Port Allocations - Icom IC-A24 Service Manual

4-5 PORT ALLOCATIONS

4-5-1 CPU (LOGIC unit; IC1)
Pin Port
number name
Outputs control signal for the 5 V
1 PCON
regulator (IC16, Q4, Q6, Q7, D10).
2 VORS Input port for the 30 Hz phase signal.
Input port for the VOR 30 Hz standard
3 VORC
signal.
Outputs the bias control signal for a
4 BPCPI
type of battery.
5 LIGHT Input port for [LIGHT] switch.
6 CLIN Input port for the cloning signal.
7 CLOUT Outputs the cloning signal.
I/O port for data signal from/to the
10 EDATA
EEPROM (LOGIC unit; IC7)
Outputs clock signal to the EEPROM
11 ECK
IC (LOGIC unit; IC7).
12 POWER Input port for [POWER] switch.
Input port for [PTT] switch.
13 PTT High: W h i l e [ P T T ] s w i t c h i s
Input port for the PLL unlock signal.
14 UNLK
Low: PLL is unlocked.
Input port for the external DC connec-
17 DCC
tion detection.
25 RESET Input port for the CPU reset signal.
Input port for the VOR signal detec-
28 VORD
tion.
29 RSSI Input port for the receive signal level.
Input port for the power detection of
30 RFDETV
power amplifi er (RF unit; Q2).
Input port for the transceiver's internal
31 THRMC
temperature.
Input port for the battery type detec-
32 SBATT
tion.
Input port for the battery voltage de-
34 VIN
tection.
38 BEEP Outputs BEEP audio signals.
Outputs strobe signal to the PLL IC
109 PSTB
(RF unit; IC3).
Outputs data signals to the PLL IC (RF
110 PDATA
unit; IC3).
Outputs clock signal to the PLL IC (RF
111 PCK
unit; IC3).
Outputs control signal to the T5 regu-
112 TXC
lator circuit (Q7, Q8, D8).
Input port for external SP jack con-
nection detection.
115 JACKDET
High: While external SP jack is
DICK,
119, 120 Input ports for [DIAL].
DIUD
Description
pushed.
connected.
4-5-2 EXPANDER (RF unit; IC5)
Pin Port
number name
4 AFC
5 ALCC
6 R5C
7 ANLC
11 MMUT
DET-
12
MUT
13 SHIFT
14 WXC
4-5-3 EXPANDER (RF unit; IC17)
Pin Port
number name
2, 3,
T1–T4
10, 11
14 MOD70
15 MOD30
23 VOL
1 - 2
Description
Outputs control signal to the AF out
controller (Q35, Q36) for AF amplifi er
(IC6).
Outputs control signal to the ALC con-
troller (Q52).
Outputs control signal to the R5V
regulator (Q20).
Outputs control signal to the ANL
switch (Q21).
Outputs control signal for MIC mute
switch (Q51).
Outputs detector mute signal to the
AM/FM switch (IC2, pin 2).
Outputs shift control signal to the
VCO switch (Q57).
Outputs AM/FM (WX ch) select signal
to the AM/FM switch (IC2, pin 5).
Description
Outputs the bandpass filter tuning
control signal.
Outputs modulation control signal to
the buffer-amplifi er (IC18).
Outputs modulation control signal to
the ALC amplifi er (IC19).
Outputs AF volume control signal to
the AF amplifi er (IC6).