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