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CML Semiconductor Products
CTCSS/DCS/SELCALL Processor
FX828
D/828/3 July 1997 Provisional Issue
1.0
Features
* * * * *
Fast CTCSS Detection Full 23/24 Bit DCS Codec Non-Predictive Tone Detection Low Power 3.3V/5V Operation Variable Gain Audio Filter
* * * * *
Programmable Tone Decoder Programmable Comparator for RSSI Programmable Modulator Drivers Programmable Tone Encoders Full Duplex CTCSS and Selcall
1.1
Brief Description
The FX828 is an innovative CTCSS, DCS and Selcall Codec, designed for the latest generation of Land Mobile Radio equipment. Designed to complement the FX829, the FX828 has many advanced features which assist the operation of modern SUBAUDIO and INBAND based signalling systems. The FX828 is electrically, physically and software compatible with the FX818 and FX829. It permits manufacturers to add new features to their equipment with minimal design changes. The FX828 incorporates a programmable tone decoder which can be set to respond to between 1 and 15 CTCSS or Selcall tones with minimum software intervention. In addition, a 'Fast' CTCSS detector can respond to a single programmed tone in 60 ms, or can be used to provide an output if any CTCSS tone is present at the detector input. Two high resolution tone encoders perform accurate generation of any CTCSS or Selcall tone in current use. Full 23 or 24 bit DCS encoding and decoding complements the CTCSS/Selcall line-up. A timer is included which, for example, may be used for timing Selcall transmissions and a comparator is provided to assist with carrier or RSSI monitoring. The device can operate full duplex in all operating modes except for DCS. The FX828 along with the FX818 and FX829 is offered in a choice of small SSOP, DIL and SOIC 24-pin packages. It may be used with 3.0 to 5.5 volt supply.
(c) 1997 Consumer Microcircuits Limited
CTCSS/DCS/SELCALL Processor
FX828
CONTENTS Section Page
1.0 Features .......................................................................................................... 1 1.2 Block Diagram ................................................................................................ 3 1.3 Signal List ....................................................................................................... 4 1.3 Signal List ....................................................................................................... 4 1.4 External Components .................................................................................... 6 1.4 External Components .................................................................................... 6 1.5 General Description ....................................................................................... 7 1.5.1 Software Description ..................................................................... 7 1.6 Application Notes......................................................................................... 20 1.6.1 General .......................................................................................... 20 1.6.2 Transmitter ................................................................................... 20 1.6.3 Receiver (Decode) ........................................................................ 21 1.6.4 Receiver (Fast Detect) ................................................................. 21 1.6.5 Receiver (DCS Decoder) .............................................................. 21 1.6.6 General Purpose Timer................................................................ 22 1.6.7 Full Duplex Modes ....................................................................... 22 1.6.8 Tx / Fast Rx Tone Table ............................................................... 23 1.6.9 Rx Program Tone Table............................................................... 23 1.6.10 Tx Tone Program Table : Selcall............................................... 24 1.6.11 Rx Tone Program Table : Selcall .............................................. 25 1.6.12 Tx DCS Code Table .................................................................... 26 1.7 Performance Specification .......................................................................... 27 1.7.1 Electrical Performance ................................................................ 27 1.7.2 Packaging ..................................................................................... 33
Note:
As this product is still in development, it is likely that a number of changes and additions will be made to this specification. Items marked TBD or left blank will be included in later issues.
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.2
Block Diagram
Figure 1 Block Diagram
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.3
Signal List
Signal Name XTALN XTAL/CLOCK Type O/P I/P The inverted output of the on-chip oscillator. The input to the on-chip oscillator, for external Xtal circuit or clock. The "C-BUS" serial clock input. This clock, produced by the Controller, is used for transfer timing of commands and data to and from the device. See "C-BUS" Timing Diagram (Figure 4). The "C-BUS" serial data input from the Controller. Data is loaded into this device in 8-bit bytes, MSB (B7) first, and LSB (B0) last, synchronised to the SERIAL CLOCK. See "C-BUS" Timing Diagram (Figure 4). The "C-BUS" serial data output to the Controller. The transmission of REPLY DATA bytes is synchronised to the SERIAL CLOCK under the control of the CSN input. This 3-state output is held at high impedance when not sending data to the Controller. See "C-BUS" Timing Diagram (Figure 4). The "C-BUS" data loading control function: this input is provided by the Controller. Data transfer sequences are initiated, completed or aborted by the CSN signal. See "C-BUS" Timing Diagram (Figure 4). This output indicates an interrupt condition to the Controller by going to a logic "0". This is a "wire-ORable" output, enabling the connection of up to 8 peripherals to 1 interrupt port on the Controller. This pin has a low impedance pulldown to logic "0" when active and a highimpedance when inactive. An external pullup resistor is required. The conditions that cause interrupts are indicated in the IRQ FLAG register and are effective if not masked out by a corresponding bit in the IRQ MASK register. Description
Package D2/D5/P4 Pin No. 1 2
3
SERIAL CLOCK
I/P
4
COMMAND DATA
I/P
5
REPLY DATA
O/P
6
CSN
I/P
7
IRQN
O/P
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.3
Signal List (continued)
Signal Name COMPOUT COMPIN A/D CAP 1 Type O/P I/P O/P The output of the comparator. The input to the comparator. An internal reference voltage for the CTCSS A to D. Decouple to VSS with an external capacitor. An internal reference voltage for the DCS A to D. Decouple to VSS with an external capacitor. The negative supply rail (ground). A bias line for the internal circuitry, held at 1/2 VDD. This pin must be decoupled by a capacitor mounted close to the device pins. The inverting input to the Rx input amplifier. The output of the Rx input amplifier and the input to the audio filter section. Output of the Rx audio filter section. Output of the selcall tone generator. Input to the audio summing amplifier. Output of the audio summing amplifier. Input to MOD1 audio gain control. Output of the CTCSS or DCS Tx tone generator. Output of MOD1 audio gain control. Output of MOD2 audio gain control. The positive supply rail. Levels and voltages are dependent upon this supply. This pin should be decoupled to VSS by a capacitor. Description
Package D2/D5/P4 Pin No. 8 9 10
11
A/D CAP 2
O/P
12 13
Vss VBIAS
Power O/P
14 15
RX AMP IN RX AMP OUT
I/P O/P
16 17 18 19 20 21 22 23 24
RX AUDIO OUT TX AUDIO OUT SUM IN SUM OUT MOD1 IN TX SUB AUDIO OUT MOD1 MOD2 VDD
O/P O/P I/P O/P I/P O/P O/P O/P Power
Notes: I/P = O/P =
Input Output
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.4
External Components
C1 C2 C3 C4 C5 C6 C7 C8 C9 Notes:
22pF 22pF 100pF 0.1F 100pF 0.1F Note 2 0.1F 1.0 to 3.3F
20% 20% 20% 20% 20% 20% 20% 20% 20%
R1 R2 R3 R4 R5 R6 R7
1M 100k 100k Note 2 22k Note 1 Note 1
5% 10% 10% 10% 10% 10% 10%
X1
4.032MHz (tolerance depends upon system requirements)
1. R2, R6, R7 and C3 form the gain components for the Summing Amplifier. R6 and R7 should be chosen as required from the system specification, using the following formula: Tx Sub Audio Gain Tx Audio Gain =- =-
R2 R6 R2 R7
2. R3, R4, C5 and C7 form the gain components for the Rx Input Amplifier. R4 should be chosen as required by the signal level, using the following formula: Gain =-
R3 R4
C7 x R4 should be chosen so as not to compromise the low frequency performance of this product. Figure 2 Recommended External Components
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.5
General Description
The FX828 is a signalling encoder/decoder for use in land mobile radio equipment, see Figure 1. The transmitter section of this device has independently controllable tone generators for sub-audio (CTCSS) and inband (Selcall) signalling. It also features a DCS code generator, which may be used in place of the CTCSS tone generator. The receiver section of the FX828 has a fast/predictive CTCSS tone detector which operates in parallel with a DCS decoder and a CTCSS/Selcall tone decoder. The latter is switchable to perform either CTCSS or Selcall tone decoding of a user-programmable set of up to 15 tones. In the CTCSS mode it performs a more accurate (but slower) analysis of the tones detected by the fast/predictive CTCSS tone detector, which is a single detector that is switchable to provide either a fast response to any CTCSS tone (FAST DETECT mode) or a fast response to a single user-programmed CTCSS tone (PREDICTIVE mode). Other functions on the FX828 are a comparator with programmable threshold level, a general purpose timer and a summing amplifier with two adjustable gain blocks, which may be used for two point modulation, for example. All FX828 functions are controlled by an external C over the C-BUS interface, a serial interface designed to reduce interference levels in radio equipment.
