Sony SLV-789HF - Video Cassette Recorder, Service Manual, Page: 58 / 135

5-2
5-3. SYSTEM CONTROL — SYSTEM CONTROL PERIPHERAL CIRCUIT INTERFACE
(MA-342 BOARD IC160)
5-4. SYSTEM CONTROL AND RF MODULATOR — INPUT SELECTION BLOCK
INTERFACE (MA-342 BOARD IC160)
Signal
RESET
I2C DATA 1
I2C CLOCK 1
I2C DATA VIDEO
I2C CLOCK VIDEO
(ARC) S OUT 1
(ARC) CLK 1
Pin No.
MA-342 Board
IC160
#¢
MA-342 Board
IC160
#™
MA-342 Board
IC160
#¡
MA-342 Board
IC160
&™
MA-342 Board
IC160
&¡
MA-342 Board
IC160
$™
MA-342 Board
IC160
$¡
I/O
I
I/O
O
I/O
O
I/O
O
I/O level
Normally “H”, “L” when service interruption detected or restored.
Serial communication data to EEPROM I2C161.
Serial communication clock to EEPROM I2C161.
Serial communication data to video and audio microprocessor.
Serial communication clock to video and audio microprocessor.
Serial communication data to ARC microprocessor.
Serial communication clock to ARC microprocessor.
Signal
ANT SEL
Pin No.
MA-342 Board
IC160
@¡
I/O
O
I/O level
“L” when RF modulator through.
5-5. SYSTEM CONTROL — VIDEO/RP BLOCK INTERFACE (MA-342 BOARD IC160)
Signal
RF SWP
QVD
C SYNC
Pin No.
MA-342 Board
IC160
!•
MA-342 Board
IC160
!£
MA-342 Board
IC160
%•
TAPE
LOADING
*1
L
*3
TAPE
UNLOADING
*1
L
*3
STOP/FF
/REW
*1
L
*3
PB
*1
*2
*3
REC
*1
L
*3
I/O
O
O
I
REC/
PAUSE
*1
L
*3
*1. Synchronized with drum rocation, 30Hz 50% duty pulse.
*2. Normal “L”, “H” when video signal is not rgenerated.
*3. Composite sync signal (positive).
5-6. SYSTEM CONTROL — AUDIO BLOCK INTERFACE (MA-342 BOARD IC160)
Signal
A MUTE
AF REC P
Pin No.
MA-342 Board
IC160
^£
MA-342 Board
IC160
@™
TAPE
LOADING
L
L
TAPE
UNLOADING
L
L
STOP/FF
/REW
L
L
PB
L
L
REC
L
L
I/O
O
O
REC/
PAUSE
H
H