Sony CDX-A251C Service Manual page 36

CDX-A251C
IC501 MB90487APF-G-171E1 (SYSTEM CONTROL) (MAIN BOARD (3/4))
Pin No. Pin Name
1 AREASEL2
2 AREASEL1
3 AREASEL0
4 COL_SW
5 BEEP
6 CYRIL_SEL
7 NOSE_SW
8 DIAG
9 VOLATT
10 NCO
11 VSS
12 TUATT
13 NSMASK
14 ILLUMI_SEL1
15 ILLUMI_SEL2
16 to 22 NCO
23 VCC5
24 EEP_SIO
25 EEP_CKO
26 AMPSTB
27 LCD_CE
28 LCD_SO
29 LCD_CKO
30 RDS_ON
31 RE_IN0
32 RE_IN1
33 I2C_CKO
34 I2C_SIO
35 DAVDD
36 AVRH
37 DAVSS
38 QUALITY
39 VSM
40 KEYIN1
41 KEYIN0
42 VSS
43 RC_IN0
44 to 48 NCO
49, 50 MD0, MD1
51 MD2
52 KEYACK
53 TU_ATTIN
54 BUIN
55 NCO
56 DAVN
57 NCO
58 UNISI
59 UNISO
36
I/O
I Destination setting pin (L: US, CND, E, MX model, H: AEP, UK model)
I Destination setting pin (L: AEP, UK, E, MX model, H: US, CND model)
I Destination setting pin (L: 9K, H: 10K)
I Illumination color select signal input (Fixed at H in this set)
O Beep signal output to power amp IC.
I Cyril select signal input (Fixed at L in this set)
I Front panel detach detection signal input
I Status signal input from power amp IC.
O Attenuator control signal output to electronic volume IC.
O Not used. (Open)
— Ground
O Tuner mute control signal output
O Noise mask signal output (AEP, UK model)
I Illumination voltage setting pin (Fixed at L in this set)
I Illumination voltage setting pin (Fixed at H in this set)
O Not used. (Open)
— Power supply pin (+3.3 V)
I/O Serial data signal input/output for EEPROM communication.
O Serial clock signal output for EEPROM communication.
O Standby signal output to power amp IC.
O Chip enable signal output to LCD drive IC.
O Serial data signal output to LCD drive IC.
O Serial clock signal output to LCD drive IC.
O RDS ON signal output (AEP, UK model)
I Rotary encoder signal input 0
I Rotary encoder signal input 1
O I2C bus serial clock signal output
I/O I2C bus serial data signal input/output
— Power supply pin for A/D converter. (+3.3 V)
— External reference power supply pin for A/D converter. (+3.3 V)
— Ground for A/D converter.
I Noise detection signal input (AEP, UK model)
I S meter voltage detection signal input
I Key signal input 1
I Key signal input 0
— Ground
I Rotary commander key signal input
O Not used. (Open)
I Signal input for operation mode designation. (Fixed at H in this set)
I Signal input for operation mode designation. (Fixed at L in this set)
I Key acknowledge detection signal input
I Tuner mute zero cross detection signal input (AEP, UK model)
I Backup power supply detection signal input
O Not used. (Open)
RDS data block synchronized detection signal input from RDS demodulator IC.
I
(AEP, UK model)
O Not used. (Open)
I SONY-BUS data signal input
O SONY-BUS data signal output
Pin Description