1.5.1
Software Description Address/Commands Instructions and data are transferred, via "C-BUS", in accordance with the timing information given in Figure 4. Instruction and data transactions to and from the FX828 consist of an Address/Command (A/C) byte followed by either: (i) (ii) a further instruction or data (1 or 2 bytes) or a status or Rx data reply (1 byte)
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
8-bit Write Only Registers
HEX ADDRESS/ COMMAND REGISTER NAME BIT 7 (D7) BIT 6 (D6) BIT 5 (D5) BIT 4 (D4) BIT 3 (D3) BIT 2 (D2) BIT 1 (D1) BIT 0 (D0)
$01
GENERAL RESET
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
$80
SIGNALLING CONTROL
SUBAUDIO TX ENABLE
TONE DECODER ENABLE
FAST DETECT ENABLE
0
0 FAST CTCSS MODE DETECT/ PREDICTIVE
SELCALL TX ENABLE
0
DCS RX ENABLE
TONE DECODER BANDWIDTH
$82 SIGNALLING SET-UP MSB BIT 3 BIT 2 BIT 1 LSB BIT 0
TONE DECODER MODE
SUBAUDIO TX MODE
DCS 23/24
DCS BYTE 3
$85 DCS BYTE 3 OPTIONAL MSB BIT 23 BIT 22 BIT 21 BIT 20 BIT 19 BIT 18 BIT 17 BIT 16
DCS BYTE 2
$86 DCS BYTE 2 BIT 15 BIT 14 BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8
DCS BYTE 1
$87 DCS BYTE 1 BIT 7 BIT 6 BIT 5 BPF $88 GENERAL CONTROL GENERAL $8B PURPOSE TIMER MSB BIT 7 BIT 6 GP TIMER $8E IRQ MASK 0 IRQ MASK BIT 5 COMP 0 to 1 IRQ MASK BIT 4 COMP 1 to 0 IRQ MASK BIT 3 TONE IRQ MASK BIT 2 CTCSS FAST IRQ MASK 0 BIT 1 BPF ENABLE BPF UN-MUTE 6dB PAD BIT 4 MSB DAC BIT 2 DAC BIT 1 BIT 3 BIT 2 LSB DAC BIT 0 GP TIMER ENABLE GP TIMER RE-CYCLE BIT 1 LSB BIT 0
GENERAL PURPOSE TIMER
LSB BIT 0 DCS IRQ MASK
$9C
Reserved for later use
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
16-bit Write Only Registers
HEX ADDRESS/ COMMAND REGISTER NAME CTCSS TX/ $83 FAST RX FREQUENCY (1) CTCSS TX/ FAST RX FREQUENCY (2) RX TONE $84 PROGRAM (1) RX TONE PROGRAM (2) AUDIO $8A CONTROL (1) AUDIO CONTROL (2) 0 0 MOD 2 ENABLE MSB BIT 4 BIT 3 BIT 2 BIT 1 0 0 MOD 1 ENABLE MSB BIT 4 BIT 3 BIT 2 BIT 1 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 MSB BIT 3 BIT 2 BIT 1 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 CTCSS (TX) NOTONE 0 0 MSB BIT 12 BIT 11 BIT 10 BIT 9 BIT 8 BIT 7 (D7) BIT 6 (D6) BIT 5 (D5) BIT 4 (D4) BIT 3 (D3) BIT 2 (D2) BIT 1 (D1) BIT 0 (D0)
CTCSS TX/FAST RX FREQUENCY
CTCSS TX/FAST RX FREQUENCY
LSB BIT 0
TONE ADDRESS
LSB BIT 0 MSB BIT 11
TONE FREQUENCY
BIT 10 BIT 9 BIT 8
TONE FREQUENCY
LSB BIT 0
MOD 1
LSB BIT 0
MOD 2
LSB BIT 0
SELCALL TX TONE
$8D SELCALL TX (1) SELCALL NOTONE 0 0 MSB BIT 12 BIT 11 BIT 10 BIT 9 BIT 8
SELCALL TX TONE
SELCALL TX (2) BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 LSB BIT 0
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
Write Only Register Description GENERAL RESET (Hex address $01) The reset command has no data attached to it. It sets the device registers into the specific (all powersaved) states as listed below:
REGISTER NAME SIGNALLING CONTROL SELCALL & SUB-AUDIO STATUS SIGNALLING SET-UP CTCSS TX / FAST RX FREQUENCY CTCSS TX / FAST RX FREQUENCY RX TONE PROGRAM RX TONE PROGRAM DCS BYTE 3 DCS BYTE 2 DCS BYTE 1 GENERAL CONTROL AUDIO CONTROL AUDIO CONTROL GENERAL PURPOSE TIMER SELCALL TX SELCALL TX IRQ MASK IRQ FLAG HEX ADDRESS $80 $81 $82 $83 BIT 7 (D7) 0 0 0 0 0 $84 $85 $86 $87 $88 $8A $8B $8D $8E $8F 0 0 0 0 0 0 0 0 0 0 0 0 0 BIT 6 (D6) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BIT 5 (D5) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BIT 4 (D4) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BIT 3 (D3) 0 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BIT 2 (D2) 0 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BIT 1 (D1) 0 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 BIT 0 D0) 0 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
(1) (2) (1) (2)
(1) (2) (1) (2)
X = undefined SIGNALLING CONTROL Register (Hex address $80) This register is used to control the functions of the device as described below: SUBAUDIO TX ENABLE (Bit 7) TONE DECODER ENABLE (Bit 6) Bit 7 should be set to "1" to enable the CTCSS/DCS subaudio transmitter. The subaudio Tx type will depend on the state of the SUBAUDIO TX MODE (Bit 1 SIGNALLING SET-UP Register $82). Bit 6 should be set to "1" to enable the CTCSS/Selcall tone decoder or the DCS decoder. Note: See also Bit 0 for DCS decoder operation. Bits 7 and 6 should not both be set to "1" when Bit 0 is set to "1" because the DCS function is half-duplex only. CTCSS FAST DETECT ENABLE (Bit 5) When this bit is "1", the FAST CTCSS DETECT or FAST CTCSS PREDICTIVE mode is enabled, depending upon the setting of FAST CTCSS MODE (Bit 3 SIGNALLING SET-UP Register, $82). When this bit is "0", both FAST CTCSS DETECT and FAST CTCSS PREDICTIVE tone detectors are disabled. When this bit is "1" the Selcall transmitter is enabled. When this bit is "0" the Selcall transmitter is disabled and powersaved.
SELCALL TX ENABLE (Bit 2) DCS RX ENABLE (Bit 0)
When this bit is "1" and Bit 6 is "1", the DCS decoder is enabled. When this bit is "0" the DCS decoder is disabled. The DCS decoder and the subaudio (CTCSS or DCS) transmitter should not be enabled at the same time.
