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AN1422 APPLICATION NOTE
Designing with Flash+PSD Memory
CONTENTS (Introduction on next page)
January 2002
1/3
Programmable Peripheral
Application Note 048
Designing with Flash Memory
Introduction
Flash Memory has gained a wide popularity as a choice of use in embedded system solutions. Many designers, who are using Microcontrollers, are using Flash Memory for program store and sometimes also for data store. The ability to reprogram Flash Memory in the system has allowed designers to change the program code in production or out in the field without a large expense of doing so. What many designers are not aware of is the complexity of designing with Flash Memory for In-System Programming (ISP). One important point to remember when reprogramming Flash Memory: the programming algorithm cannot be executed out of the same Flash Memory device that is being programmed. It must be executed out of a separate memory device such as an EPROM or SRAM device. At the time of this publication, there are no cost effective Flash Memory devices that can perform this dual function. This Application Note will address the issues of designing Flash Memory into a system and show an easy solution using ST's PSD device as a Flash Support Chip (FSP). The next few sections discuss the design issues of using Flash Memory. A summary of these issues are shown in Table 1. The two main reasons why designers use Flash Memory is to have the ability to cost effectively change the program code in the field, and to load the latest version of program code into the system just prior to shipping the product. Other designers may also use segmented Flash Memory to store variables or calibration data. Flash Memory is also used in manufacturing for running test programs. This can help decrease the cost of manufacturing a product. The designer must determine the method of programming a Flash Memory the first time and reprogramming the Flash Memory in-system after the first time. The technique of performing these two functions may be very different. The Flash Memory can be initially programmed by an EPROM programmer, or programmed in the system using a Boot EPROM or ROM, or programmed in the system using a Microcontroller with a JTAG Port. If the system boots up out of the boot sector of the Flash Memory, this boot sector must be initially programmed either by an external EPROM programmer prior to the Flash Memory being assembled on the board or by an MCU with a JTAG Port. Since most low cost Microcontrollers do not have a JTAG Port, there is an added cost of programming Flash Memory on an EPROM Programmer prior to being assembled on the board. When reprogramming the Flash Memory in-circuit, a serial port or JTAG port must be used. If a serial port is used, the data is downloaded to SRAM prior to being programmed into the Flash Memory. Next, the Microcontroller must execute the programming algorithms to reprogram the Flash Memory with the data that was downloaded from the serial port. If the system does not have a separate boot EPROM or ROM to execute the programming algorithms, the programming algorithms must be copied from the boot sector of the Flash Memory into the SRAM. The programming algorithms must then be executed from the SRAM while programming the Flash Memory. A common mistake designers make is thinking that they can execute the programming algorithms out of the same Flash Memory they are trying to program.
Reason for Using Flash Memory
Methods of Programming
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Flash Memory - Application Note 048
Methods of Programming
(cont.)
If a JTAG port is available on the MCU, this port can be used to reprogram the Flash Memory in the same manner as programming the Flash Memory the first time. The boot code can be downloaded through the JTAG port into local SRAM inside the Microcontroller while the Microcontroller is being held in reset. The boundary scan registers on the Microcontroller can also be used to program the Flash Memory in-circuit. Since most low cost Microcontrollers do not have a JTAG Port, further discussions in this application note will assume that a JTAG Port is not available. Flash Memory can be programmed in various stages of the manufacturing process. If no boot EPROM or ROM is used in the system, the Flash Memory must be programmed on an EPROM Programmer prior to being assembled onto the board. As a minimum, the boot sector must be programmed at this time. Manufacturing personnel must be careful not to assemble the wrong programmed part on the board. This mistake may be costly as it will be detected in Functional Test where test time and troubleshooting is expensive. The program code may also change prior to shipping the product. If this occurs, programming at this stage will be an unnecessary cost added to manufacturing. During in-circuit test, test code may be loaded into Flash Memory. This may simplify the testability of the system. Functional Test is the most expensive stage for detecting a bad or incorrectly programmed Flash Memory. From a manufacturing point of view, the least expensive Flash solution is having the ability to assemble a blank Flash Memory device on the board and program it during the in-circuit test phase. This requires a separate boot EPROM or ROM. There are various system programming issues that must be considered when designing Flash Memory systems. The most important issue was stated previously: the system cannot execute the programming algorithms from the same Flash Memory being programmed. Some designers will store the programming algorithms in the boot sector of the Flash Memory. When programming the Flash Memory, the system must copy the algorithms from Flash to SRAM. The system will next execute the algorithms from SRAM to program the Flash Memory. Taking a closer look at what is involved in doing this, I will use an 80C31 for an example. The 80C31 has a separate Program Space and Data Space. Initially the Flash Memory is in the Program Space and the SRAM is in the Data Space. To copy the algorithms from Flash Memory to SRAM, the Flash Memory and SRAM must be in the Data Space. The code executing in the Flash Memory to copy the algorithms must be in the Program Space. Once the algorithms are in the SRAM, the SRAM must be moved to the Program Space while the Flash Memory remains in the Data Space. To work around this problem, both the Flash Memory and SRAM must be in both the Program and Data Space at the same time. This can be a problem if the sum of memory sizes of the Flash Memory, SRAM, and other I/O functions exceeds the 64 Kbytes of address space. The solution to this problem requires a lot of PLD logic for address decoding in both the Operational and Programming Modes along with a page register to extend the addressing capabilities of the 80C31 in the Programming Mode. There are other concerns the designer must consider. What if power fails while the Microcontroller is executing the programming algorithm from SRAM? The programming state machine built into Flash Memories must reset itself and allow access to the boot sector when powering the system back up. The system then must have the ability to reprogram the corrupted Flash Memory. The boot block in the system must be write protected. If this boot block is corrupted for any reason, the system will be inoperative. The best protection for the boot block and programming algorithms is to store them in EPROM or ROM technology. If there is a way to reprogram the boot block, there is a way to corrupt it. Some sector protect techniques cannot guarantee that the sector will not be corrupted when the Microcontroller malfunctions and executes the wrong code (maybe unlocking and corrupting a sector).
