Icom IC-M424 Service Manual page 14

4-5 PORT ALLOCATIONS
• CPU (LOGIC UNIT: IC1)
PIN LINE
No. NAME
[Y] key input.
10 UP
L=Pushed.
[Z] key input.
11 DN
L=Pushed.
[ ] key input.
12 LEFT
L=Pushed.
[ ] key input.
13 RIGHT
L=Pushed.
[ENT] key input.
14 ENT
L=Pushed.
[CLEAR] key input.
15 CLR
L=Pushed.
[MENU] key input.
18 MENU
L=Pushed.
[16/C] key input.
19 CH16
L=Pushed.
[DISTRESS] key input.
20 DIST
L=Pushed.
Soft key (LOGIC UNIT: S1*) input.
21 S1
L=Pushed.
Soft key (LOGIC UNIT: S2*) input.
22 S2
L=Pushed.
26 TEMPV Temperature sensing voltage.
27 TDETV Transmit output power sensing voltage.
28 LOINV Lock voltage input.
29 WDECV Weather alert signal detect.
Power switch input.
34 POW
L=Pushed.
40 DSCOUT DSC signal encoding output.
41 BEEP Beep audio. (Square waves)
43 KEYV [Y] and [Z] (HM-196) key input.
44 NOISEV Noise level detect.
46 LBAT Power supply voltage.
Soft key (LOGIC UNIT: S3*) input.
49 S3
L=Pushed.
Soft key (LOGIC UNIT: S4*) input.
50 S4
L=Pushed.
[PTT] (HM-196) input.
53 PTTIN
L=Pushed.
56 DB0
LCD driver control signal.
57 DB1
58 SDATA Common serial data.
59 SCK Common serial clock.
D/A converter (MAIN UNIT: IC514)
63 DASTB
strobe.
64 PLSTB PLL (MAIN UNIT: IC101) strobe.
Expander (MAIN UNIT: IC801 and
65 IOSTB
IC802) strobe.
Serial data to the COMMANDMI-
69 COM1TXD
CIV™.
Serial data from the COMMANDMI-
70 COM1RXD
CIV™.
RX AF mute switch (MAIN UNIT:
IC504) control. (For COMMANDMI-
77 REXTM
CIV™)
L=AF mute.
RX AF mute switch (MAIN UNIT:
78 RXSPM IC504) control. (For HM-196)
L=AF mute.
DESCRIPTION
PIN LINE
I/O
No. NAME
87–
DB2–DB7
I
92
93 WR0
I
96 DIALA
I
97 DIALB
I
101 NM1TXD
I
102 NM1RXD NMEA input.
103 DSCIN
I
113 CLOTXD
114 DTEST
I
116 CLORXD
I
117 PON
I
125 CS
I
126 RESETB
I
135 UNLKI
I
I
136 DIMM
I
141 ECK
I
I
142 EDATA
O
*; Soft key location
O
I
I
I
I
I
I
I/O
I
I
• D/A CONVERTER (MAIN UNIT: IC514)
I PIN LINE
No. NAME
I
2 AFVOLO
I 3 FCON
11 SQL
O
14 MSENS
15 PCON
I
23 PAVOLO
O
O
4 - 5
DESCRIPTION
LCD driver (LOGIC UNIT: DS1) con-
trol signal.
LCD driver (LOGIC UNIT: DS1) write
mode switch.
Rotary encoder pulse input (phase-
A).
Rotary encoder pulse input (phase-
B).
NMEA output.
Decoded DSC signal input.
Cloning data.
DSC loop back testing signal.
Cloning data.
Power supply line VCC control.
L=While transceiver's power is ON.
LCD driver (LOGIC UNIT: DS1) chip
select.
LCD driver (LOGIC UNIT: DS1) re-
set signal.
L=The LCD driver is reset.
PLL unlock detect.
L=Unlocked.
LCD brightness control.
EEPROM (LOGIC UNIT: IC9) serial
clock.
EEPROM (LOGIC UNIT: IC9) serial
data.
S1 S2 S3 S4
DESCRIPTION
AF output level adjustment. (RX signal)
Reference frequency adjustment.
Noise squelch level adjustment.
MIC sensitivity adjustment.
TX output power adjustment.
AF output level adjustment. (Public ad-
dress signal)
I/O
O
O
I
I
O
I
I
O
O
I
O
O
O
I
O
O
I/O