Aiwa CDC-R237 Service Manual page 17

• IC901 µPD178078GF-589-3BA (SYSTEM CONTROL) (MAIN BOARD)
Pin No. Pin Name
1 BATT IN
2 DFP IN
3 LCD DI
4 LCD DO
5 LCD CLO
6 LCD CE
7 BBE1
8 CDS DI
9 CDS DO
10 CDS CLO
11 – 15 NC
16 BBE2
17 NC
18 EVOL CLO
19 EVOL DO
20 EVOL CE
21 LOC/DX
22 DSSA CONT
23 ACC DETECTOR
24 PHONE MUTE
25 LEVELIND
26 TEST
27 AVDD
28 – 30 NC
31 FM/AM S METER
32 AVSS
33 REGCPU
34 VDD
35 REGOSC
36, 37 X2, X1
38 GND
39 IF REQ
40 GND
41 AM IF
42 FM IF
43 VDD PLL
44 FM OSC
45 AM OSC
46 GND PLL
47 EO 0
48 EO 1
49 IC
50 RESET
51 RDS CLK IN
52 ACC IN
53 NC
54 ST IND/SD IN
55 NC
56 ST BY MUTE
57 POWER CONT
58 RDS DI
59 BEEP
I/O
I Battery signal input
I Front panel with/without detect signal input
I LCD serial data signal input
O LCD serial data signal output
O LCD sync clock signal output
O LCD driver CE signal output
O Not used. (Open)
I CDS serial data signal input
O CDS serial data signal output
O CDS sync clock signal output
O Not used. (Open)
O Not used. (Open)
O Not used. (Open)
O Clock signal output to electronic volume
O Serial data signal output to electronic volume
O CE signal output to electronic volume
O LOC/DX select signal output
O DSSA control signal output "H": DSSA L/R
I Power supply overvoltage detect signal input
I External mute control signal input
I Level signal input
— CDS test mode pin
— Power supply pin (+5 V)
I Not used. (Connect to ground.)
I RDS AF signal input/FM/AM S meter signal input
— Ground pin
— Regulator for CPU power supply
— Power supply pin (+5 V)
— Regulator for oscillator circuit
— System clock oscillator pin (6.3 MHz)
— Ground pin
O IF count signal request output
— Ground pin
I AM IF count signal input
I FM IF count signal input
— Power supply pin for PLL (+5 V)
I FM local oscillator signal input
I AM local oscillator signal input
— Ground pin for PLL
O Error out signal output from charge pomp
O Error out signal output from charge pomp
— Not used. (Connect to ground.)
I System reset signal input
I RDS clock signal input
I ACC on/off detect signal input
I Not used.
I FM receive stereo signal input
O Not used. (Open)
O ST-BY mute control signal output to power IC
O Power control signal output
I RDS serial data signal input
O Beep signal output
Pin Description
CDC-R237
17