Manufacturing Stages of Programming
System Programming Issues
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Flash Memory - Application Note 048
System Programming Issues (cont.)
Table 1. Pr ogramming Flash Memory Using SRAM for Executing Programming Algorithms
Need to program Flash Memory the first time on a PROM Programmer.
Using the PSDXXX for Executing Programming Algorithms and Integrating Other Support Logic
Program one PSD device vs. programming Flash Memory and PLDs on PROM Programmer. Blank Flash Memory can be assembled on board. Execute programming algorithm from PSD's internal EPROM. There is no requirement to down load the programming algorithm to SRAM
Requires MCU to down load the programming algorithms from Flash Memory to SRAM and execute from SRAM to program the Flash Memory. The MCU must execute code from a memory device while down loading the programming algorithms to SRAM Must re-map the SRAM from Data Space to Code Space to execute the Programming Algorithms. May require additional PLD Logic (when using an 80C31). Need PLD Logic for changing the memory map to access Flash Memory in both Program and Data Space (when using an 80C31). Need PLD Logic for Address Decoding. Need PLD Logic for Paging (if exceeding addressing capability of MCU). Need Address Latch (for multiplexed MCUs). Boot block in Flash Memory is at risk of being corrupted. Longer development time. More complex design for defining Address Map and PLD PLD Logic functions to handle both Flash Memory and SRAM in different modes of Operation.
No need to reconfigure SRAM.
Required PLD Logic is built into the PSD device.
Built-in PLD Logic for Address Decoding. Built-in Page Register.
Integrates Address Latch. EPROM based boot block cannot be corrupted. Partitioned design (MCU+PSD+Flash), easy to develop and debug. One PSD device integrates all logic functions and Boot EPROM. Simple Abel design entry for defining memory map and PLD logic. The PSD device is reprogrammable. Integrated solution requiring smaller PCB and less traces. ZPSD device is a lower overall power solution with higher reliability.
Larger size PCB required.
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Flash Memory - Application Note 048
The PSD Flash Solution
As shown in Figure 1, the basic blocks of a simple partitioned design consists of a ROMless Microcontroller, a PSD device, and a Flash Memory. The Microcontroller interfaces directly to the PSD device. The Flash Memory interfaces to the PSD device through the PSD's I/O ports. The system boots up out of the PSD's EPROM. This boot code should be able to bring the system up to a mode of operation that includes the ability to program the Flash Memory. This includes operation of a serial port to download data into local SRAM. The boot code will also interrogate the Flash Memory to determine which Flash Memory vendor is being used. Since each Flash Memory vendor uses a different programming algorithm, all algorithms will be stored in the PSD's EPROM. This will allow the designer to use the least expensive pin compatible Flash Memory. The PSD's EPROM will store the boot code along with the Flash Memory programming algorithms for all types of Flash Memories being used in production. The PSD's General PLD (GPLD) will be used for address decoding to generate the Flash Memory Chip Selects, to generate upper Flash Memory address lines needed for paging, and serve as additional PLD logic required in the system. The PSD's I/O Ports will be used to latch the address lines when a Microcontroller is used with a multiplexed address/data bus. These I/O Ports will also be used for other port expansion required in the system. The built-in Page Register (not available on the PSD3X1 so use the I/O ports instead) will be used to extend the addressing capabilities of the Microcontroller. When using an 80C31, one bit of the Page Register will be used to change the address map from an Operational Mode to a Programming Mode.
Figure 1. Flash Suppor t Chip Solution
DATA BUS
ADDRESS LINES ADDRESS/ DATA BUS
ROMless MCU
CONTROL SIGNALS
PSDXXX
CONTROL SIGNALS
FLASH MEMORY
80C31 Example
Examples of implementing a Flash Memory with an 80C31 will be shown with both a PSD311 and a PSD411A1. In these examples, an 80C31 is being used with 128 Kbytes of external Flash Memory and 32 Kbytes of SRAM. The memory map during the normal Operational Mode is show in Figure 2. In the Program Space, the PSD's EPROM containing the boot code and programming algorithms along with a portion of Flash Memory are common to all pages of memory. The rest of the Flash Memory is spread over three pages (or banks) of memory. The Data Space is the same for all pages of memory. When programming the Flash Memory, a bit is set in the Page Register to switch the memory map from an Operational Mode to a Programming Mode as shown in Figure 3. The PSD's EPROM that is executing the programming algorithms is still located into the Program Space while the Flash Memory has moved into the Data Space. The 32 Kbytes of SRAM is disabled since the Flash Memory is mapped over it. The external chip selects and the PSD's SRAM and I/O Ports are unaffected and can be accessed on any memory page. While executing from the PSD's EPROM, the system downloads the data from an external Serial Port to the PSD's SRAM. The data is then programmed into the Flash Memory. Note that the chip select to the Flash Memory should cover the programming command addresses (for example, the AMD29010 programming command addresses are 2AAAH and 5555H with A15 = Don't Care). See the Flash Memory vendor's data book for more details.
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Flash Memory - Application Note 048
80C31 Example
(cont.)
