; on a match, CEXn is toggled and the offset held in the high byte is added to the matched value in PCA0CPLn. Frequency Output Mode is enabled by setting the ECOMn, TOGn, and PWMn bits in the PCA0CPMn register. Write to PCA0CPLn Reset Write to PCA0CPHn 0 ENB PCA0CPMn ENB 1 P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6nnn n n x 000 x Enable PCA0CPLn 8-bit Adder Adder Enable PCA0CPHn TOGn Toggle 8-bit Comparator match 0 CEXn 1 Crossbar Port I/O PCA Timebase PCA0L Figure 22.7. PCA Frequency Output Mode Rev. 0.5 269 C8051F340/1/2/3/4/5/6/7 22.2.5. 8-Bit Pulse Width Modulator Mode Each module can be used independently to generate a pulse width modulated (PWM) output on its associated CEXn pin. The frequency of the output is dependent on the timebase for the PCA counter/timer. The duty cycle of the PWM output signal is varied using the module's PCA0CPLn capture/compare register. When the value in the low byte of the PCA counter/timer (PCA0L) is equal to the value in PCA0CPLn, the output on the CEXn pin will be set. When the count value in PCA0L overflows, the CEXn output will be reset (see Figure 22.8). Also, when the counter/timer low byte (PCA0L) overflows from 0xFF to 0x00, PCA0CPLn is reloaded automatically with the value stored in the module's capture/compare high byte (PCA0CPHn) without software intervention. Setting the ECOMn and PWMn bits in the PCA0CPMn register enables 8-Bit Pulse Width Modulator mode. The duty cycle for 8-Bit PWM Mode is given by Equation 22.2. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/ Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to `0'; writing to PCA0CPHn sets ECOMn to `1'. ( 256 - PCA0CPHn ) DutyCycle = -------------------------------------------------256 Equation 22.2. 8-Bit PWM Duty Cycle Using Equation 22.2, the largest duty cycle is 100% (PCA0CPHn = 0), and the smallest duty cycle is 0.39% (PCA0CPHn = 0xFF). A 0% duty cycle may be generated by clearing the ECOMn bit to `0'. Write to PCA0CPLn Reset Write to PCA0CPHn 0 ENB PCA0CPHn ENB 1 PCA0CPMn P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F n 6nnn n 0 00x0 x Enable PCA0CPLn 8-bit Comparator match S SET Q CEXn Crossbar Port I/O R PCA Timebase CLR Q PCA0L Overflow Figure 22.8. PCA 8-Bit PWM Mode Diagram 270 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 22.2.6. 16-Bit Pulse Width Modulator Mode A PCA module may also be operated in 16-Bit PWM mode. In this mode, the 16-bit capture/compare module defines the number of PCA clocks for the low time of the PWM signal. When the PCA counter matches the module contents, the output on CEXn is asserted high; when the counter overflows, CEXn is asserted low. To output a varying duty cycle, new value writes should be synchronized with PCA CCFn match interrupts. 16-Bit PWM Mode is enabled by setting the ECOMn, PWMn, and PWM16n bits in the PCA0CPMn register. For a varying duty cycle, match interrupts should be enabled (ECCFn = 1 AND MATn = 1) to help synchronize the capture/compare register writes. The duty cycle for 16-Bit PWM Mode is given by Equation 22.3. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/ Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to `0'; writing to PCA0CPHn sets ECOMn to `1'. ( 65536 - PCA0CPn ) DutyCycle = ---------------------------------------------------65536 Equation 22.3. 16-Bit PWM Duty Cycle Using Equation 22.3, the largest duty cycle is 100% (PCA0CPn = 0), and the smallest duty cycle is 0.0015% (PCA0CPn = 0xFFFF). A 0% duty cycle may be generated by clearing the ECOMn bit to `0'. Write to PCA0CPLn Reset Write to PCA0CPHn 0 ENB ENB 1 PCA0CPMn P ECCMT P E WC A A A OWC MOPP TGMC 1 MP N n n n F 6nnn n n 1 00x0 x Enable PCA0CPHn PCA0CPLn 16-bit Comparator match S SET Q CEXn Crossbar Port I/O R PCA Timebase CLR Q PCA0H PCA0L Overflow Figure 22.9. PCA 16-Bit PWM Mode Rev. 0.5 271 C8051F340/1/2/3/4/5/6/7 22.3. Watchdog Timer Mode A programmable watchdog timer (WDT) function is available through the PCA Module 4. The WDT is used to generate a reset if the time between writes to the WDT update register (PCA0CPH4) exceed a specified limit. The WDT can be configured and enabled/disabled as needed by software. With the WDTE and/or WDLCK bits set to `1' in the PCA0MD register, Module 4 operates as a watchdog timer (WDT). The Module 4 high byte is compared to the PCA counter high byte; the Module 4 low byte holds the offset to be used when WDT updates are performed. The Watchdog Timer is enabled on reset. Writes to some PCA registers are restricted while the Watchdog Timer is enabled. 