Icom IC-A110 Service Manual page 11

3-5-2 CPU (FRONT unit; IC1)
Pin Port
number name
1, 2, 3,
KR4 Input ports for the key matrix.
5, 8, 12
9 RESET Input port for the CPU reset signal.
Outputs control signal for the power
10 PSWC supply circuit.
High: Power is ON.
11 BEEP Outputs beep audio signals.
Outputs clock signal to the EEPROM
13 ECK
(FRONT unit; IC4, pin 6).
Outputs data signal to the EEPROM
14 ESO
(FRONT unit; IC4, pin 5).
Outputs chip select signal to the EEP-
15 ECS
ROM (FRONT unit; IC4, pin 1).
16, DLA,
Input port for the [DIAL] control signal.
17 DLB
Outputs control signal to the expander
18 OE
IC (FRONT unit; IC5, pin 15).
Outputs
19 EXSTB
expander IC (FRONT unit; IC5, pin 1).
Outputs chip select signal to the elec-
20 VCS tric volume (MAIN unit; IC13).
Low: While volume is controlled.
Outputs serial clock to the PLL IC
(MAIN unit; IC2, pin 3), the expander
21 SCK IC (FRONT unit; IC5, pin 3) and the
electric volume (MAIN unit; IC13, pin
8).
Input port for the data signal from the
22 ESI
EEPROM (FRONT unit; IC4, pin 2).
Outputs serial data to the PLL IC
(MAIN unit; IC2, pin 4), the expander
23 SO IC (FRONT unit; IC5, pin 2) and the
electric volume (MAIN unit; IC13, pin
9).
Outputs strobe signals to the PLL IC
24 PLSTB
(MAIN unit; IC2, pin 5).
Outputs 2nd IF filter's select signal.
25 FISW
High: While wide is selected.
Input port for the unlock signal from
69 UNLK the PLL IC (MAIN unit; IC2, pin 11).
Low: PLL is unlocked.
70 CLIN Input port for the cloning signal.
71 CLO Output port for the cloning signal.
Input port for the POWER switch.
72 PSW Low: While
74 SQLI Input port for the squelch signal.
Description
strobe signals to
POWER switch
pushed
Pin Port
number name
76 HANG
77 PTT
78–80 KR1–KR2
the
is
3 - 6
Description
Input port for the microphone hanger
detection signal.
Low: Microphone on hook.
Input port for the PTT switch.
High: While PTT switch is pushed.
Input ports for the key matrix.