Figure 2. Memory Map in Operational Mode with 1 Mbit Flash Memory
Page 0 64K Ext. Flash 32K - 64K 64K Ext. Flash 64K - 96K 32K Ext. Flash 16K - 32K 16K PSD EPROM 0 Page 0 64K 64K 0 Page 1 64K 16K PSD EPROM 0 Page 2 Ext. Flash 16K - 32K 16K PSD EPROM 32K Ext. Flash 16K - 32K Page 1 64K Ext. Flash 96K - 128K Page 2
PROGRAM SPACE
32K
Ext. SRAM
Ext. SRAM 32K 32K Ext. Chip Selects PSD SRAM PSD I/O Ports 16K 4K 2K 0
Ext. SRAM
DATA SPACE
32K 16K 4K 2K 0 Ext. Chip Selects PSD SRAM PSD I/O Ports
16K 4K 2K 0
Ext. Chip Selects PSD SRAM PSD I/O Ports
Figure 3. Memory Map in Programming Mode with 1 Mbit Flash Memory
Page 0 64K 64K Page 1 64K Page 2
PROGRAM SPACE
16K PSD EPROM 0 Page 0 64K Ext. Flash 32K -64K 64K Ext. Flash 64K-96K 32K Ext. Flash 16K - 32K 16K 4K 2K 0 Ext. Chip Selects PSD SRAM PSD I/O Ports 16K 4K 2K 0 Ext. Flash 16K- 32K Ext. Chip Selects PSD SRAM PSD I/O Ports 16K 4K 2K 0 32K Ext. Flash 16K - 32K Ext. Chip Selects PSD SRAM PSD I/O Ports 0 Page 1 64K Ext. Flash 96K-128K 16K PSD EPROM 0 Page 2 16K PSD EPROM
DATA SPACE
32K
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Flash Memory - Application Note 048
80C31 Example
(cont.)
The detailed solution using a PSD311 is shown in Figure 4. The required logic equations are shown in Table 2. When the 80C31 writes a logical "1" to the Program Bit (Port 1, bit 0 on the 80C31), the memory map is switched from the Operational Mode to the Programming Mode as show in Figures 2 and 3. The latched address (A0-7) appears on Port A. Port B provides the control signals along with the upper address lines for the Flash Memory. Controlling the upper two address lines of the Flash Memory allows the PSD to map each 16 Kbytes of Flash Memory anywhere in the 64 Kbyte address space and on any page of the memory map. Since the PSD311 does not have a built-in page register (the PSD312 device has a 4-bit page register), three I/O port pins on the 80C31 are used as a 3bit page register. These signals are routed into the PLD inside the PSD311. Another way to implement the page register in the PSD311 is to use PB0-2 as output pins instead of using the I/O pins on the 80C31. These pins are routed back to the PSD311 through Port C and A19 in the same manner as shown in Figure 4. Note that the PSEN signal is connected to PC2. This will route the PSEN signal into PAD B (or GPLD) for external chip selects. The PSDabel file along with the Fitter Report are shown in Appendix A.
Figure 4. PSD311 with External Flash Memory
80C31/51
EA/VP X1 X2 INT0 INT1 T0 T1 P1 1- 7 TXD RXD P1 0 P1 1 P1 2 P0 0 - 7 P2 0 - 7 RD WR PSEN ALE/ P
ADDRESS / DATA ADDRESS
PSD311
AD0 - 7/A0 - 7 AD8 - 15/A8 - 15 RD WR PSEN ALE PC2 RESET PB0 - 2 A19/CSI PC0 PC1 PB3 PB4 PA0 - 7 PB5 PB6 PB7
EXT. FLASH MEMORY
A16 A15 A8 - A14 A0 - 7
D0 - 7
FLASH_OE FLASH_WR FLASH_CS
RESET
PROGRAM MCU PGR0 MCU PGR1
RESET *
*RESET Signal. The external reset must have a fast rise time from a logic gate, not a slow rise time generated from an RC circuit.
Table 2. Logic Equations for the PSD311
DPLD Equations
rs0 es0 es1 es2 es3 csiop = = = = = = (address > = ^ h0800) (address > = ^ h0000) (address > = ^ h1000) (address > = ^ h2000) (address > = ^ h3000) (address > = ^ h0000) = = = = = & (address & (address & (address & (address & (address & (address < = ^ h0FFF); < = ^ h0FFF); < = ^ h1FFF); < = ^ h2FFF); < = ^ h3FFF); < = ^ h07FF);
GPLD Equations
Flash_A16 Flash_A15 Flash_OE Flash_WR Flash_CS a15 & ((page = = 1) # (page = = 2)); a15 & ((page = = 0) # (page = = 2)); !((!program & !psen) # (program & !rd)); !(program & !wr); !((address > = ^ h4000) & (address < = ^ hFFFF));
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Flash Memory - Application Note 048
80C31 Example
(cont.)
The detailed solution using a PSD411A1 is shown in Figure 5. The PSD411A2 or PSD511B1 can also be used in this example. The required logic equations are shown in Table 3. When the Microcontroller writes a logical "1" to the Page Register Bit 3 at address location ^h0018 (CSIOP + ^h18), the memory map is switched from the Operational Mode to the Programming Mode as shown in Figures 2 and 3. This Page Register is reset to zero when a Reset occurs on the PSD. The latched address (A0-7) appears on Port D. This must be initialized by writing a ^hFF to the Directional Register on Port D (CSIOP + ^h16). Port A provides the control signals along with the upper address lines for the Flash Memory. The PSDabel file along with the Fitter Report are shown in Appendix B. Note that CSIOP = ^h00 in the above two examples (see the definition of CSIOP in the PSDabel file shown in corresponding appendixes).