22.3.1. Watchdog Timer Operation While the WDT is enabled: * * * * * * PCA counter is forced on. Writes to PCA0L and PCA0H are not allowed. PCA clock source bits (CPS2-CPS0) are frozen. PCA Idle control bit (CIDL) is frozen. Module 4 is forced into Watchdog Timer mode. Writes to the Module 4 mode register (PCA0CPM4) are disabled. While the WDT is enabled, writes to the CR bit will not change the PCA counter state; the counter will run until the WDT is disabled. The PCA counter run control (CR) will read zero if the WDT is enabled but user software has not enabled the PCA counter. If a match occurs between PCA0CPH4 and PCA0H while the WDT is enabled, a reset will be generated. To prevent a WDT reset, the WDT may be updated with a write of any value to PCA0CPH4. Upon a PCA0CPH4 write, PCA0H plus the offset held in PCA0CPL4 is loaded into PCA0CPH4 (See Figure 22.10). PCA0MD CWW I DD DT L LEC K CCCE PPPC SSSF 210 PCA0CPH4 Enable 8-bit Comparator Match Reset PCA0CPL4 8-bit Adder Adder Enable PCA0H PCA0L Overflow Write to PCA0CPH4 Figure 22.10. PCA Module 4 with Watchdog Timer Enabled Note that the 8-bit offset held in PCA0CPH4 is compared to the upper byte of the 16-bit PCA counter. This offset value is the number of PCA0L overflows before a reset. Up to 256 PCA clocks may pass before the first PCA0L overflow occurs, depending on the value of the PCA0L when the update is performed. The total offset is then given (in PCA clocks) by Equation 22.4, where PCA0L is the value of the PCA0L register at the time of the update. 272 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 Offset = ( 256 x PCA0CPL4 ) + ( 256 - PCA0L ) Equation 22.4. Watchdog Timer Offset in PCA Clocks The WDT reset is generated when PCA0L overflows while there is a match between PCA0CPH4 and PCA0H. Software may force a WDT reset by writing a `1' to the CCF4 flag (PCA0CN.4) while the WDT is enabled. 22.3.2. Watchdog Timer Usage To configure the WDT, perform the following tasks: 1. Disable the WDT by writing a `0' to the WDTE bit. 2. Select the desired PCA clock source (with the CPS2-CPS0 bits). 3. Load PCA0CPL4 with the desired WDT update offset value. 4. Configure the PCA Idle mode (set CIDL if the WDT should be suspended while the CPU is in Idle mode). 5. Enable the WDT by setting the WDTE bit to `1'. 6. (optional) Lock the WDT (prevent WDT disable until the next system reset) by setting the WDLCK bit to `1'. The PCA clock source and Idle mode select cannot be changed while the WDT is enabled. The watchdog timer is enabled by setting the WDTE or WDLCK bits in the PCA0MD register. When WDLCK is set, the WDT cannot be disabled until the next system reset. If WDLCK is not set, the WDT is disabled by clearing the WDTE bit. The WDT is enabled following any reset. The PCA0 counter clock defaults to the system clock divided by 12, PCA0L defaults to 0x00, and PCA0CPL4 defaults to 0x00. Using Equation 22.4, this results in a WDT timeout interval of 256 PCA clocks. Table 22.3 lists some example timeout intervals for typical system clocks. Table 22.3. Watchdog Timer Timeout Intervals1 System Clock (Hz) 12,000,000 12,000,000 12,000,000 24,000,000 24,000,000 24,000,000 1,500,0002 1,500,0002 1,500,0002 32,768 32,768 32,768 PCA0CPL4 255 128 32 255 128 32 255 128 32 255 128 32 Timeout Interval (ms) 65.5 33.0 8.4 32.8 16.5 4.2 524.3 264.2 67.6 24,000 12,093.75 3,093.75 Notes: 1. Assumes SYSCLK / 12 as the PCA clock source, and a PCA0L value of 0x00 at the update time. 2. System Clock reset frequency. Rev. 0.5 273 C8051F340/1/2/3/4/5/6/7 22.4. Register Descriptions for