(Bits 4, 3, and 1)
Reserved for future use. These bits should be set to "0".
10 D/828/3
(c) 1997 Consumer Microcircuits Limited
CTCSS/DCS/SELCALL Processor
FX828
SIGNALLING SET-UP Register (Hex address $82) This register is used to define the signalling parameters, as described below: TONE DECODER BANDWIDTH (Bits 7, 6, 5 and 4) These four bits set the bandwidth of the CTCSS/Selcall tone decoder according to the table below:
Recommended for CTCSS Recommended for CCIR
Recommended for ZVEI
Bit 7 1 1 1 1 1 1 1 1
Bit 6 0 0 0 0 1 1 1 1
Bit 5 0 0 1 1 0 0 1 1
Bit 4 0 1 0 1 0 1 0 1
BANDWIDTH Will Decode Will Not Decode 1.1% 2.4% 1.3% 2.7% 1.6% 2.9% 1.8% 3.2% 2.0% 3.5% 2.2% 3.7% 2.5% 4.0% 2.7% 4.2%
FAST CTCSS MODE (Bit 3)
When CTCSS FAST DETECT ENABLE (Bit 5 SIGNALLING CONTROL Register, $80) is "1", this bit selects the FAST CTCSS DETECT or the FAST CTCSS PREDICTIVE mode, according to the table below: DETECT/ PREDICTIVE Bit 3 0 1
Function DETECT mode PREDICTIVE mode
If the CTCSS FAST DETECT ENABLE bit is "0" then both modes are deselected. TONE DECODER MODE (Bit 2) SUBAUDIO TX MODE (Bit 1) When this bit is "1" the CTCSS/Selcall tone decoder is set to detect inband (Selcall) tones. When this bit is "0" the tone decoder is set to detect subaudio (CTCSS) tones. When this bit is "1" the subaudio transmitter will be set to transmit DCS signals, if enabled. When this bit is "0" the subaudio transmitter will be set to transmit CTCSS signals, if enabled. When this bit is "1" the DCS transmitter and decoder are configured for a 23-bit code. When this bit is "0" they are configured for a 24-bit code.
DCS 23/24 (Bit 0)
DCS BYTE 3 Register (Hex address $85) DCS BYTE 2 Register (Hex address $86) DCS BYTE 1 Register (Hex address $87) These three bytes set the code that is transmitted or received in the DCS mode. The LSB bit "0" of the DCS BYTE 1 is transmitted first and the last bit is the MSB bit 23 of DCS BYTE 3 in the 24-bit mode or bit 22 in the 23-bit mode.
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
GENERAL CONTROL Register (Hex address $88) This register is used to control the functions of the device as described below: BPF ENABLE (Bit 7) BPF UN-MUTE (Bit 6) When this bit is "1" the audio band-pass filter is enabled. When this bit is "0" the audio band-pass filter is disabled (powersaved). When this bit is "1" the audio band-pass filter output is switched to the RX AUDIO OUT pin. When this bit is "0" the output of the filter is disconnected from RX AUDIO OUT, which is then in a high impedance state. This control, along with BPF ENABLE, allows the filter to power up and settle internally before switching the output on, to avoid clicks when coming out of powersave. BPF 6dB PAD (Bit 5) When this bit is "1" a 6dB attenuator is inserted into the output of the audio band-pass filter. When this bit is "0" the output of the audio band-pass filter is not attenuated. These three bits set the level of the digital to analogue converter that feeds the negative input of the comparator. The DAC can be set to one of eight levels equally spaced between VSS and VBIAS, not including VSS, but including VBIAS, i.e. with a 5V supply, the lowest level would be 312.5mV set by "000" in bits 2, 3 and 4 and the highest level would be 2.5V set by "111" in bits 2, 3 and 4. When this bit goes to a "1" the general purpose timer is restarted and its internal register is re-loaded from the value specified in the GENERAL PURPOSE TIMER Register (Hex address $8B). It will then count down from the count held in its internal register. When this bit is "0" the count down is disabled and the last pre-programmed value is retained in the timer's internal register. When this bit is "1" the general purpose timer will re-load its internal register from the value specified in the GENERAL PURPOSE TIMER Register (Hex Address $8B) when the count in the internal register reaches zero (i.e. the timeout has expired). It then restarts the count down, so that the timer continuously cycles. When this bit is "0" the general purpose timer will stop when the count in the internal register reaches zero (i.e. the timeout has expired). The timer can only be restarted by reloading a value into the GENERAL PURPOSE TIMER Register (Hex address $8B). If this bit is switched from "1" to "0" whilst the timer is enabled then the timer will complete the present count before stopping.
DAC (Bits 4, 3 and 2)
TIMER ENABLE (Bit 1)
TIMER RE-CYCLE (Bit 0)
GENERAL PURPOSE TIMER (GPT) Register (Hex address $8B) This register is used to preset the value of a countdown timer. Once a binary value has been loaded into this register, it will be automatically transferred to an internal register within the timer. This internal register is then decremented at each count interval (1ms) until it reaches zero. On reaching zero, the GPT IRQ FLAG in the IRQ FLAG Register (Hex address $8F) is set to "1". An interrupt is generated on the IRQN pin if the GPT IRQ MASK in the IRQ MASK Register (Hex address $8E) is "1" otherwise the GPT IRQ FLAG remains set to "1" and no interrupt is generated.
(c) 1997 Consumer Microcircuits Limited
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CTCSS/DCS/SELCALL Processor
FX828
When the internal register has reached a count of zero, the action of the timer depends on the setting of the TIMER RE-CYCLE bit in the GENERAL CONTROL Register (Hex address $88). If the TIMER RE-CYCLE bit is "1" then the timer will re-load the countdown value from the GENERAL PURPOSE TIMER Register and restart the countdown from this value. If the TIME RE-CYCLE bit is "0" then the timer will stop and no further action or timer interrupts will take place until the GENERAL PURPOSE TIMER Register is re-loaded. Loading the GENERAL PURPOSE TIMER with "0" will cause the timer circuitry to be disabled (i.e. powersaved). IRQ MASK Register (Hex address $8E) This register is used to control the interrupts (IRQs) as described below: (Bits 7 and 1) GPT IRQ MASK (Bit 6) Reserved for future use. These should be set to "0". When this bit is set to "1" it enables an interrupt that occurs when GPT IRQ FLAG (Bit 6, IRQ FLAG Register, $8F) changes from "0" to "1". When this bit is "0" the interrupt is masked. When this bit is set to "1" it enables an interrupt that occurs when the comparator output goes from "0" to "1". When this bit is set to "0" the interrupt is masked. When this bit is set to "1" it enables an interrupt that occurs when the comparator output goes from "1" to "0". When this bit is set to "0" the interrupt is masked. When this bit is set to "1" it enables an interrupt that occurs when the TONE IRQ FLAG (Bit 3, IRQ FLAG Register, $8F) changes from "0" to "1". When this bit is "0" the interrupt is masked. When this bit is set to "1" it enables an interrupt that occurs when the CTCSS FAST IRQ FLAG (Bit 2, IRQ FLAG Register, $8F) changes from "0" to "1". When this bit is "0" the interrupt is masked. When this bit is set to "1" it enables an interrupt that occurs when the DCS DECODE/NO DECODE FLAG (Bit 7, SELCALL & SUB-AUDIO STATUS Register $81) changes state. When this bit is set to "0" the interrupt is masked.
