Port Allocations - Icom IC-M45 Service Manual

3-5 PORT ALLOCATIONS

3-5-1 CPU (LOGIC unit; IC1)
Pin Port
number name
Input port for the connected power
3 LBATT supply voltage detection (low voltage
indicator).
5 PTT.M Input port for the PTT switch.
Input port for the "TX" indicator from
6 TXDET the power detector circuit (Main unit;
D11, D12).
7 SQLV Input port for the squelch volume level.
Input port for the smart mic functions.
2.02 V: [UP] is pushed
8 KEY.M
3.00 V: [DN] is pushed
3.84 V: [HI/LO] is pushed
10 BEEP Outputs beep audio signals.
Outputs strobe signals for the output
13 OEX.STB
expander (MAIN unit; IC7).
Outputs strobe signals for the PLL cir-
14 P.STB
cuit.
Outputs data signals to the EEPROM
15 DATA (IC4), PLL IC (MAIN unit; IC3) and
expander ICs (MAIN unit; IC7), etc.
Outputs clock signal to the EEPROM
16 CK (IC4), PLL IC (MAIN unit; IC3) and
expander ICs (MAIN unit; IC7), etc.
Input port for the data signals from the
17 ESI
EEPROM (IC4).
Input port from the FM IF IC (MAIN
22 SQL
unit; IC1) for the squelch operation.
Input port for the PLL unlock signal.
23 UNLK
Low : While PLL is locked.
Input port for the weather alert tone
decode signal.
24 TONE
Low : Weather alert tone (1050 Hz)
LAMP2, Outputs LCD backlight control signal.
26, 27
LAMP1 High : While LCD backlight is ON.
Input port for the microphone hanger
31 HANG detection signal.
Low : Microphone on hook
33 DOWN Input port for the [DOWN] switch.
34 UP Input port for the [UP] switch.
35 H/L Input port for the [H/L] switch.
Input port for the [SCAN] switch.
36 SCAN
37 CH/WX Input port for the [CH/WX] switch.
38 CH16/9 Input port for the [16/9] switch.
Description
is detected.
3-5-2 OUTPUT EXPANDER (MAIN unit; IC7)
Pin Port
number name
4 RCV
5 SEND
11 HI/LO
12
OP.RST
13 RMUT
14 TMUT
3 - 4
Description
Outputs the R5 regulator (Q19, Q20)
control signal.
Low : While receiving
Outputs the T5 regulator (Q17, Q18)
control signal.
Low : While transmitting
Output port fo RF output power (High
or Low) select signal.
Low : While low power is selected
Outputs the reset signal for optional
unit via J5 (MAIN unit).
Outputs the analog switch (IC5) con-
trol signal.
Low : While squelched
Outputs transmit mute signal.
Low : While transmitting