Figure 5. PSD411/511 with External Flash Memory
DATA ADDRESS
80C31/51
EA/VP X1 X2 INT0 INT1 T0 T1 P1 0 - 7 TXD RXD P0 0- 7 P2 0-7
ADDRESS / DATA ADDRESS
PSD411/511
AD0 -7/A0 -7 AD8 -15/A8 -15 PA0 PA1 PD0 -7
EXT. FLASH MEMORY
A16 A15 A8 - A14 A0 - 7
D0 - 7
RD WR PSEN ALE/ P RESET RESET OUT *
RD WR PE0/PSEN PE1/ALE PE2 RESET CLKIN CSI VSTDBY
PA2 PA3 PA4
FLASH_OE FLASH_WR FLASH_CS
PA5 -7 PB0 -7 PC0 -7 PE3 -7
RESET CLOCK
*RESET OUT Signal is optional. An external reset can be used to make Port Pin PE2 available for other use.
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Flash Memory - Application Note 048
80C31 Example
(cont.)
Table 3. Logic Equations for the PSD411/511
DPLD Equations
rs0 es0 es1 csiop = = = = (address > = ^ h0800) (address > = ^ h0000) (address > = ^ h2000) (address > = ^ h0000) & (address & (address & (address & (address < = ^ h0FFF); < = ^ h1FFF); < = ^ h3FFF); < = ^ h00FF);
GPLD Equations
Flash_A16 Flash_A15 Flash_OE Flash_WR Flash_CS = = = = = a15 & ((page = = 1) # (page = = 2)); a15 & ((page = = 0) # (page = = 2)); !((!program & !psen) # (program & !rd)); !(program & !wr); !((address > = ^ h4000) & (address < = ^ hFFFF));
Conclusion
By using the PSD device as a Flash Memory support chip, the design is simplified into three chips. This solution does not require the programming algorithms to be moved into SRAM and executed from there. By having a separate Boot EPROM, the design is easier to complete and debug. The boot code and programming algorithms are in a secure EPROM technology thus preventing any possibility of the boot sector being corrupted. Any pin compatible Flash Memory can be used without any design change or impact to production. This solution allows a blank Flash Memory to be assembled on the board. By integrating the boot EPROM, PLD logic, and Address Latch into one device, the overall system cost including the impacts on production can be dramatically reduced.
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Flash Memory - Application Note 048
Appendix A
*************************************************************************************** W S I - PSDsoft Version 2.12 PSDabel Design Entry File ***************************************************************************************
module flash311 title ST PSD311 design for External Flash Memory';
"PIN DECLARATIONS "Declare all the pins that are used in the PSD3XX except Port A. "Port A function (latched address out, I/O etc) are defined in the PSD Configuration. "Pin numbers in this design are for the 44 pin PLCC package. "*************************** Bus Interface signals declaration *************************** "The following are multiplexed latched address inputs that are available "as inputs to the PAD. a15,a14,a13,a12,a11 pin 39,38,37,36,35;
"The following are bus control input signals from the 80C31 "In PSD Configuration, you need to select: 8-bit data, mux bus, and "rd, wr, psen signal with active high ale signal rd wr psen ale pin pin pin pin 22; 2; 1; 13; "read line "write line "program space enable "address latch enable
"********************************* Port B pin declaration ********************************* "Port B pins (PB0-PB7) can be configured as: " 1. Input or Output pin. No need to enter equations here for I/O pins. Declare the pin " such that the Fitter will not assign it for PAD output. " 2. PAD output (chip select output). You need to write a logic equation for each of the " PAD output in the .abl file. "Replace the reserved port pin name with your own signal name pb0 pb1 pb2 Flash_A16 Flash_A15 Flash_OE Flash_WR Flash_CS pin 11 ; pin 10 ; pin 9 ; pin 8 ; pin 7 ; pin 6 ; pin 5 ; pin 4 ; "Port "Port "Port "Port "Port "Port "Port "Port B B B B B B B B pin pin pin pin pin pin pin pin pb0 pb1 pb2 pb3 pb4 pb5 pb6 pb7
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Flash Memory - Application Note 048
Appendix A
(cont.)
"************************************* Port C pin declaration ************************************* "Port C pins (PC0-2) pin can be configured as: " 1. Address input (a0-a9), which can be latched by ALE. Input is considered as " address input if it is included in the es0-7 equations. " 2. Logic input to PAD. A logic input participates in PAD output equations only. " 3. PAD output (chip select output). You need to write a logic equation for each of the " PAD outputs in the .abl file. "Replace the reserved port pin name with your own signal name "The following two signals are from the 80C31 I/O ports. These signals indicate what " page of memory is being accessed. This is needed to address the full range "of the 1Mbit Flash Memory. MCU_pgr0 pin 40; "Port C pin pc0 MCU_pgr1 pin 41; "Port C pin pc1 "Connect the external psen signal to PC2. This will route the psen into PAD B "for external chip selects. ext_psen pin 42; "Port C pin pc2
"*********************************** A19/CSI pin declaration *********************************** "The A19/CSI pin can be configured as A19 (address or logic) input or as CSI "(power down). Select the CSI function in the PSD Configuration. Declare A19 here if it is "configured as an address or logic input to the PAD. "Replace the reserved port pin name with your own signal name. "Delete the next line if CSI function is selected. "This is a signal from the 80C31 I/O Port indicating, when high, that the "Flash Memory is in the program mode. program pin 43;
"******************* PAD A Outputs and other internal node declaration *******************
"The following are chip selects for EPROM, SRAM and I/O Port rs0,csiop,es0,es1,es2,es3,es4,es5,es6,es7 node; "The following are Page Register outputs (for PSD3X2, PSD3X3 only). "pgr3, pgr2, pgr1, pgr0 node; "*****************************************************************************************************
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Flash Memory - Application Note 048
Appendix A
(cont.)
