JVC 340 SC - Manual (Page 50)

Chapter 2—Functional Descriptions
2-38 Model 330. 340SC, and 370SC Service Manual
Table 2-8 VDB Serial Bus Information
Bus I/O Information Description
IIC O Front/Rear convergence
indication
TTL level that indicates whether the X-
convergence is in front screen mode (high)
or rear screen (pulled low).
IIC I Serial data load Command to the serial data receiver that the
incoming data is to be read.
Serial I VH Commanded vertical height of picture.
Serial I VCENTBLU Commanded vertical position of blue raster.
Serial I VCENTGRN Commanded vertical position of green raster.
Serial I VCENTRED Commanded vertical position of red raster.
Serial I TRAPCORR Commanded L/R keystone correction.
Serial I LRPNCORR Commanded L/R pincushion correction.
Serial I TBPNCORR Commanded T/B pincushion correction.
Serial I HLINCORR Commanded overall horizontal linearity
correction.
General I/O
This section provides a comprehensive description of the inputs to and outputs from the
VDB. 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
VDB. (e.g. under 'Raster Timing Generator', 'Input'; /PCST refers to the signal /PCST that
is an input to the VDB from the Raster Timing Generator). When test points are provided
for the I/O they are noted.
Table 2-9 Vertical Deflection 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.
RXCORR A 0-1 V signal from the bit-mapped memory on the SCB. 0.5V represents
no correction. This is a real time signal representing the X correction on
red.
RYCORR Similar to RXCORR.
GXCORR Similar to RXCORR.
GYCORR Similar to RXCORR.
BXCORR Similar to RXCORR.
BYCORR Similar to RXCORR.
+SERCLK Serial data transfer clock (+). Unidirectional, differential clock line from
SCB to other circuit boards. Used for synchronous control of serial
communication over SERDATA data lines.
-SERCLK Serial data transfer clock (-).