PCA Following are detailed descriptions of the special function registers related to the operation of the PCA. SFR Definition 22.1. PCA0CN: PCA Control R/W R/W R/W R/W R/W R/W R/W R/W Reset Value CF Bit7 CR Bit6 Bit5 CCF4 Bit4 CCF3 Bit3 CCF2 Bit2 CCF1 Bit1 CCF0 Bit0 (bit addressable) 00000000 SFR Address: 0xD8 Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: CF: PCA Counter/Timer Overflow Flag. Set by hardware when the PCA Counter/Timer overflows from 0xFFFF to 0x0000. When the Counter/Timer Overflow (CF) interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. CR: PCA Counter/Timer Run Control. This bit enables/disables the PCA Counter/Timer. 0: PCA Counter/Timer disabled. 1: PCA Counter/Timer enabled. UNUSED. Read = 0b, Write = don't care. CCF4: PCA Module 4 Capture/Compare Flag. This bit is set by hardware when a match or capture occurs. When the CCF4 interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. CCF3: PCA Module 3 Capture/Compare Flag. This bit is set by hardware when a match or capture occurs. When the CCF3 interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. CCF2: PCA Module 2 Capture/Compare Flag. This bit is set by hardware when a match or capture occurs. When the CCF2 interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. CCF1: PCA Module 1 Capture/Compare Flag. This bit is set by hardware when a match or capture occurs. When the CCF1 interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. CCF0: PCA Module 0 Capture/Compare Flag. This bit is set by hardware when a match or capture occurs. When the CCF0 interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. 274 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 22.2. PCA0MD: PCA Mode R/W R/W R/W R/W R/W R/W R/W R/W Reset Value CIDL Bit7 WDTE Bit6 WDLCK Bit5 Bit4 CPS2 Bit3 CPS1 Bit2 CPS0 Bit1 ECF Bit0 01000000 SFR Address: 0xD9 CIDL: PCA Counter/Timer Idle Control. Specifies PCA behavior when CPU is in Idle Mode. 0: PCA continues to function normally while the system controller is in Idle Mode. 1: PCA operation is suspended while the system controller is in Idle Mode. Bit6: WDTE: Watchdog Timer Enable If this bit is set, PCA Module 4 is used as the watchdog timer. 0: Watchdog Timer disabled. 1: PCA Module 4 enabled as Watchdog Timer. Bit5: WDLCK: Watchdog Timer Lock This bit enables and locks the Watchdog Timer. When WDLCK is set to `1', the Watchdog Timer may not be disabled until the next system reset. 0: Watchdog Timer unlocked. 1: Watchdog Timer enabled and locked. Bit4: UNUSED. Read = 0b, Write = don't care. Bits3-1: CPS2-CPS0: PCA Counter/Timer Pulse Select. These bits select the timebase source for the PCA counter. Bit7: CPS2 0 0 0 0 1 1 1 1 CPS1 0 0 1 1 0 0 1 1 CPS0 0 1 0 1 0 1 0 1 Timebase System clock divided by 12 System clock divided by 4 Timer 0 overflow High-to-low transitions on ECI (max rate = system clock divided by 4) System clock External clock divided by 8* Reserved Reserved *Note: External oscillator source divided by 8 is synchronized with the system clock. Bit0: ECF: PCA Counter/Timer Overflow Interrupt Enable. This bit sets the masking of the PCA Counter/Timer Overflow (CF) interrupt. 0: Disable the CF interrupt. 1: Enable a PCA Counter/Timer Overflow interrupt request when CF (PCA0CN.7) is set. Note: When the WDTE bit is set to `1', the PCA0MD register cannot be modified. To change the contents of the PCA0MD register, the Watchdog Timer must first be disabled. Rev. 0.5 275 C8051F340/1/2/3/4/5/6/7 SFR Definition 22.3. PCA0CPMn: PCA Capture/Compare Mode R/W R/W R/W R/W R/W R/W R/W R/W Reset Value PWM16n Bit7 ECOMn Bit6 CAPPn Bit5 CAPNn Bit4 MATn Bit3 TOGn Bit2 PWMn Bit1 EECFn Bit0 00000000 SFR Address: 0xDA, 0xDB, 0xDC, 0xDD, 0xDE PCA0CPMn Address: Bit7: Bit6: Bit5: Bit4: Bit3: Bit2: Bit1: Bit0: PCA0CPM0 = 0xDA (n = 0), PCA0CPM1 = 0xDB (n = 1), PCA0CPM2 = 0xDC (n = 2), PCA0CPM3 = 0xDD (n = 3), PCA0CPM4 = 0xDE (n = 4) PWM16n: 16-bit Pulse Width Modulation Enable. This bit selects 16-bit mode when Pulse Width Modulation mode is enabled (PWMn = 1). 0: 8-bit PWM selected. 