JVC 330, Service Manual

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Chapter 2—Functional Description
Model 330, 340SC and 370SC Service Manual 2-49
IIC O VIDOK Tells SCB that no VABs are reporting problems.
IIC O SWEEPOK Tells SCB that all sweeps are operating.
IIC O BEAMDET Tells SCB that beam current limiting is occurring.
BUS I/O Information Description
Serial I REDBIAS Commanded amplitude of red LCLV bias.
Serial I GRNBIAS Commanded amplitude of green LCLV bias.
Serial I BLUBIAS Commanded amplitude of blue LCLV bias.
Serial I RCONT Commanded red contrast.
Serial I GCONT Commanded green contrast.
Serial I BCONT Commanded blue contrast.
Serial I BRIGHT Commanded brightness level.
General I/O
This section provides a comprehensive description of the inputs to and outputs
from the VPB. The I/O description are arranged by the source/destination of the
signal and so the assemblies communicated with are used as the primary heading
of each group of signals and then are further subdivided into inputs and outputs. In
each case, the signal's direction is noted, with input referring to an input to the
RTG, and output to an output from the VPB. (e.g.: under Raster Timing Generator
'Input'; VSYNC refers to the signal VSYNC that is an input to the VPB from the
Raster Timing Generator). When test points are provided for the I/O they are
noted.
Table 2-11. Video Processor Board I/O Signals
System Controller Board
Input Description
IICCLK IIC clock line. Unidirectional clock line for control of
synchronous data transfer over IIC data bus.
BONSCRN Along with RONSCRN, GONSCRN, VONSCRN,
VIDBLANK, and DCRSTR (the later two on from the
RTG board) determines whether there is full brightness,
black, gray-scale, or external video presented in blue at a
given point on the screen.
RONSCRN Similar to BONSCRN.
GONSCRN Similar to BONSCRN.
VONSCRN Determines if internal test patterns will be shown.
VIDTEST Internal gray-scale video input information. Real time data 0V
to 1V.
RSENS Sensitivity (Z-axis gain) correction information for red. Real
time data at 0V to 1V.
GSENS Similar to RSENS.
BSENS Similar to RSENS.