COMP 0 to 1 IRQ MASK (Bit 5) COMP 0 to 1 IRQ MASK (Bit 4) TONE IRQ MASK (Bit 3)
CTCSS FAST IRQ MASK (Bit 2) DCS IRQ MASK (Bit 0)
CTCSS TX/FAST RX FREQUENCY Register (Hex address $83) This is a 16-bit register. Byte (1) is sent first. When the CTCSS fast detector is enabled, the bits 0 to 12 define the receive frequency the fast predictive detector is looking for according to the formula below. When the CTCSS transmitter is enabled, the bits 0 to 12 control the frequency of the transmitted CTCSS tones according to the formula below. When the fast detector and the transmitter are both enabled, the bits 0 to 12 define the receive frequency the fast predictive detector is looking for and the frequency of the transmitted tone according to the formula below (i.e. Tx tone = predictive tone).
A=
fXTAL (Hz) 16 x fTONE (Hz)
where A is the binary number programmed into the 13 bits.
(c) 1997 Consumer Microcircuits Limited
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CTCSS/DCS/SELCALL Processor
FX828
When Bit 7 in byte (1) is set to "1" the tone output is set at VBIAS or NOTONE without regard to the number "A" programmed. When Bit 7 is "0" the programmed tone is set on the output. Programming the bits 0 to 12 to "0" puts the Tx into powersave and the output goes to VBIAS. Powersave is also achieved by disabling the SUBAUDIO Tx and the CTCSS FAST DETECT. RX TONE PROGRAM Register (Hex address $84) This is a 16-bit register. Byte (1) is sent first. The two bytes are used to program the centre frequencies of up to 15 tones in either the audio or sub-audio band that will be decoded by the receiver. Each tone is identified by its address in bits 7, 6, 5 and 4 of byte (1). The remaining 12 bits contain the data representing the tone frequency according to the formula below. If a tone is not required the 12 bits should be set to zero. Byte 1
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Bit 7 Bit 6 Bit 5
Byte 2
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 0 0 0 0 0 0 0 1 1 1 1 1 1 1
0 0 0 0 1 1 1 1 0 0 0 0 1 1 1
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
<------------------------ N -----------------------> N is the binary representation of the following decimal number (n):
<----------------------- R ------------------------> R is the nearest 6-bit binary representation of (r), where:
SUBAUDIO (CTCSS)
n = INT (948982 x fTONE / fXTAL)
SUBAUDIO (CTCSS)
r = ((237245/fXTAL) - (n/(4 x fTONE))) x 8400
INBAND (SELCALL)
n = INT (83036 x fTONE / fXTAL)
INBAND (SELCALL)
r = ((20759/fXTAL) - (n/(4 x fTONE))) x 96000
Example: To program 100Hz when using the recommended 4.032MHz Xtal in SUBAUDIO (CTCSS) mode. n= = N= r = = INT (948982 x 100 / 4.032 x 10^6) INT (23.536) = 23 010111 (binary) ((237245 / 4.032 x 10^6) - (23 / (4 x 100))) x 8400 11.26 (round up if exactly halfway) 11 001011 (binary)
R= =
Thus the 12-bit code is 010111001011 The Hex address represented by bits 7, 6, 5 and 4 in byte (1) is used as the code to indicate which tone has been decoded. This code appears in bits 3, 2, 1 and 0 of the SELCALL and SUB-AUDIO STATUS Register (Hex address $81). The 15 programmed tones use Hex addresses $0 - $E.
(c) 1997 Consumer Microcircuits Limited
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D/828/3
CTCSS/DCS/SELCALL Processor
FX828
AUDIO CONTROL Register (Hex address $8A) This is a 16-bit register. Byte (1) is sent first. Bits 0 - 5 of the first byte in this register are used to set the attenuation of the Modulator 1 amplifier and bits 0 - 5 of the second byte in this register are used to set the attenuation of the Modulator 2 amplifier, according to the tables below: BYTE 1
5 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 X 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 X 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 1 X 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 X 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Mod. 1 Attenuation Disabled (VBIAS) >40dB 12.0dB 11.6dB 11.2dB 10.8dB 10.4dB 10.0dB 9.6dB 9.2dB 8.8dB 8.4dB 8.0dB 7.6dB 7.2dB 6.8dB 6.4dB 6.0dB 5.6dB 5.2dB 4.8dB 4.4dB 4.0dB 3.6dB 3.2dB 2.8dB 2.4dB 2.0dB 1.6dB 1.2dB 0.8dB 0.4dB 0dB 5 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 X 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 X 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 2 X 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
BYTE 2
1 X 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 X 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Mod. 2 Attenuation Disabled (VBIAS) >40dB 6.0dB 5.8dB 5.6dB 5.4dB 5.2dB 5.0dB 4.8dB 4.6dB 4.4dB 4.2dB 4.0dB 3.8dB 3.6dB 3.4dB 3.2dB 3.0dB 2.8dB 2.6dB 2.4dB 2.2dB 2.0dB 1.8dB 1.6dB 1.4dB 1.2dB 1.0dB 0.8dB 0.6dB 0.4dB 0.2dB 0dB
X = don't care MOD1 ENABLE (Bit 5, first byte) MOD2 ENABLE (Bit 5, second byte) (Bits 7 and 6, first and second bytes) When this bit is "1" the MOD1 attenuator is enabled. When this bit is "0" the MOD1 attenuator is disabled (i.e. powersaved). When this bit is "1" the MOD2 attenuator and the SUMMING AMP are enabled. When this bit is "0" they are both disabled (i.e. powersaved). Reserved for future use. These should be set to "0".
SELCALL TX Register (Hex address $8D) This is a 16-bit register. Byte (1) is sent first. When the SELCALL transmitter is enabled, bits 0 to 12 control the frequency of the transmitted SELCALL tones according to the formula overleaf:
(c) 1997 Consumer Microcircuits Limited 15 D/828/3
CTCSS/DCS/SELCALL Processor
FX828
A=
fXTAL (Hz) 4 x fTONE (Hz)
where A is the binary number programmed into the 13 bits. When Bit 7 (in the first 8 bits) is set to "1" the tone output is set at VBIAS or NOTONE without regard to the number "A" programmed. When Bit 7 is "0" the programmed tone is set on the output. Programming the bits 0 to 12 to "0" puts the Tx into powersave and the output goes to VBIAS. Powersave is also achieved by disabling the SELCALL Tx. 8-bit Read Only Registers
HEX ADDRESS/ COMMAND REGISTER NAME SELCALL & $81 SUB-AUDIO STATUS BIT 7 (D7) DCS DECODE/ NO DECODE BIT 6 (D6) CTCSS FAST TONE GP TIMER $8F IRQ FLAG 0 IRQ FLAG COMP 0 to 1 IRQ FLAG 0 TONE DECODE COMP 1 to 0 IRQ FLAG MSB BIT 3 TONE IRQ FLAG BIT 2 CTCSS FAST IRQ FLAG 0 BIT 1 BIT 5 (D5) BIT 4 (D4) BIT 3 (D3) BIT 2 (D2) BIT 1 (D1) BIT 0 (D0)
RX TONE
LSB BIT 0 DCS IRQ FLAG
Read Only Register Description SELCALL and SUB-AUDIO STATUS Register (Hex address $81) This register is used to indicate the status of the device as described below: DCS DECODE/NO DECODE (Bit 7) CTCSS FAST TONE (Bit 6) When the DCS decoder is enabled this bit is continuously updated with the result. A "1" indicates a successful decode (with 3 or less errors). A "0" indicates a failure to decode. When Bit 5 in the SIGNALLING CONTROL Register and Bit 3 in the SIGNALLING SET-UP Register are set to enable FAST CTCSS DETECT mode, this bit will be set to "1" if a periodic tone is detected. If no periodic tone is detected this bit will be "0". When bits 5 and 3 are set to enable FAST CTCSS PREDICTIVE mode, this bit will be set to "1" if a periodic tone that matches the frequency programmed in the CTCSS TX/FAST RX FREQUENCY Register is detected. If no match is found this bit will be "0". When Bit 5 in the SIGNALLING CONTROL Register is set to "0" this bit will be "0". (Bit 5) Reserved for future use. This will be set to "0" but should be ignored by the user's software. This bit indicates the status of the tone decoder. A "1" indicates a tone has been detected (TONE DECODE) and a "0" indicates the loss of the tone (NOTONE).
