Port Allocations - Icom IC-M304 Service Manual

4-7 CPU PORT ALLOCATIONS
Pin
Port name
NO.
Input port for keys on HM-150B/SW.
Approx. 2.02 V: [Y] key is pushed.
2 KEYM
Approx. 3.00 V: [Z] key is pushed.
Approx. 3.84 V: [H/L] key is pushed.
3 TXDET Input port for transmit detected voltage.
4 LBAT Input port for low battery detecting.
Input port for "NOISE" signal from the squelch
5 SQL
amplifi er (IC11, pin 4).
Input port for squelch adjustment pot (SQL
6 SQLV
BOARD; R1).
Input port for weather alert signal from the
7 WXDEC
LPF (Q38).
8 PDATA Outputs data signal to the PLL IC (IC1, pin 5).
9 PCK Outputs clock signal to the PLL IC (IC1, pin 4).
10 PSTB Outputs strobe signal to the PLL IC (IC1, pin3).
Outputs volume control signal to the volume
12 EVDATA
ccontroller (IC13, pin 5) for PA circuit.
Outputs clock signal to the volume ccontroller
13 EVCK
(IC13, pin 4) for PA circuit.
Input port for the DSC decode signal from the
14 DSDEC
DSC decoder (IC15, pin 7).
28, CONT1, Output LCD contrast adjust signal to the CPU
29 CONT0 (IC1, pin 134).
Outputs serial data signal to the connected
32 COMTXD
HM-157 (Optional product).
Input port for the serial data signal from the
33 COMRXD
connected HM-157 (Optional product).
Outputs clock signal to the EEPROM (LOGIC
34 ECK
BOARD; IC4, pin 6).
I/O port for the EEPROM (LOGIC BOARD;
35 EDATA
IC4, pin 5) control data.
37 NMTXD Outputs NMEA command signal.
38 NMRXD Input port for the NMEA signal.
Input port for power switch (VR BOARD; R1).
48 PWR
Low: When [VOL] is pushed.
Outputs control signal to the AF (Public Ad-
49 PAMUTE dress) mute circuit (Q65).
High: During mute.
Outputs power control signal to the power
50 PWRON control circuit (Q61, Q62).
High: While the transceiver is switched ON.
Outputs transmit mute signal to the APC circuit
51 TMUTE (IC12, pin 3).
High: During mute.
Outputs control signal to the R5 control circuit
53 RCV (Q53, Q54).
High: While receiving.
Outputs TX power control signal to the TX
power control circuit (Q17, D11).
54 H/L
High: 25 W
Low: 1 W
Outputs attenuator control signal to the
55 ATT attenuator (D22).
High: Attenuator ON.
Input port for the [PTT] switch (HM-150B/SW; S1).
57 PTT
Low: [PTT] key is pushed.
Input port for the "UNLK" signal from the PLL
60 UNLK IC (IC1, pin7).
High: PLL circuit is unlocked.
Description
Pin
Port name
NO.
Input port for the [DISTRESS] key (LOGIC
61 DTRS BOARD; S9).
Outputs AF (Public Address) mute signal to
62 RMUTEP the AF mute circuit (IC4, pin12).
Outputs AF mute signal to the AF mute circuit
(IC4, pin 5) for the connected HM-157 (Op-
63 RMUTES
tional product).
Outputs AF (internal speaker) mute signal to the
64 RMUTEM AF mute circuit (IC4, pin 6).
Outputs microphone (Public Address) mute
65 MMUTEP signal to the AF mute circuit (IC5, pin 6).
Outputs microphone mute signal to the AF
mute circuit (IC5, pin 5) for the connected
66 MMUTES
HM-157 (Optional product).
Outputs microphone (HM-150B/SW) mute sig-
67 MMUTEM nal to the AF mute circuit (IC5, pin 13).
Outputs AF/MIC control signal to the AF mute
68 PTTS circuit (IC6, pin 5).
Outputs AF/MIC control signal to the AF mute
69 PTTM
circuit (IC5, pin 12).
Input por t for the [LO/DX] key (LOGIC
70 LO/DX BOARD; S8).
Input port for the [DSC] key (LOGIC BOARD; S7).
71 DSC
Input port for the [PA] key (LOGIC BOARD; S6).
72 PA
Input por t for the [CH/WX] key (LOGIC
73 CH/WX BOARD; S5).
Input port for the [SCAN] key (LOGIC BOARD; S4).
74 SCAN
Input port for the [16] key (LOGIC BOARD; S3).
75 CH16
Input port for the [Z] key (LOGIC BOARD; S2).
76 DOWN
Input port for the [Y] key (LOGIC BOARD; S1).
77 UP
Outputs dimmer control signal to the LCD control
138 DIM
circuit (LOGIC BOARD; Q2, Q3).
139 BEEP Outputs beep signal to the AF amplifi er (IC9, pin 1).
• While transmitting:
Outputs DSC encode signal as "DSENC"
to the LPF (IC8, pin 5) via the buffer amplifi er
(LOGIC BOARD; IC5, pins 1, 3).
141 DS/BPF
• While receiving:
Outputs tuning signal as "BPFV" to the
tunable BPFs (D25–D28) via buffer amplifi er
(LOGIC BOARD; IC5, pins 5, 7).
4 - 5
Description
Low: [DISTRESS] key is pushed.
Low: During mute.
Low: During mute.
Low: During mute.
Low: During mute.
Low: During mute.
Low: During mute.
High: PTT switch (HM-157) is pushed
Low: [LO/DX] key is pushed.
Low: [DSC] key is pushed.
Low: [PA] key is pushed.
Low: [CH/WX] key is pushed.
Low: [SCAN] key is pushed.
Low: [16] key is pushed.
Low: [Z] key is pushed.
Low: [Y] key is pushed.