1: 16-bit PWM selected. ECOMn: Comparator Function Enable. This bit enables/disables the comparator function for PCA module n. 0: Disabled. 1: Enabled. CAPPn: Capture Positive Function Enable. This bit enables/disables the positive edge capture for PCA module n. 0: Disabled. 1: Enabled. CAPNn: Capture Negative Function Enable. This bit enables/disables the negative edge capture for PCA module n. 0: Disabled. 1: Enabled. MATn: Match Function Enable. This bit enables/disables the match function for PCA module n. When enabled, matches of the PCA counter with a module's capture/compare register cause the CCFn bit in PCA0MD register to be set to logic 1. 0: Disabled. 1: Enabled. TOGn: Toggle Function Enable. This bit enables/disables the toggle function for PCA module n. When enabled, matches of the PCA counter with a module's capture/compare register cause the logic level on the CEXn pin to toggle. If the PWMn bit is also set to logic 1, the module operates in Frequency Output Mode. 0: Disabled. 1: Enabled. PWMn: Pulse Width Modulation Mode Enable. This bit enables/disables the PWM function for PCA module n. When enabled, a pulse width modulated signal is output on the CEXn pin. 8-bit PWM is used if PWM16n is cleared; 16-bit mode is used if PWM16n is set to logic 1. If the TOGn bit is also set, the module operates in Frequency Output Mode. 0: Disabled. 1: Enabled. ECCFn: Capture/Compare Flag Interrupt Enable. This bit sets the masking of the Capture/Compare Flag (CCFn) interrupt. 0: Disable CCFn interrupts. 1: Enable a Capture/Compare Flag interrupt request when CCFn is set. 276 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 SFR Definition 22.4. PCA0L: PCA Counter/Timer Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xF9 Bits 7-0: PCA0L: PCA Counter/Timer Low Byte. The PCA0L register holds the low byte (LSB) of the 16-bit PCA Counter/Timer. SFR Definition 22.5. PCA0H: PCA Counter/Timer High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xFA Bits 7-0: PCA0H: PCA Counter/Timer High Byte. The PCA0H register holds the high byte (MSB) of the 16-bit PCA Counter/Timer. SFR Definition 22.6. PCA0CPLn: PCA Capture Module Low Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xFB, 0xE9, 0xEB, 0xED, 0xFD PCA0CPLn Address: PCA0CPL0 = 0xFB (n = 0), PCA0CPL1 = 0xE9 (n = 1), PCA0CPL2 = 0xEB (n = 2), PCA0CPL3 = 0xED (n = 3), PCA0CPL4 = 0xFD (n = 4) Bits7-0: PCA0CPLn: PCA Capture Module Low Byte. The PCA0CPLn register holds the low byte (LSB) of the 16-bit capture module n. Rev. 0.5 277 C8051F340/1/2/3/4/5/6/7 SFR Definition 22.7. PCA0CPHn: PCA Capture Module High Byte R/W Bit7 R/W Bit6 R/W Bit5 R/W Bit4 R/W Bit3 R/W Bit2 R/W Bit1 R/W Bit0 Reset Value 00000000 SFR Address: 0xFC, 0xEA, 0xEC,0xEE, 0xFE PCA0CPHn Address: PCA0CPH0 = 0xFC (n = 0), PCA0CPH1 = 0xEA (n = 1), PCA0CPH2 = 0xEC (n = 2), PCA0CPH3 = 0xEE (n = 3), PCA0CPH4 = 0xFE (n = 4) Bits7-0: PCA0CPHn: PCA Capture Module High Byte. The PCA0CPHn register holds the high byte (MSB) of the 16-bit capture module n. 278 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 23. C2 Interface C8051F340/1/2/3/4/5/6/7 devices include an on-chip Silicon Labs 2-Wire (C2) debug interface to allow Flash programming and in-system debugging with the production part installed in the end application. The C2 interface uses a clock signal (C2CK) and a bi-directional C2 data signal (C2D) to transfer information between the device and a host system. See the C2 Interface Specification for details on the C2 protocol. 