JVC 340 SC, 330, 370 SC service manual General I/O, Input Description

Chapter 2—Functional Descriptions

Table 2-8VDB Serial Bus Information

Bus	I/O	Information	Description
IIC	O	Front/Rear convergence	TTL level that indicates whether the X-
		indication	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 2-9Vertical 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 (-).

2-38 Model 330. 340SC, and 370SC Service Manual