TONE DECODE (Bit 4)
(c) 1997 Consumer Microcircuits Limited
16
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
TONE DECODE means that a tone has been decoded and its characteristics are defined by the bandwidth (See SIGNALLING SET-UP Register bits 7, 6, 5 and 4) and the RX TONE number (See SELCALL and SUB-AUDIO STATUS Register bits 3, 2, 1 and 0). When Bit 6 in the SIGNALLING CONTROL Register is set to "0" the TONE DECODE bit 4 will be set to "0". Identification of a valid tone which is not in the pre-programmed list of up to 15 tones will cause the decoder to move to the TONE DECODE state with the RX TONE address of "1111" in bits 3, 2, 1 and 0; indicating a valid, but unrecognised, tone. Loss of tone, will cause the NOTONE timer to be started. If loss of tone continues for the duration of the timeout period, then the decoder will move to NOTONE state and the identification of pre-programmed tones will start again. RX TONE (Bits 3, 2, 1 and 0) These four bits hold a Hex number from $0 to $F. Numbers $0 to $E represent the address of the tone decoded according to the tones programmed in the RX TONE PROGRAM Register, $84. The Hex number $F indicates the presence of any tone that is not described by DECODER BANDWIDTH (Bits 7, 6, 5 and 4, SIGNALLING SET-UP Register, $82) and FREQUENCY (Bits 11 - 0, RX TONE PROGRAM Register, $84).
IRQ FLAG Register (Hex address $8F) This register is used to indicate when the device requires attention as below: (Bits 7 and 1) Reserved for future use. These will be set to "0" but should be ignored by user's software. When the general purpose timer has reached zero in its internal register, this bit will be set to "1" to indicate the timeout has expired. This bit is cleared to "0" by a read of the IRQ FLAG Register (Hex address $8F). When the comparator output goes from "0" to "1" (i.e. when the input voltage is above the DAC output voltage) this bit will be set to "1" and an interrupt generated (if bit 5 of the IRQ MASK Register $8E is set to "1"). This bit is set to "0" when the IRQ FLAG Register $8F is read. When the comparator output goes from "1" to "0" this bit will be set to "1" and an interrupt generated (if bit 4 of the IRQ MASK Register $8E is set to "1"). This bit is set to "0" when the IRQ FLAG Register $8F is read. When RX TONE DECODE (Bit 4, SELCALL and SUB-AUDIO STATUS Register, $81) or Rx TONE (the decoded 4 bit tone address in Register $81) changes state this bit will be set to "1". This bit is cleared to "0" by a read of the IRQ FLAG Register (Hex address $8F). When CTCSS FAST TONE (Bit 6, SELCALL and SUB-AUDIO STATUS Register, $81) changes state this bit will be set to "1". This bit is cleared to "0" by a read of the IRQ FLAG Register (Hex address $8F). When DCS DECODE/NO DECODE (Bit 7 SELCALL and SUB-AUDIO STATUS Register, $81) changes state this bit will be set to "1". This bit is cleared to "0" by a read of the IRQ FLAG Register (Hex address $8F).
GPT IRQ FLAG (Bit 6)
COMP 0 to 1 IRQ FLAG (Bit 5)
COMP 1 to 0 IRQ FLAG (Bit 4) TONE IRQ FLAG (Bit 3)
CTCSS FAST IRQ FLAG (Bit 2) DCS IRQ FLAG (Bit 0)
(c) 1997 Consumer Microcircuits Limited
17
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
The flow chart shows the following modes of operation for the example below: 1. 2. 3. 4. Decode Decode and Fast Detect Decode & Fast Predictive Transmit, e.g. Tx = 100Hz ) ) e.g. Address 3 = 100Hz, bandwidth = 2.7%, interrupt enabled )
Note: $8X is the Hex address/command.
(c) 1997 Consumer Microcircuits Limited
18
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
The flow chart shows the decoder, fast detect/fast predictive and transmitter enabled with the following example. 1. 2. 3. 4. Tx tone generator = 100Hz Decoder programmed with 100Hz in address 3 Bandwidth setting = 2.7% Interrupt enabled
Note: $8X is the Hex address/command.
(c) 1997 Consumer Microcircuits Limited
19
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.6
Application Notes
1.6.1 General The FX828 is intended for use in radio systems where signalling is required for functions such as trunking, control, selective calling or group calling. The CTCSS fast/predictive detector is useful for the detection of occupied channels indicating either the presence of any sub-audio tone, or range of tones, depending if it is set in fast detect or predictive mode. This will increase the efficiency of scanning and trunking systems, reducing the average time allocated to assessing each channel. The facility to decode any of up to 15 programmed tones allows the use of tones for various signalling functions such as masking a free channel or identifying sub groups within a user's groups. Adjustable decoder bandwidths permit certainty and signal to noise performance to be traded when congestion or range limits the system performance. 1.6.2 Transmitters The CTCSS transmitter is enabled with Bit 7 in the SIGNALLING CONTROL Register ($80) and bit 1 in the SIGNALLING SET UP Register ($82). The Tx frequency is set using Bit 0 to Bit 12 in the CTCSS TX/FAST RX FREQUENCY Register ($83) using the formula below: fXTAL (Hz) A= 16 x fTONE (Hz) where A is the binary number programmed into the 13 bits. When Bit 7 (in the first 8 bits) is set to "1" the tone output is set at VBIAS or NOTONE without regard to the number "A" programmed. When Bit 7 is "0" the programmed tone is set on the output. Programming the bits 0 to 12 to "0" puts the Tx into powersave and the output goes to VBIAS. Powersave is also achieved by disabling the SUBAUDIO Tx and the CTCSS FAST DETECT (Bits 7 and 5 in the SIGNALLING CONTROL Register $80). The SELCALL transmitter is enabled with Bit 2 in the SIGNALLING CONTROL Register ($80). The Tx frequency is set using Bit 0 to Bit 12 in the SELCALL TX Register ($8D) using the formula below:
A=
fXTAL (Hz) 4 x fTONE (Hz)
where A is the binary number programmed into the 13 bits. When Bit 7 (in the first 8 bits) is set to "1" the tone output is set at VBIAS or NOTONE without regard to the number "A" programmed. When Bit 7 is "0" the programmed tone is set on the output. Programming the bits 0 to 12 to "0" puts the Selcall Tx into powersave and the output goes to VBIAS. Powersave is also achieved by disabling the SELCALL TX ENABLE (Bit 2 in the SIGNALLING CONTROL Register $80). The DCS transmitter is enabled with Bit 7 in the SIGNALLING CONTROL Register ($80) and bit 1 in the SIGNALLING SET UP Register ($82).
