Olympus OEP-3, Service Manual

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4-43
OEP-3 V1 (UC)
4-4-3. VPR (Analog Video Block) Control
I
2
C bus control
Purpose
Controls the I
2
C bus circuit on the analog board.
Functions obtained by I
2
C bus control
User menu: HUE, COLOR, GAIN, OFFSET, MONI-R, MONI-G, MONI-B, IRE, SYNC ON G,
and INPUT SEL
Service menu: PICTURE, G DRIVE, B DRIVE, SUB-BRIGHT, and VBS Y
Other functions: HALFTONE
Remarks:
The object to be handled is an I
2
C-compatible circuit on the VPR-63 board. The center value for
adjustment is stored in I
2
C-EEPROM on the VPR board. During start, the SY-282 board reads data from
I
2
C-EEPROM and initializes the IC on the VPR-63 board. These set values can be changed (readjusted)
in the service man mode. No communication is performed when I
2
C-CTS is in the send disable (L) state.
Screen display-related signals
Purpose
Produces a pulse signal for screen display.
Signal line name I/O Description
OSD-R Output Screen display control data (R) H:active
OSD-G Output Screen display control data (G) H:active
OSD-B Output Screen display control data (B) H:active
OSD_BLK Output Screen display control data (Blanking) H:active
OSD_ON_NOFF Output Batch control of screen display superimposition (yes/no) H:active
OSD_HD Input Timing pulse (H-SYNC) Sync negative
OSD_VD Input Timing pulse (V-SYNC) Sync negative
Input signal switching control
Purpose
Specifies an input signal.
INPUT_SEL1 Contents
L VIDEO/S-VIDEO
H RGB
Signal line name I/O Description
IIC-SCL Output Serial data clock H:active
IIC_SDA Output Serial data H:active
IIC_CTS Input Serial data transfer enable H:active
Remarks:
VIDEO and S-VIDEO are switched by I
2 C control.