XR-C7220, XR-C7300, XR-C7300W - Sony Car Audio Service Manual (repair manual). Page 27

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Pin No.

Pin Name

I/O

Function

1

SEEKOUT

O

Seek control signal output to the FM/AM tuner unit (TU1)
AM mode: Used for IF count output/SD output request/AGC cut at SEEK or BTM
FM mode: Used for SD speed up at SEEK, BTM, or AF
“L” is output at tuner off

2, 3

NCO

O

Not used (open)

4

ST-MONO

I/O

FM stereo broadcasting detection signal input from the FM/AM tuner unit (TU1), or forced 
monaural control signal output to the FM/AM tuner unit (TU1)
“L” is input in the FM stereo mode, or “L” is output in the forced monaural mode

5

TUNMUTE

O

Muting on/off control signal output of the FM and AM tuner signal    “H”: muting on

6

FM-ON

O

FM system power supply on/off control signal output to the BA3918 (IC671)
“L”: AM power on, “H”: FM power on

7

TU-ON

O

Tuner system power supply on/off control signal output to the BA3918 (IC671)
“H”: tuner power on

8

VCC

—

Power supply terminal (+5V)

9

NCO

O

Not used (open)

10

BUS-ON

O

Bus on/off control signal output to the SONY bus interface (IC701)    “L”: bus on

11

SYSRST

O

Reset signal output to the SONY bus interface (IC701)    “L”: reset

12

DOORSW

I

Front panel open/close detection signal input    “L” is input when the front panel is closed

13

LCD SO

O

Serial data output to the liquid crystal display driver (IC901)

14

LCD CKO

O

Serial data transfer clock signal output to the liquid crystal display driver (IC901)

15

BEEP

O

Beep sound drive signal output terminal

16

LCD CE

O

Chip enable signal output to the liquid crystal display driver (IC901)    “H” active

17

UNISI

I

Serial data input from the SONY bus interface (IC701)

18

UNISO

O

Serial data output to the SONY bus interface (IC701)

19

UNICKO

O

Serial data transfer clock signal output to the SONY bus interface (IC701)

20

SD-IN

I

Station detector detect input from the FM/AM tuner unit (TU1)
Stop level for SEEK, BTM, etc. is determined    SD is present at input of “H”

21 to 23

NCO

O

Not used (open)

24

SIRCS

I

Sircs remote control signal input from the remote control receiver (IC951)

25

PLLSI

I

PLL serial data input from the FM/AM PLL (IC1)

26

PLLSO

O

PLL serial data output to the FM/AM PLL (IC1)

27

PLLCKO

O

PLL serial data transfer clock signal output to the FM/AM PLL (IC1)

28

PLLCE

O

PLL chip enable signal output to the FM/AM PLL (IC1)    “H” active

29

ILL-ON

O

30 to 32

NCO

O

Not used (open)

33

VSS

—

Ground terminal

34

C

—

Connected to coupling capacitor for the power supply

35

AD-ON

O

A/D converter power control signal output terminal
When the KEYACK (pin &§) that controls reference voltage power for key A/D conversion input 
is active, “L” is output from this terminal to enable the input

36

RE-IN0

I

37

RE-IN1

I

38

DVCC

—

Power supply terminal (+5V) (for D/A converter)

39

DVSS

—

Ground terminal (for D/A converter)

Power on/off control signal output of the illumination LED and liquid crystal display driver 
(IC901)    “H”: power on    Depends on initial setting of power select switch (S501)
Power select switch (S501) on: “H” output at the accessory on
Power select switch (S501) off: “H” output at the power on

Dial pulse input of the rotary encoder (RE900)
 (for VOLUME/BASS/TREBLE/BALANCE/FADER control)