(c) 1997 Consumer Microcircuits Limited
20
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
The Tx data is set in the DCS BYTE 3, DCS BYTE 2 and DCS BYTE 1 Registers ($85, $86 and $87). Note that the DCS transmitter produces an inverted output. When the signal is fed through the summing amp, in an inverting configuration, the correct polarity of the DCS signal will be restored (the modulator gain blocks do not invert). 1.6.3 Receiver (CTCSS/Selcall Decoder) The CTCSS/Selcall decoder should first be set up according to the desired characteristics. This entails setting the TONE DECODER MODE Bit 2 of the SIGNALLING SET UP Register ($82), and setting the TONE decoder bandwidth in the SIGNALLING SET-UP Register ($82), also programming the centre frequencies of the desired tones in the RX TONE PROGRAM Register ($84). (It can hold up to 15 different tones). Any tone can be in any location. When the device is decoding, the tones are scanned in the sequence of their location, i.e. $0 first and $E last. Once a tone is detected the remaining tones are not checked. Therefore if two tones are close enough in frequency for their bandwidths to overlap then the one in the lowest location will be detected. The TONE IRQ MASK in the IRQ MASK Register ($8E) should also be set as required. The TONE DECODER ENABLE in the SIGNALLING CONTROL Register ($80) should then be set to "1". Whilst in the CTCSS/Selcall decoder mode the fast/predictive detector may be enabled (see below) (Bit 5 in the SIGNALLING CONTROL Register $80). When the CTCSS/Selcall decoder detects a change in its present state an IRQ will be generated and Bit 3 of the IRQ FLAG Register ($8F) will indicate this. The change that occurred can be read from Bit 4 of the SELCALL and SUB-AUDIO STATUS Register ($81) and if a tone is indicated by these bits then the number of that tone can be read from Bits 3, 2, 1 and 0 of the same register. 1.6.4 Receiver (CTCSS Fast/Predictive Detector) This is used for detecting, in the fastest possible time, that sub-audio tones are present on the Rx channel. Response time is optimised for speed at the expense of frequency resolution. It can operate in parallel to the CTCSS/Selcall decoder. It is enabled using Bit 5 of the SIGNALLING CONTROL Register ($80). It has an IRQ which may be unmasked with Bit 2 of the IRQ MASK Register ($8E). The FAST CTCSS MODE DETECT/PREDICTIVE Bit 3 in the SIGNALLING SET-UP Register ($82) allows for one of two alternatives in the FAST mode. In DETECT mode it will detect any periodic tone in the sub-audio band and when in PREDICTIVE mode it will detect specific tones determined by the frequency set in the CTCSS TX/FAST RX FREQUENCY Register ($83) and the fixed PREDICTIVE mode bandwidth. Successful detection is indicated by the CTCSS FAST IRQ FLAG Bit 2 in the IRQ FLAG Register ($8F), and the CTCSS FAST TONE Bit 6 in the SELCALL and SUB-AUDIO STATUS Register ($81). 1.6.5 Receiver (DCS Decoder) The incoming signal is matched with the DCS code programmed into the DCS BYTE 1/2/3 Registers. When the DCS decoder is enabled, the DCS DECODE/NO DECODE FLAG in Bit 7 of the SELCALL and SUB-AUDIO STATUS Register ($81) will be set if the decode is successful (3 or fewer errors). A ''0" flag indicates a failure to decode. This flag is updated for every bit of the incoming signal. In order to detect the DCS turn-off code (134Hz), the CTCSS Tone Decoder should also be enabled and programmed with this value. Once detected this will cause a CTCSS tone decode interrupt; the receiver audio output should then be muted.
(c) 1997 Consumer Microcircuits Limited
21
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.6.6 General Purpose Timer (GPT) This may be used in conjunction with the CTCSS/Selcall decoder to form part of the decode algorithm or as a timer for any other purpose. It has an 8-bit value in the GENERAL PURPOSE TIMER Register ($8B) set in units of 1msec, an IRQ FLAG in Bit 6 of the IRQ FLAG Register ($8F) and an IRQ MASK in Bit 6 of the IRQ MASK Register ($8E). 1.6.7 Full Duplex Modes The only functions that must operate as half duplex are: DCS Tx or DCS Rx DCS Tx or CTCSS Tx CTCSS decode or SELCALL decode All other functions are totally independent and therefore a full duplex CTCSS or full duplex SELCALL along with many other combinations are possible.
(c) 1997 Consumer Microcircuits Limited
22
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.6.8 Tx / Fast Rx Tone Table : CTCSS The following table lists the commonly used CTCSS tones and the corresponding values for programming the transmitter frequency / fast predictive frequency register (Hex address $83).
Freq. (Hz) 67.0 69.3 71.9 74.4 77.0 79.7 82.5 85.4 88.5 91.5 94.8 97.4 100.0 103.5 107.2 110.9
Byte 1 (hex) E E D D C C B B B A A A 9 9 9 8
Byte 2 (hex) B1 34 B1 3B C9 5A EF 87 1F C2 62 1B D8 83 2F E0
Freq. (Hz) 114.8 118.8 123.0 127.3 131.8 136.5 141.3 146.2 151.4 156.7 159.8 162.2 167.9 173.8 179.9 183.5
Byte 1 (hex) 8 8 8 7 7 7 6 6 6 6 6 6 5 5 5 5
Byte 2 (hex) 93 49 1 BC 78 36 F7 BC 80 48 29 12 DD AA 79 5D
Freq. (Hz) 186.2 189.9 192.8 196.6 199.5 203.5 206.5 210.7 218.1 225.7 229.1 233.6 241.8 250.3 254.1
Byte 1 (hex) 5 5 5 5 4 4 4 4 4 4 4 4 4 3 3
Byte 2 (hex) 49 2F 1B 2 EF D6 C4 AC 83 5D 4C 37 12 EF E0
1.6.9 Rx Tone Program Tables : CTCSS The following table lists the commonly used CTCSS tones together with the values for programming the "RX TONE PROGRAM" register (Hex address $84). N.B. The values for byte 1 and 2 below apply to tone address 0 only. These values will vary depending on the location they are programmed into. Freq. (Hz) 67.0 69.3 71.9 74.4 77.0 79.7 82.5 85.4 88.5 91.5 94.8 97.4 100.0 103.5 107.2 110.9 Byte 1 (hex) 3 4 4 4 4 4 4 5 5 5 5 5 5 6 6 6 Byte 2 (hex) D8 9 1B 4E 83 94 CB 2 14 4C 87 94 CB 7 45 82 Freq. (Hz) 114.8 118.8 123.0 127.3 131.8 136.5 141.3 146.2 151.4 156.7 159.8 162.2 167.9 173.8 179.9 183.5 Byte 1 (hex) 6 6 7 7 7 8 8 8 8 9 9 9 9 A A A Byte 2 (hex) C0 D1 10 50 C0 2 44 86 C9 C 48 82 C6 B 84 C2 Freq. (Hz) 186.2 189.9 192.8 196.6 199.5 203.5 206.5 210.7 218.1 225.7 229.1 233.6 241.8 250.3 254.1 Byte 1 (hex) A B B B B B C C C D D D E E E Byte 2 (hex) C9 8 44 83 8A C9 6 46 C3 41 48 89 8 88 C7
(c) 1997 Consumer Microcircuits Limited
23
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.6.10 Tx Tone Program Table : Selcall The following two tables list commonly used Selcall tonesets together with the values for programming the `SELCALL TX' register ($8D).
Freq. (Hz) 1981 1124 1197 1275 1358 1446 1540 1640 1747 1860 1055 930 2247 991 2110
EEA Byte 1 (hex) 01 03 03 03 02 02 02 02 02 02 03 04 01 03 01
Byte 2 (hex) FD 81 4A 17 E6 B9 8F 67 41 1E BB 3C C1 F9 DE
Freq. (Hz) 1981 1124 1197 1275 1358 1446 1540 1640 1747 1860 2400 930 2247 991 2110
CCIR Byte 1 (hex) 01 03 03 03 02 02 02 02 02 02 01 04 01 03 01
Byte 2 (hex) FD 81 4A 17 E6 B9 8F 67 41 1E A4 3C C1 F9 DE
Freq. (Hz) 2400 1060 1160 1270 1400 1530 1670 1830 2000 2200 2800 810 970 885 2600
ZVEI 1 Byte 1 (hex) 01 03 03 03 02 02 02 02 01 01 01 04 04 04 01
Byte 2 (hex) A4 B7 65 1A D0 93 5C 27 F8 CA 68 DC 0F 73 84
Freq. (Hz) 2400 1060 1160 1270 1400 1530 1670 1830 2000 2200 885 810 740 680 970
ZVEI 2 Byte 1 (hex) 01 03 03 03 02 02 02 02 01 01 04 04 04 05 04
Byte 2 (hex) A4 B7 65 1A D0 93 5C 27 F8 CA 73 DC 0F CA 0F
(c) 1997 Consumer Microcircuits Limited
24
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.6.11 Rx Tone Program Table : Selcall The following two tables list commonly used Selcall tonesets together with the values for programming the `RX TONE PROGRAM' register ($84) in each Tone Address location as shown.