"DEFINITIONS X = .x.; "Don't care page = [MCU_pgr1,MCU_pgr0]; "address a10-a0 are not available as inputs to the PAD unless it has been assigned "to Port C pins address = [a15,a14,a13,a12, a11,X,X,X, X,X,X,X, X,X,X,X];
EQUATIONS
"For addresses that are assigned to Port C, they need to be latched by ALE " in the logic equations that follow: "a10.le = ale; a9.le = ale;
"************************************* PAD A equations ************************************* "The PAD A acts as the address decoder and generates chip select signals "that select the internal PSD resources. The address is latched "internally by the ALE. The PSD drives the 8031 data bus only if one of "the select lines and rd or psen are active. "The following equations are examples only. Change the address space to fit "the selected PSD device. "rs0 is the internal PSD SRAM chip select that is active high. "The read and write lines are connected to the SRAM in the PSD so only the address "is necessary in the equation. The SRAM occupies 2KB of memory space and is defined "in 2KB boundaries. rs0 = ((address >= ^h0800) & (address <= ^h0FFF)); "es0-es7 are internal PSD EPROM block chip selects that are active high. "es0-es7 are defined in 4KB, 8KB or 16KB boundaries, depending on the PSD device. "The psen signal is used internally in the PSD to qualify the chip selects "(read can also be used to access the EPROM, see `PSD Configuration'. es0 es1 es2 es3 = = = = ((address ((address ((address ((address >= >= >= >=
^h0000) ^h1000) ^h2000) ^h3000)
& & & &
(address (address (address (address
<= <= <= <=
^h0FFF)) ; ^h1FFF)) ; ^h2FFF)) ; ^h3FFF)) ;
"csiop is the internal PSD chip select for the PSD I/O Port registers and is active high. "csiop takes up 2KB bytes of memory space. Refer to the PSD Data Book "for the address offsets of the registers. csiop = ((address >= ^h0000) & (address <= ^h07FF));
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Flash Memory - Application Note 048
Appendix A
(cont.)
"*************************************** PAD B equations *************************************** "The PAD B can implement up to 9 combinatorial logic outputs. "The number of product terms for the PAD outputs are: "Port B pins pb0-pb3 -- 4 "Port B pins pb4-pb7 -- 2 "Port C pins pc0-pc2 -- 1 "Please VIEW the optimized equation file to find out the number of product terms "used for each output signal definition. "PAD outputs are always enabled by default. Flash_A16 = a15 & ((page == 1) # (page == 2)); Flash_A15 = a15 & ((page == 0) # (page == 2)); Flash_OE = !((!program & !ext_psen) # (program & !rd)); Flash_WR = ! (program & !wr); Flash_CS = !((address >= ^h4000) & (address <= ^hFFFF )); end
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Flash Memory - Application Note 048
Appendix A
(cont.)
********************************************************************************************* W S I - PSDsoft Version 2.12 Output of PSD Fitter *********************************************************************************************
TITLE PROJECT DEVICE FIT OPTION DESCRIPTION : : : : : ST PSD3XX design for External Flash Memory flash3xx DATE: 10/18/1996 PSD311 TIME : 15:06:57 Keep Current Interfacing Ext Flash Memory to the PSD311
*********************************************************************************************
==== Pin Layout for PLDCC/CLDCC Package Type ====
psen wr reset Flash_CS Flash_WR Flash_OE Flash_A15 Flash_A16 pb2 pb1 pb0 ale Line A7 Line A6 Line A5 Line A4 Line A3 Line A2 Line A1 Line A0 rd
Address Address Address Address Address Address Address Address
1] 2] 3] 4] 5] 6] 7] 8] 9] 10] 11] 12] 13] 14] 15] 16] 17] 18] 19] 20] 21] 22]
psen wr reset pb7 pb6 pb5 pb4 pb3 pb2 pb1 pb0 GND ale pa7 pa6 pa5 pa4 pa3 pa2 pa1 pa0 rd
adio0 adio1 adio2 adio3 adio4 adio5 adio6 adio7 adio8 adio9 adio10 GND adio11 adio12 adio13 adio14 adio15 pc0 pc1 pc2 a19/csi VCC
[23 [24 [25 [26 [27 [28 [29 [30 [31 [32 [33 [34 [35 [36 [37 [38 [39 [40 [41 [42 [43 [44
Address/Data Bus ADIO_0 Address/Data Bus ADIO_1 Address/Data Bus ADIO_2 Address/Data Bus ADIO_3 Address/Data Bus ADIO_4 Address/Data Bus ADIO_5 Address/Data Bus ADIO_6 Address/Data Bus ADIO_7 Address Bus ADIO_8 Address Bus ADIO_9 Address Bus ADIO_10 Address Bus Address Bus Address Bus Address Bus Address Bus MCU_pgr2 MCU_pgr1 ext_psen program ADIO_11 ADIO_12 ADIO_13 ADIO_14 ADIO_15 (a11) (a12) (a13) (a14) (a15)
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Appendix A
(cont.)
