XR-L240 - Sony Car Audio Service Manual (repair manual). Page 25

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Pin No.

Pin Name

I/O

Description

1

VREF –

—

Reference voltage (0V) terminal (for A/D converter)

2

VSM

I

FM and AM signal meter voltage detection input from the FM/AM tuner unit (A/D input)

3 to 6

NC

—

Not used

7

NOISE-DET

I

Noise level detection signal input at SEEK mode (A/D input)

8

MPTH

I

Multi-path detection signal input from the RDS decoder

9

NC

—

Not used

10

VREF +

—

Reference voltage (+5V) terminal (for A/D converter)

11

VDD

—

Power supply terminal (+5V)

12

OSC2

O

Main system clock output terminal (18.432MHz)

13

OSC1

I

Main system clock input terminal (18.432MHz)

14

VSS

—

Ground terminal

15

XI

I

Sub system clock input terminal (32.768kHz)

16

XO

O

Sub system clock output terminal (32.768kHz)

17

GND (MMOD)

—

Setting terminal for the single chip mode     “L”: single chip

18

LCD-SO (TX)

O

LCD serial data output to the liquid crystal display driver

19

LCD-SI (RX)

I

LCD serial data input from the liquid crystal display driver

20

LCD-CKO

O

LCD serial transfer clock signal output to the liquid crystal display driver

21

TU-SDA

O

Serial data output to the FM/AM tuner unit

22

TU-SI

I

Serial data input from the FM/AM tuner unit

23

TU-SCL

O

Serial data transfer clock signal output to the FM/AM tuner unit

24

LCD-RES

O

LCD reset signal output to the liquid crystal display driver    “L”: reset

25

LCD-CE

O

Chip enable signal output to the liquid crystal display driver    “H” active

26

KEYACK

I

Key acknowledge signal detect input from the liquid crystal display driver

27

DAVN-RDS

I

RDS data request signal input from the RDS decoder    “H” active

28

B/U-IN

I

Battery detect signal input from the battery detect circuit    “L” is input at low voltage

29

NC

—

Not used

30

RAM BU

I

Internal RAM reset detection signal input terminal
Input terminal to check that RAM data are not destroyed due to low voltage
This checking is made within 100 msec after reset     “L”: RAM reset

31

TEST-IN

I

Setting terminal for the test mode    “L”: test mode    Normally: fixed at “H”

32

NCI

I

Not used

33

RESET

I

System reset signal input from the reset signal generator or reset switch    “L”: reset
“L” is input for several 100 msec after power on, then it changes to “H”

34

TU-ENABLE

O

Chip enable signal output to the  FM/AM tuner unit    “H” active

35

BEEP

O

Beep sound drive signal output to the power amp

36

POWER-ON

O

Main system power supply on/off control signal output terminal    “H”: power on

37

ILL-IN

I

Not used

38

ACC-IN

I

Accessory detect signal input terminal    “L”: accessory on

39

NC

—

Not used (open)

40

TEL-MUTE

I

Telephone muting signal input terminal    At input of “H”, the signal is attenuated by –20 dB
Not used

41

NCI

I

Not used

42

UNI-SO

O

Serial data output to the bus interface    Not used

43

UNI-SI

I

Serial data input from the bus interface    Not used

44

UNI-CKO

O

Serial data transfer clock signal output to the bus interface    Not used

45

SDA

I/O

Two-way data bus with the RDS decoder