Tone Address 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Freq. (Hz) 1981 1124 1197 1275 1358 1446 1540 1640 1747 1860 1055 930 2247 991 2110
EEA Byte 1 (hex) A 15 26 36 46 57 67 78 88 99 A5 B4 CB D5 EA
Byte 2 (hex) A C3 D 85 D1 4D CB 4B CD 84 51 C4 83 A C5
Freq. (Hz) 1981 1124 1197 1275 1358 1446 1540 1640 1747 1860 2400 930 2247 991 2110
CCIR Byte 1 (hex) A 15 26 36 46 57 67 78 88 99 AC B4 CB D5 EA
Byte 2 (hex) A C3 D 85 D1 4D CB 4B CD 84 44 C4 83 A C5
Tone Address 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Freq. (Hz) 2400 1060 1160 1270 1400 1530 1670 1830 2000 2200 2800 810 970 885 2600
ZVEI 1 Byte 1 (hex) C 15 25 36 47 57 68 79 8A 9B AE B4 C4 D4 ED
Byte 2 (hex) 44 53 D2 83 E C8 86 49 42 43 46 14 D8 86 45
Freq. (Hz) 2400 1060 1160 1270 1400 1530 1670 1830 2000 2200 885 810 740 680 970
ZVEI 2 Byte 1 (hex) C 15 25 36 47 57 68 79 8A 9B A4 B4 C3 D3 E4
Byte 2 (hex) 44 53 D2 83 E C8 86 49 42 43 86 14 C8 80 D8
(c) 1997 Consumer Microcircuits Limited
25
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.6.12 DCS Code Table The following table gives a list of DCS codes together with the corresponding values (in Hex) which should be programmed into the DCS BYTE registers for a 23-bit DCS sequence.
DCS Code 023 025 026 031 032 043 047 051 054 065 071 072 073 074 114 115 116 125 131 132 134 143 152 155 156 162 165 172 174 205 223 226 243 244 245 251 261 263 265 271 306 311
DCS Byte 3 ($85) 76 6B 65 51 5F 5B 0F 7C 6F 5D 67 69 2E 74 35 72 7C 07 3D 33 2E 37 1E 44 4A 6B 31 05 18 6E 68 7B 45 1F 58 62 17 5E 43 79 0C 38
DCS Byte 2 ($86) 38 78 D8 F8 58 68 D8 A8 48 18 98 38 68 78 E8 B8 18 B8 38 98 D8 A8 C8 D8 78 C8 D8 F8 B8 98 E8 08 B8 A8 F8 78 78 88 C8 48 F8 D8
DCS Byte 1 ($87) 13 15 16 19 1A 23 27 29 2C 35 39 3A 3B 3C 4C 4D 4E 55 59 5A 5C 63 6A 6D 6E 72 75 7A 7C 85 93 96 A3 A4 A5 A9 B1 B3 B5 B9 C6 C9
DCS Code 315 331 343 346 351 364 365 371 411 412 413 423 431 432 445 464 465 466 503 506 516 532 546 565 606 612 624 627 631 632 654 662 664 703 712 723 731 732 734 743 754
DCS Byte 3 ($85) 6C 23 29 3A 0E 68 2F 15 77 79 3E 4B 6C 62 7B 27 60 6E 3C 2F 41 0E 19 0C 5D 67 0F 01 72 7C 4C 24 39 22 0B 39 1E 10 0D 14 20
DCS Byte 2 ($86) 68 E8 78 98 B8 58 08 88 69 C9 99 99 59 F9 89 E9 B9 19 69 89 B9 39 E9 79 99 19 59 F9 89 29 39 79 39 B9 D9 89 49 E9 A9 D9 F9
DCS Byte 1 ($87) CD D9 E3 E6 E9 F4 F5 F9 09 0A 0B 13 19 1A 25 34 35 36 43 46 4E 5A 66 75 86 8A 94 97 99 9A AC B2 B4 C3 CA D3 D9 DA DC E3 EC
(c) 1997 Consumer Microcircuits Limited
26
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.7
1.7.1
Performance Specification
Electrical Performance
Absolute Maximum Ratings Exceeding these maximum ratings can result in damage to the device. Min. -0.3 -0.3 -30 -20 Max. 7.0 VDD + 0.3 +30 +20 Units V V mA mA
Supply (VDD - VSS) Voltage on any pin to VSS Current into or out of VDD and VSS pins Current into or out of any other pin
D2/P4 Package Total Allowable Power Dissipation at Tamb = 25C ... Derating Storage Temperature Operating Temperature
Min.
-55 -40
Max. 800 13 +125 +85
Units mW mW/C C C
D5 Package Total Allowable Power Dissipation at Tamb = 25C ... Derating Storage Temperature Operating Temperature
Min.
-55 -40
Max. 550 9 +125 +85
Units mW mW/C C C
Operating Limits Correct operation of the device outside these limits is not implied. Notes Supply (VDD - VSS) Operating Temperature Xtal Frequency Min. 3.0 -40 4.0315968 Max. 5.5 +85 4.0324032 Units V C MHz
(c) 1997 Consumer Microcircuits Limited
27
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
Operating Characteristics For the following conditions unless otherwise specified: Xtal Frequency = 4.032MHz Audio Level 0dB ref = 308mVrms at 1kHz VDD = 3.3V to 5.0V, Tamb = -40C to +85C. Composite Signal = 308mVrms at 1kHz + 75mVrms Noise + 31mVrms Sub-Audio Signal Noise Bandwidth = 5kHz Band Limited Gaussian Notes DC Parameters At VDD = 3.3V IDD (all powersaved) IDD (FAST DETECT Enabled) IDD (Rx Operating - DCS, FAST DETECT and CTCSS or Selcall) IDD (Tx Operating - DCS or Selcall or SUB AUDIO) IDD (Tx Operating - DCS and Selcall) At VDD = 5V IDD (all powersaved) IDD (FAST DETECT Enabled) IDD (Rx Operating - DCS, FAST DETECT and CTCSS or Selcall) IDD (Tx Operating - DCS or Selcall or SUB AUDIO) IDD (Tx Operating - DCS and Selcall) "C-BUS" Interface Input Logic "1" Input Logic "0" Input Leakage Current (Logic "1" or "0") Input Capacitance Output Logic "1" (IOH = 120A) Output Logic "0" (IOL = 360A) "Off" State Leakage Current (Vout = VDD) AC Parameters TONE Decoder Sensitivity CTCSS Response Time De-response Time Frequency Range SELCALL Response Time De-response Time Frequency Range DCS Decoder Bit-Rate Sync Time Sensitivity Min. Typ. Max. Units
2 2 2 2 2
-
0.5 1.7 3.0 1.5 2.5
1.0 2.5 4.5 3.0 4.0
mA mA mA mA mA
2 2 2 2 2
-
1.0 3.0 5.5 4.5 5.0
1.5 4.5 7.5 6.0 6.5
mA mA mA mA mA
6
70% -1.0 90% -
-
30% 1.0 7.5 10% 10
VDD VDD A pF VDD VDD A
(Pure Tone) (Composite Signal) (Composite Signal)
5
60 625
-26.0 140 145 14 22 -
253 3000
dB ms ms Hz ms ms Hz
(Good Signal) (Good Signal)
1
58
2 -
116
edges mVp-p
(c) 1997 Consumer Microcircuits Limited
28
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
Notes CTCSS Detector - Fast Detect Sensitivity (Pure CTCSS Tone) Response Time (Composite Signal) Frequency Range CTCSS Detector - Fast Predictive Sensitivity (Pure CTCSS Tone) Response Time (Composite Signal) Frequency Range Decode Bandwidth CTCSS Encoder Frequency Range Tone Frequency Resolution Tone Amplitude Tolerance Total Harmonic Distortion SELCALL Encoder Frequency Range Tone Frequency Resolution Tone Amplitude Tolerance Total Harmonic Distortion DCS Encoder Bit Rate Amplitude Tolerance Amplitude Audio Band-Pass Filter Passband Passband Gain (at 1.0kHz) Passband Ripple (w.r.t. gain at 1.0kHz) Stopband Attenuation Residual Hum and Noise Alias Frequency Output Impedances TX AUDIO OUT, TX SUB AUDIO OUT and RX AUDIO OUT
Min.
Typ.
Max.
Units
5
60.0
-26.0 56.0 -
253
dB ms Hz
5 7
60.0 -
-26.0 37.0 40.0
253 -
dB ms Hz Hz
1 9
60.0 -1.0 -
2.0
253 0.2 +1.0 -
Hz % dB %
1 9
208 -1.0 -
2.0
3000 0.2 +1.0 -
Hz % dB %
1 1
-1.0
134.4 871
+1.0
bits/s dB mVp-p
8 8 8 8
300 -2 33.0 -
0 -50.0 63
3000 +0.5 -
Hz dB dB dB dBp kHz
) Enabled ) Disabled
10
-
2.0 500
-
k k
Rx Amp and Summing Amp Open Loop Gain (I/P = 1mV at 100Hz) Unity Gain Bandwidth Input Impedance (at 100Hz) Output Impedance (Open Loop)
10 -
70.0 5.0 6.0
-
dB MHz M k
(c) 1997 Consumer Microcircuits Limited
29
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
Notes Transmitter Modulator Drives: Mod.1 Attenuator Attenuation (at 0dB) Cumulative Attenuation Error (wrt attenuation at 0dB) Output Impedance Input Impedance (at 100Hz) Mod.2 Attenuator Attenuation (at 0dB) Cumulative Attenuation Error (wrt attenuation at 0dB) Output Impedance General Purpose Timer Timing Period Range Count Interval Xtal/Clock Input Pulse Width ('High' or 'Low') Input Impedance (at 100Hz) Gain (I/P = 1mVrms at 100Hz) DAC Range Step Size Step Accuracy Input Impedance (COMPIN) Output Impedance (COMPOUT)
Min.
Typ.
Max.
Units
-0.2 -1.0 3 -
0 600 15.0
0.2 1.0 -
dB dB
k
-0.2 -0.6 3 -
0 600
0.2 0.6 -
dB dB
1 -
1
255 -
ms ms
4
40.0 10.0 20.0
-
-
ns M dB
1 1 1
312.5 -30.0 -
312.5 10 1
2500 +30.0 -
mV mV mV M k
Notes:
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
At VDD = 5.0V only. Signal levels or currents are proportional to VDD. Not including any current drawn from the device pins by external circuitry. Small signal impedance, at VDD = 5.0V and Tamb = 25C. Timing for an external input to the XTAL/CLOCK pin. With input gain components set as recommended in Figure 2. IRQN pin. From one tone to another tone. See filter response (Figure 3). Measured at MOD1 or MOD2 output. SUBAUDIO, SELCALL and DCS.
(c) 1997 Consumer Microcircuits Limited
30
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
10 0 -10 Gain (dB) -20 -30 -40 -50
300Hz 250Hz
-60 10 100
1000 Frequency (Hz)
3kHz
10000
100000
Figure 3 Audio Band-Pass Filter Frequency Response
Timing Diagrams
Figure 4 "C-BUS" Timing
(c) 1997 Consumer Microcircuits Limited
31
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
For the following conditions unless otherwise specified: Xtal Frequency = 4.032MHz, VDD = 3.3V to 5.0V, Tamb = -40C to +85C. Parameter tCSE tCSH tHIZ tCSOFF tNXT tCK "CS-Enable to Clock-High" Last "Clock-High to CS-High" "CS-High to Reply Output 3-state" "CS-High" Time between transactions "Inter-Byte" Time "Clock-Cycle" time Notes Min. 2.0 4.0 2.0 4.0 2.0 Typ. Max. 2.0 Units s s s s s s
Notes:
1. Depending on the command, 1 or 2 bytes of COMMAND DATA are transmitted to the peripheral MSB (Bit 7) first, LSB (Bit 0) last. REPLY DATA is read from the peripheral MSB (Bit 7) first, LSB (Bit 0) last. 2. Data is clocked into and out of the peripheral on the rising SERIAL CLOCK edge. 3. Loaded commands are acted upon at the end of each command. 4. To allow for differing Controller serial interface formats "C-BUS" compatible ICs are able to work with either polarity SERIAL CLOCK pulses.
(c) 1997 Consumer Microcircuits Limited
32
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.7.2
Packaging
Figure 5 Mechanical Outline: Order as part no. FX828D2
Figure 6 Mechanical Outline: Order as part no. FX828D5
(c) 1997 Consumer Microcircuits Limited
33
D/828/3
CTCSS/DCS/SELCALL Processor
FX828
1.7.2
Packaging (continued)
Figure 7 Mechanical Outline: Order as part no. FX828P4
Handling precautions: This product includes input protection, however, precautions should be taken to prevent device damage from electro-static discharge. CML does not assume any responsibility for the use of any circuitry described. No IPR or circuit patent licences are implied. CML reserves the right at any time without notice to change the said circuitry and this product specification. CML has a policy of testing every product shipped using calibrated test equipment to ensure compliance with this product specification. Specific testing of all circuit parameters is not necessarily performed.
CONSUMER MICROCIRCUITS LIMITED
1 WHEATON ROAD WITHAM - ESSEX CM8 3TD - ENGLAND Telephone: Telefax: e-mail: +44 1376 513833 +44 1376 518247 sales@cmlmicro.co.uk http://www.cmlmicro.co.uk
CML Microcircuits
COMMUNICATION SEMICONDUCTORS
CML Product Data
In the process of creating a more global image, the three standard product semiconductor companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc (USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA) Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML Microcircuits. These companies are all 100% owned operating companies of the CML Microsystems Plc Group and these changes are purely changes of name and do not change any underlying legal entities and hence will have no effect on any agreements or contacts currently in force. CML Microcircuits Product Prefix Codes Until the latter part of 1996, the differentiator between products manufactured and sold from MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX respectively. These products use the same silicon etc. and today still carry the same prefixes. In the latter part of 1996, both companies adopted the common prefix: CMX. This notification is relevant product information to which it is attached.
Company contact information is as below:
CML Microcircuits (UK)Ltd
COMMUNICATION SEMICONDUCTORS
CML Microcircuits (USA) Inc.
COMMUNICATION SEMICONDUCTORS
CML Microcircuits (Singapore)PteLtd
COMMUNICATION SEMICONDUCTORS
Oval Park, Langford, Maldon, Essex, CM9 6WG, England Tel: +44 (0)1621 875500 Fax: +44 (0)1621 875600 uk.sales@cmlmicro.com www.cmlmicro.com
4800 Bethania Station Road, Winston-Salem, NC 27105, USA Tel: +1 336 744 5050, 0800 638 5577 Fax: +1 336 744 5054 us.sales@cmlmicro.com www.cmlmicro.com
No 2 Kallang Pudding Road, 09-05/ 06 Mactech Industrial Building, Singapore 349307 Tel: +65 7450426 Fax: +65 7452917 sg.sales@cmlmicro.com www.cmlmicro.com
D/CML (D)/1 February 2002

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