==== Global Configuration ==== Data Bus Reset Polarity ALE/AS Signal Security Protection Power-down capability (/CSI) EPROM low power mode (CMISER) Track Mode : : : : : : : 8-bit Multiplexed HIGH ACTIVE HIGH OFF Not Used DISABLE OFF
==== Other Configuration === Port A : Pin PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7 Port B : Pin PB0 PB1 PB2 PB3 PB4 PB5 PB6 PB7 Port C : Pin PC0 PC1 PC2 Input/Output Input Input Input Address/Logic Logic Input Logic Input Logic Input IO/Chip Select Output IO IO IO Chip Select Output Chip Select Output Chip Select Output Chip Select Output Chip Select Output CMOS/OD Output CMOS CMOS CMOS CMOS CMOS CMOS CMOS CMOS IO/Address Address Address Address Address Address Address Address Address CMOS/OD Output CMOS CMOS CMOS CMOS CMOS CMOS CMOS CMOS
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Flash Memory - Application Note 048
Appendix A
(cont.)
==== Address & Data Bus Assignment ==== Stimulus Bus Name Signal Description
`adiol = adio[7:0] = Address/Data Bus ADIO_7 - ADIO_0 `adioh = adio[15:8] = Address Bus ADIO_15 - ADIO_8 adio = adio[15:0] = Address/Data Bus ADIO_15 - ADIO_0
===== Resource Usage Summary ===== Device Resources Port A: (pin 14 - pin 21) I/O Pins MCU I/O Address Out Data Port (Non-Mux Bus) Track Mode Port B: (pin 4 - pin 11) I/O Pins MCU I/O PLD Output Data Port (16 bit Non-Mux Bus) Port C: (pin 40 - pin 42) I/O Pins PLD Input PLD Output used / total Percentage
8/ 0/ 8/ 0/ 0/
8 8 8 8 8
100 0 100 0 0
% % % % %
8/ 3/ 5/ 0/
8 8 8 8
100 % 37 % 62 % 0%
3/ 3 3/ 3 0/ 3
100 % 100 % 0%
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Flash Memory - Application Note 048
Appendix A
(cont.)
========= Equations ========= DPLD EQUATIONS : =========================== es0 = !a15 & !a14 & !a13 & !a12; es1 = !a15 & !a14 & !a13 & a12; es2 = !a15 & !a14 & a13 & !a12; es3 = !a15 & !a14 & a13 & a12; es4 = 0; es5 = 0; es6 = 0; es7 = 0; rs0 = !a15 & !a14 & !a13 & !a12 & a11; csiop = !a15 & !a14 & !a13 & !a12 & !a11; PORT B EQUATIONS : =================== !Flash_A16 = !a15 # MCU_pgr0 & MCU_pgr1 # !MCU_pgr0 & !MCU_pgr1; !Flash_A15 = !a15 # MCU_pgr0; !Flash_OE = !rd & program # !ext_psen & !program; !Flash_WR = ! wr & program; !Flash_CS = a15 # a14; PORT C EQUATIONS : ===================
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Appendix B
********************************************************************************************* W S I - PSDsoft Version 2.12 PSDabel Design Entry File *********************************************************************************************
module flash411A1 title ST PSD4XX/5XX design for External Flash'; "PIN DECLARATIONS "Declare all the pins that are used in the PSD4XX/5XX. "********************* Bus Interface signals declaration ********************* "The following are multiplexed latched address inputs that are available as inputs "to the ZPLD. a9,a8,a1,a0 a15,a14,a13,a12,a11,a10 pin 67,68,8,9; pin 61,62,63,64,65,66;
"The following are bus control input signals from the 80C31 "In PSDConfiguration, you need to select:8-bit data, mux bus, and "rd, wr, psen signal with active high ale. rd wr psen ale reset csi clkin pin 41; pin 29; pin 38; pin 37; pin 40; pin 39; pin 42; "read line "write line "program space enable "address latch enable "reset input, active low "PSD chip select, grounded if pin is not used "clock input, optional
"**************************** Port A, B, C, D, E pin declaration **************************** "The following are I/O Port pin assignments. Port functions that need "to be declared here are: " 1. latched address output a0-a7 (Port C or D) " 2. other address inputs: a2-a7 (Port A) " 3. MCU inputs/outputs " 4. GPLD inputs/outputs "Your software needs to set up the appropriate registers to enable Port functions such as "the latched address and MCU I/O (see I/O section in the PSD Data Book for instructions). "No equations are required if the pins are declared for non-GPLD function. "If GPLD output is an internal feedback, you can assign it as a `node', where the node "number is the same as the pin number. "For PLD pins: you may want the PSD Fitter to assign the pins for you for complex logic "functions. In that case you need only to declare the PLD signal as `pin' and omit "the pin number.
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Flash Memory - Application Note 048
Appendix B
(cont.)
"psd4xxa1: Port A and B pins can be defined as PLD input or output "psd4xxa2/psd5xxb1: Port A, B and E pins can be defined as PLD input or output " Port C and D pins are PLD input only "Replace the reserved port pin name with your own signal name "Port A pin assignments Flash_A16 Flash_A15 Flash_OE Flash_WR Flash_CS pa5 pa6 pa7 pin pin pin pin pin pin pin pin 27; 26; 25; 24; 23; 22; 21; 20; "Port A pin pa0 "Port A pin pa1 "Port A pin pa2 "Port A pin pa3 "Port A pin pa4 "Port A pin pa5 "Port A pin pa6 "Port A pin pa7
"Port B pin assignments pb0 pb1 pb2 pb3 pb4 pb5 pb6 pb7 pin pin pin pin pin pin pin pin 50; 49; 48; 47; 46; 45; 44; 43; "Port "Port "Port "Port "Port "Port "Port "Port B pin B pin B pin B pin B pin B pin B pin B pin pb0 pb1 pb2 pb3 pb4 pb5 pb6 pb7
"Port C pin assignments "If Port C is assigned for latched address output, use signal names "such as addr0-addr7 (a0, a1 etc. are reserved names). You need "to set up the Control and Direction registers during run time "to enable this function. pc0 pc1 pc2 pc3 pc4 pc5 pc6 pc7 pin pin pin pin pin pin pin pin 17; 16; 15; 14; 13; 12; 11; 10; "Port "Port "Port "Port "Port "Port "Port "Port C pin pc0 C pin pc1 C pin pc2 C pin pc3 C pin pc4 C pin pc5 C pin pc6 C pin pc7
"Port D pin assignments pd0 pd1 pd2 pd3 pd4 pd5 pd6 pd7 pin pin pin pin pin pin pin pin 60; 59; 58; 57; 56; 55; 54; 53; "Port "Port "Port "Port "Port "Port "Port "Port D pin pd0 D pin pd1 D pin pd2 D pin pd3 D pin pd4 D pin pd5 D pin pd6 D pin pd7
3-36
Flash Memory - Application Note 048
Appendix B
(cont.)