23.1. C2 Interface Registers The following describes the C2 registers necessary to perform Flash programming functions through the C2 interface. All C2 registers are accessed through the C2 interface as described in the C2 Interface Specification. C2 Register Definition 23.1. C2ADD: C2 Address Reset Value 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Bits7-0: The C2ADD register is accessed via the C2 interface to select the target Data register for C2 Data Read and Data Write commands. Address 0x00 0x01 0x02 0xAD Description Selects the Device ID register for Data Read instructions Selects the Revision ID register for Data Read instructions Selects the C2 Flash Programming Control register for Data Read/Write instructions Selects the C2 Flash Programming Data register for Data Read/Write instructions C2 Register Definition 23.2. DEVICEID: C2 Device ID Reset Value 00001111 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 This read-only register returns the 8-bit device ID: 0x0F (C8051F340/1/2/3/4/5/6/7). Rev. 0.5 279 C8051F340/1/2/3/4/5/6/7 C2 Register Definition 23.3. REVID: C2 Revision ID Reset Value Variable Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 This read-only register returns the 8-bit revision ID. C2 Register Definition 23.4. FPCTL: C2 Flash Programming Control Reset Value 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Bits7-0 FPCTL: Flash Programming Control Register. This register is used to enable Flash programming via the C2 interface. To enable C2 Flash programming, the following codes must be written in order: 0x02, 0x01. Note that once C2 Flash programming is enabled, a system reset must be issued to resume normal operation. C2 Register Definition 23.5. FPDAT: C2 Flash Programming Data Reset Value 00000000 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Bits7-0: FPDAT: C2 Flash Programming Data Register. This register is used to pass Flash commands, addresses, and data during C2 Flash accesses. Valid commands are listed below. Code 0x06 0x07 0x08 0x03 Command Flash Block Read Flash Block Write Flash Page Erase Device Erase 280 Rev. 0.5 C8051F340/1/2/3/4/5/6/7 23.2. C2 Pin Sharing The C2 protocol allows the C2 pins to be shared with user functions so that in-system debugging and Flash programming functions may be performed. This is possible because C2 communication is typically performed when the device is in the halt state, where all on-chip peripherals and user software are stalled. In this halted state, the C2 interface can safely `borrow' the C2CK (/RST) and C2D (P3.0) pins. In most applications, external resistors are required to isolate C2 interface traffic from the user application. A typical isolation configuration is shown in Figure 23.1. C8051Fxxx /Reset (a) Input (b) Output (c) C2CK C2D C2 Interface Master Figure 23.1. Typical C2 Pin Sharing The configuration in Figure 23.1 assumes the following: 1. The user input (b) cannot change state while the target device is halted. 2. The /RST pin on the target device is used as an input only. Additional resistors may be necessary depending on the specific application. Rev. 0.5 281 C8051F340/1/2/3/4/5/6/7 CONTACT INFORMATION Silicon Laboratories Inc. 4635 Boston Lane Austin, TX 78735 Tel: 1+(512) 416-8500 Fax: 1+(512) 416-9669 Toll Free: 1+(877) 444-3032 Email: MCUinfo@silabs.com Internet: www.silabs.com The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice. Silicon Laboratories assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from the use of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed features or parameters. Silicon Laboratories reserves the right to make changes without further notice. Silicon Laboratories makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Silicon Laboratories assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Silicon Laboratories products are not designed, intended, or authorized for use in applications intended to support or sustain life, or for any other application in which the failure of the Silicon Laboratories product could create a situation where personal injury or death may occur. Should Buyer purchase or use Silicon Laboratories products for any such unintended or unauthorized application, Buyer shall indemnify and hold Silicon Laboratories harmless against all claims and damages. Silicon Laboratories and Silicon Labs are trademarks of Silicon Laboratories Inc. Other products or brand names mentioned herein are trademarks or registered trademarks of their respective holders 282 Rev. 0.5 |
Price & Availability of C8051F340
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |