Port Allocations - Icom IC-M504 Service Manual

4-6 PORT ALLOCATIONS

4-6-1 CPU (LOGIC UNIT; IC1)
Pin Port
No. Name
Outputs DSC encode signal to the LPF (AF
1 DSENC
UNIT; IC8, pin 3).
Outputs beep sounds to the AF power amplifi er
2 BEEP
(IC9, pin 1).
Outputs PLL strobe signal to the PLL IC (MAIN
3 PSTB
UNIT; IC1, pin 3).
Outputs strobe signal to the expand IC's (AF
4 EXTSTB
UNIT; IC27/IC28, pin 1).
Outputs strobe signal to the attached optional
5 OPSTB scrambler unit via the option connector (AF
UNIT; J3, pin 6).
Inputs decoded ATIS/DSC signals from the DSC
16 DSDM
decoder (AF UNIT; IC11, pin 7).
Inputs decoded DSC signals from the DSC
17 DSD70
decoder (AF UNIT; IC15, pin 7).
Input port for the [PWR] key.
18 PWR
"Low"=When the key is pushed.
Outputs fog horn signal mute signal to the fog
21 FOGC
horn mute switch (AF UNIT; IC4).
Outputs fog horn sound to the fog horn mute
22 FOG
switch (AF UNIT; IC4).
Outputs control signal to the power controller
23 PWRON
(AF UNIT; Q61, Q62).
Outputs T5 line control signal to the T5V
24 SEND
controller (MAIN UNIT; Q52, Q57).
Outputs R10V line control signal to the R10V
25 RCV
regulater (MAIN UNIT; Q54, Q55).
NMTXD,
29−30 Data I/O ports for NMEA data.
NMRXD
Data I/O port for EEPROM (LOGIC BOARD;
35 EDATA
IC3, pin 5).
Outputs clock signal to the EEPROM (LOGIC
36 ECK
BOARD; IC3, pin 6).
Outputs OE signal to the expanders (AF UNIT;
38 EXTOE
IC27/28, pin 15).
Input to port for hang up detect signal from HM-
40 HANG
126B/G.
Input port for the [PTT] switch of HM-126B/G.
41 PTT
"Low"=When the switch is pushed.
Outputs serial data to the electric volume IC (AF
42 EVDATA
UNIT; IC13, pin 4)
Outputs clock signal to the electric volume IC
43 EVCK
(AF UNIT; IC13, pin 5).
Input port for the [DISTRESS] key (LOGIC
45 DTRS UNIT; S10).
"Low"=When the key is pushed.
Input port for the [MENU] key (LOGIC UNIT; S9).
46 MENU
"Low"=When the key is pushed.
Input port for the [CLR] key (LOGIC UNIT; S8).
47 CLR
"Low"=When the key is pushed.
Input port for the [HAIL] key (LOGIC UNIT; S7).
48 HAIL
"Low"=When the key is pushed.
Input port for the [LO/DX] key (LOGIC UNIT; S6).
49 LO/DX
"Low"=When the key is pushed.
Input port for the [CH16] key (LOGIC UNIT; S5).
50 CH16
"Low"=When the key is pushed.
Input port for the [ENTER] key.
51 ENT
"Low"=When the key is pushed.
Input port for the [CH/WX] key (LOGIC UNIT; S4).
52 CH/WX
"Low"=When the key is pushed.
Input port for the [SCAN] key (LOGIC UNIT; S3).
53 SCAN
"Low"=When the key is pushed.
Outputs transmit power select signal to the TX
54 H/L power controller (MAIN UNIT; Q17).
"High"=25 W, "Low"=1 W
Description
Pin Port
No. Name
Input port for PLL unlock signal from the PLL IC
58 UNLK (MAIN UNIT; IC1, pin 7).
"High"=While the PLL is unlocked.
Input port for optional unit attachement
detect signal VIA J3 pin 5 (AF UNIT).
59 OPTIN
"Low"=While the optional scrambler unit is
attached.
72, DIALA,
Input port for [DIAL] (DIAL BOARD; DS1).
73 DIALB
Input port for squelch adjustment VR (SQL
88 SQLV
BOARD; R1).
Input port for low power supply voltage detect
89 LBAT
signal.
Input port for transmit output power level from the
90 TXDET
power detector (MAIN UNIT; D12, D13).
Input port for noise signal from the FM IF IC
91 SQL
(MAIN UNIT; IC2, pin 14).
Input port for decoded weather alert signal from
92 WXDEC
the FM IF IC (IC2, pin 9) via LPF (Q38).
Outputs serial data to the PLL IC (MAIN UNIT;
99 PDATA
IC1, pin 5).
Outputs clock signal to the PLL IC (MAIN UNIT;
100 PCK
IC1, pin 4).
4-6-2 EXPAND IC (AF UNIT; IC27)
Pin Port
No. Name
Outputs transmit mute signal to the TX mute
5 TMUTE switch (MAIN UNIT; Q16).
"High"=During mute.
Outputs attenuator control signal to the
6 ATT attenuator (MAIN UNIT; D22).
"High"=During attenuator ON.
Outputs AF mute signal to the AF mute switch
7 RMUTEM (IC4, pin 6).
"Low"=During mute.
Outputs hailer mute signal to the hailer amplifi er
11 HAMUTE controller (Q66).
"Low"=During mute.
Outputs speaker mute signal to the AF mute
12 SPMUTE switch (Q65).
"High"=During mute.
Outputs hailer mute signal to the AF mute switch (Q66).
13 RMUTEH
"Low"=During mute.
4-6-3 EXPAND IC (AF UNIT; IC28)
Pin Port
No. Name
Outputs MIC mute signal (for intercom) to AF
4 MMUTEM mute switch (IC5).
"Low"=During mute.
Outputs MIC mute signal (for hailer) to AF mute
6 MMUTEH switch (IC5).
"Low"=During mute.
Outputs MIC mute signal (for HM-126B/G) to AF
7 PTTM mute switch (IC5).
"Low"=During mute.
Outputs the attached scrambler control signal via J3.
11 SCON
"High"=When the scrambler is activated.
Outputs scrambler by-pass (MIC signals) signal
to the AF mute switch (IC4).
12 SCUSE "High"=When the attached scrambler is activated.
"Low"=When the optional scrambler unit is not
Outputs scrambler by-pass (demodulated sig-
nals) signal to the AF mute switch (IC4).
13 SCPASS
"High"=When the attached scrambler unit is not
4 - 5
Description
Description
Description
attached.
activated or not attached.