"Port E pin assignments; pe0-1 are used as psen and ale inputs, respectively pe2 pe3 pe4 pe5 pe6 pe7 pin pin pin pin pin pin 36; 34; 33; 32; 31; 30; "Port "Port "Port "Port "Port "Port E pin pe2 E pin pe3 E pin pe4 E pin pe5 E pin pe6 E pin pe7
"**************** DPLD Outputs and other internal node declaration **************** "The following are DPLD outputs (chip selects) for EPROM, SRAM & I/O Port rs0,es0,es1,es2,es3,csiop node; "The following are Page Register outputs; they can be used as a data "latch for GPLD input if paging is not needed pgr3, pgr2, pgr1, pgr0 node; "Use the pgr3 bit to determine if the system is in the flash program mode or the "operational mode. When this bit is a one, the system is in the flash program mode.
"DEFINITIONS X = .x.; "Don't care clk = .c.; "Clock pulse page = [pgr1,pgr0]; program = pgr3; "address a7-a2 are not available as inputs to the GPLD unless "it has been assigned to Port A pins address = [a15,a14,a13,a12,a11,a10,a9,a8,X,X,X,X,X,X,a1,a0];
EQUATIONS
"If a7-a2 are assigned to Port A, they need to be latched by ALE in the "logic equations that follow: "a7.le = ale; a6.le = ale;
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Flash Memory - Application Note 048
Appendix B
(cont.)
"***************************************** DPLD equations ***************************************** "The DPLD acts as the address decoder and generates chip select signals "that select the internal PSD resources. The address is latched internally by the ALE. "The PSD drives the data bus only if one of the select lines and rd or psen are active. "The following DPLD equations are examples only. Change the address space "to fit the selected PSD device. "rs0 is the internal PSD SRAM chip select that is active high. "The read and write lines are connected to the SRAM in the PSD "so only the address is necessary in the equation. The SRAM "occupies 2KB of memory space and is defined in 2KB boundaries. rs0 = ((address >= ^h0800) & (address <= ^h0FFF)); "es0-es3 are internal PSD EPROM block chip selects that are active high. "The psen signal is used internally in the PSD to qualify these chip selects. es0 = ((address >= ^h0000) & (address <= ^h1FFF)) ; es1 = ((address >= ^h2000) & (address <= ^h3FFF)) ;
"csiop is the internal PSD chip select for all of the PSD configuration "and I/O registers. csiop takes up 256 bytes of memory space and is active "high. See `System Configuration Section' in the PSD Data Book for the "address offsets of the registers. csiop = ((address >= ^h0000) & (address <= ^h00FF));
"************************************** GPLD equations ************************************** Flash_A16 = a15 & ((page == 1) # (page == 2)); Flash_A15 = a15 & ((page == 0) # (page == 2)); Flash_OE = !((!program & !psen) # (program & !rd)); Flash_WR = !(program & ! wr); Flash_CS = !((address >= ^h4000) & (address <= ^hFFFF));
end
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Flash Memory - Application Note 048
Appendix B
(cont.)
********************************************************************************************** W S I - PSDsoft Version 2.12 Output of PSD Fitter *********************************************************************************************
TITLE : ST PSD4XX/5XX design for External Flash PROJECT : Flash4xx DATE : 10/18/1996 DEVICE : PSD411A1 TIME : 15:08:44 FIT OPTION : Keep Current DESCRIPTION: Interfacing Flash Memory to the PSD411A1 *************************************************************************** ==== Pin Layout for PLDCC/CLDCC Package Type ====
GND Address/Data Bus ADIO_7 Address/Data Bus ADIO_6 Address/Data Bus ADIO_5 Address/Data Bus ADIO_4 Address/Data Bus ADIO_3 Address/Data Bus ADIO_2 Address/Data Bus ADIO_1 (a1) Address/Data Bus ADIO_0 (a0) pC7 pC6 pC5 pC4 pC3 pC2 pC1 pC0
pa7 pa6 pa6 Flash_CS Flash_WR Flash_OE Flash_A15 Flash_A16 wr pe7 pe6 pe5 pe4 pe3
1] 2] 3] 4] 5] 6] 7] 8] 9] 10] 11] 12] 13] 14] 15] 16] 17] 18] 19] 20] 21] 22] 23] 24] 25] 26] 27] 28] 29] 30] 31] 32] 33] 34]
GND adio7 adio6 adio5 adio4 adio3 adio2 adio1 adio0 pC7 pC6 pC5 pC4 pC3 pC2 pC1 pC0 VCC GND pa7 pa6 pa5 pa4 pa3 pa2 pa1 pa0 VSTBY wr pe7 pe6 pe5 pe4 pe3
GND pe2 pe1 pe0 csi reset rd clkin pb7 pb6 pb5 pb4 pb3 pb2 pb1 pb0 adio15 GND pd7 pd6 pd5 pd4 pd3 pd2 pd1 pd0 adio15 adio14 adio13 adio12 adio11 adio10 adio9 adio8
[35 [36 [37 [38 [39 [40 [41 [42 [43 [44 [45 [46 [47 [48 [49 [50 [51 [52 [53 [54 [55 [56 [57 [58 [59 [60 [61 [62 [63 [64 [65 [66 [67 [68
pe2 ale psen csi reset rd clkin pb7 pb6 pb5 pb4 pb3 pb2 pb1 pb0
pd7 pd6 pd5 pd4 pd3 pd2 pd1 pd0 Address Address Address Address Address Address Address Address
Bus Bus Bus Bus Bus Bus Bus Bus
ADIO_15 (a15) ADIO_14 (a14) ADIO_13 (a13) ADIO_12 (a12) ADIO_11 (a11) ADIO_10 (a10) ADIO_9 (a9) ADIO_8 (a8)
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Flash Memory - Application Note 048
Appendix B
(cont.)
