Port Allocations - Icom IC-M401EURO Service Manual

4-7 PORT ALLOCATIONS

4-7-1 CPU (LOGIC BOARD; IC1)
Pin Port
number name
Outputs control signal for the LCD
contrast.
1 CONT1
CONT1
2 CONT2
3 BEEPM Outputs beep audio signal.
Input port for the CH16 switch.
5 CH16
Low: While CH16 switch is pushed.
Input port for the CH switch.
6 CH
Low: While CH switch is pushed.
Input port for the H/L switch.
7 H/L
Low: While H/L switch is pushed.
Input port for the MIC hanging signal.
8 HANG
Low: While MIC is pull-up.
Outputs clock signal to the PLL IC
16 PCK
(MAIN unit; IC2, pin 4).
Outputs strobe signals to the PLL IC
17 PSTB
(MAIN unit; IC2, pin 3).
Outputs data signals to the PLL IC
18 PDATA
(MAIN unit; IC2, pin 5).
Outputs control signal to swtich NMEA
20 ICFC
or ICF3.
Outputs beep volume control signal.
21 BPLVL
Low: Beep audio is maximum.
Outputs clock signal for the EEPROM
22 ECK
(IC2, pin 6).
23 EDA I/O port for the EEPROM data signals.
Output port for RF output power (High
27 HI/LO
or Low) select signal.
28 RRXD Input port for the cloning data.
29 RTXD Output port for cloning data.
Outputs bandpass filter select signals.
31 BPFV Low: Receiving more than 160 MHz.
High: Receiving less than 160 MHz.
Outputs transmit mute signal.
83 TMUT
High: While transmitting.
84 NMEAI Input port for DS-100 data.
85 NMEAO Outputs cloning data signal.
Input port for the squelch volume
89 SQLV
level.
Input port from the FM IF IC (MAIN
90 SQL
unit; IC1) for the squelch operation.
Input port for the connected power
91 LBAT supply voltage detection (low battery
indicator).
92 TXDET Input port for TX LED control signal.
Description
CONT2
CONTRAST
0
LIGHT
0
1 DEEP
1
Pin Port
number name
93 KEYM
94 PTT
95 TAG
96 SCN
97 UP
98 DN
99 UNLK
4-7-2 I/O EXPANDER IC (LOGIC BOARD; IC3)
Pin Port
number name
4 RMUTM
6 PTTM
13 SEND
14 RCV
4 - 5
Description
Input port for the HM-132 functions.
2.02 V: [UP] is pushed.
3.00 V: [DN]] is pushed.
3.84 V: [16/C] is pushed.
Input port for the PTT switch from HM-
132.
Low: While PTT is pushed.
Input port for the TAG switch.
Low: While TAG switch is pushed.
Input port for the SCN switch.
Low: While SCN switch is pushed.
Input port for the UP switch.
Low: While UP switch is pushed.
Input port for the DOWN switch.
Low: While DOWN switch is pushed.
Input port for the PLL unlock signal.
Low: While PLL is locked.
Description
Outputs the AF mute swtich (MAIN
unit; IC5) control signal for main body.
Low: While squelched
Outputs main microphone (HM-132)
select signal to the analog swtich
(IC4) while intercom operation.
Outputs the T5 regulator (MAIN unit;
Q24, Q25) control signal.
High: While transmitting
Outputs the R5 regulator (MAIN unit;
Q22, Q23) control signal.
High: While receiving.