4 - 5
Outputs dimmer control signal.
High: Dimmer is ON.
Outputs backlight control signal.
High: Backlight is ON.
Output LCD segment signals.
Output LCD common signals.
I/O ports for the optional board control
signals.
Input port for the clock signal from the
optional board via J1.
Input port for the cloning signal.
Output port for the cloning signal.
Input port for the POWER switch.
• Input port for the remote power con-
trol signal from the external connector
(J6).
• Input port for the dimmer control.
Input port for the “NOIS” signal from
the FM IF IC (MAIN unit; IC1) for noise
squelch operation.
Input port for interruption signal from
the optional board via J1.
Outputs chip select signal for the
optional board via J1.
Input port for the PTT switch from
microphone.
Input port for the PTT switch from the
external connector (J6).
Low : External PTT switch is ON.
Input port for the microphone hanger
detection signal.
Low : Microphone on hook.
Input port for the AF volume control
signal (R14).
High : [VOL] is maximum clockwise.
Input port for the CTCSS/DTCS decod-
ing signals.
Input port for the single tone decoding
signal.
Input port for the optional board detec-
tion signal.
Input port for receiving signal strength
level detection.
Input port for the PLL lock voltage.
44–46
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
OPT3–
OPT1
SI
CLI
CLO
POSW
DIM
NOIS
CIRQ
CCS
PTT
EPTT
HANG
AFVI
CDEC
SDEC
OV12
RSSI
LVIN
Pin
Port
Description
number
name
Outputs transmit/receive control signal.
High: While receiving.
Outputs audio output control signal.
High: While receiving.
Outputs wide/narrow control signal.
High: Wide is selected.
Outputs receiving mute control signal.
Low: While receiving is muting.
Outputs busy detecting signal to the
optional unit.
Outputs transmitting mute control sig-
nal.
Low: While transmitting is muting.
Outputs the microphone mute control
signal.
Low: While the microphone is muting.
4
5
6
7
11
13
14
RXC
AFON
NWC
RMUT
BUSY
TMUT
MMUT
Pin
Port
Description
number
name
1
2
3–34
35–38
LIGT1
LIGT2
SEG32–
SEG1
COM4–
COM1
Pin
Port
Description
number
name
4-5-3 LCD DRIVER (FRONT UNIT; IC6)
4-5-2 OUTPUT EXPANDER (MAIN UNIT; IC17)
CPU-Continued
Outputs the detection level control sig-
nal for the squelch circuit.
Outputs the TENC level control signal.
Outputs the modulation balance con-
trol signal.
Outputs the tuning voltage for band-
pass filters
• Outputs the tuning voltage for band-
pass filters.
• Outputs transmitting power control
signal.
Outputs the reference oscillator cor-
recting voltage.
2
4
11
14
22
23
SQIN
TENC
BAL
T1
T2
REF
Pin
Port
Description
number
name
4-5-4 D/A CONVERTER IC (MAIN UNIT; IC6)