==== Global Configuration ==== Data Bus : 8-bit Multiplexed ALE/AS Signal : ACTIVE HIGH Security Protection : OFF ==== Address & Data Bus Assignment ==== Stimulus Bus Name Signal Description
`adiol = adio[7:0] = Address/Data Bus ADIO_7 - ADIO_0 `adioh = adio[15:8] = Address Bus ADIO_15 - ADIO_8 adio = adio[15:0] = Address/Data Bus ADIO_15 - ADIO_0 ===== Resource Usage Summary ===== Device Resources Port A: (pin 20 - pin 27) I/O Pins MCU I/O or Address Out Peripheral I/O ZPLD Inputs ZPLD Combinatorial Outputs Other Information Buried Macrocells Product Terms Port B: (pin 43 - pin 50) I/O Pins MCU I/O or Address Out ZPLD Inputs ZPLD Combinatorial Outputs ZPLD Registered Outputs Other Information Buried Macrocells Product Terms Port C: (pin 10 - pin 17) I/O Pins MCU I/O or Address Out Data Port (Non-Mux Bus) Port D: (pin 53 - pin 60) I/O Pins MCU I/O or Address Out Data Port (16-bit Non-Mux Bus) Port E: (pin 30 - pin 34, pin 36 - pin 38) I/O Pins MCU I/O or Address Out ZPLD Inputs Control Signal Inputs APD Clock Input used / total Percentage
8 3 0 0 5
/ / / / /
8 8 8 8 8
100 % 37 % 0% 0% 62 % 0% 28 %
0/ 3 7 / 25
8/ 8/ 0/ 0/ 0/
8 8 8 8 8
100 % 100 % 0% 0% 0% 0% 0%
0/ 8 0 / 80
8/ 8 8/ 8 0/ 8
100 % 100 % 0%
8/ 8 8/ 8 0/ 8
100 % 100 % 0%
8/ 6/ 0/ 2/ 0/
8 8 2 2 1
100 % 75 % 0% 100 % 0%
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Flash Memory - Application Note 048
Appendix B
(cont.)
==== OMC Resource Assignment ==== Resources Used Port A : macro cell 0 macro cell 1 macro cell 2 macro cell 3 macro cell 4 Port B : ========= Equations ========= DPLD EQUATIONS : =================== es0 es1 es2 es3 rs0 csiop = = = = = = !a15 & !a14 & !a13; !a15 & !a14 & a13; 0; 0; !a15 & !a14 & !a13 & !a12 & a11; !a9 & !a8 & !a15 & !a14 & !a13 & !a12 & !a11 & !a10; User Name
Flash_A16 (mc_pa0) => Combinatorial Flash_A15 (mc_pa1) => Combinatorial Flash_OE (mc_pa2) => Combinatorial Flash_WR (mc_pa3) => Combinatorial Flash_CS (mc_pa4) => Combinatorial
PORT A EQUATIONS : =================== Flash_A16 = a15 & !pgr1 & pgr0 # a15 & pgr1 & !pgr0; Flash_A15 = a15 & !pgr0; Flash_OE = rd & pgr3 # psen & !pgr3; !Flash_WR = !wr & pgr3; Flash_CS = !a15 & !a14; [Flash_A16, Flash_A15, Flash_OE, Flash_WR, Flash_CS].OE = 1; PORT B EQUATIONS : ===================
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AN1422 - APPLICATION NOTE
Table 1. Document Revision History
Date Rev. 1.0 Description of Revision AN048: Document written in the WSI format AN1422: Designing with Flash+PSD Memory Front page, and back two pages, in ST format, added to the PDF file Any references to Waferscale, WSI, EasyFLASH and PSDsoft 2000 updated to ST, ST, Flash+PSD and PSDsoft Express
30-Jan-2002
1.1
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AN1422 - APPLICATION NOTE
For current information on PSD products, please consult our pages on the world wide web: www.st.com/psm If you have any questions or suggestions concerning the matters raised in this document, please send them to the following electronic mail addresses: apps.psd@st.com ask.memory@st.com (for application support) (for general enquiries)
Please remember to include your name, company, location, telephone number and fax number.
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the co nsequences of use of such information nor for any infringement of patents or other rights ofthird parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publicati on are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics prod ucts are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectro nics. The ST logo is registered trademark of STMicroelectronics All other names are the property of their respective owners (c) 2002 STMicroelectronics - All Rights Reserved STMicroelectronics group of companies Australia - Brazil - Canada - China - Finland - France - Germany - Hong Kong India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - Unit www.st.com ed States.
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