JVC 340 SC, 330, 370 SC service manual Rthresh, Gthresh, Bthresh, Raster Timing Generator, Vidblank

Chapter 2—Functional Descriptions

RTHRESH	Threshold (Z-axis offset) correction information for red. Real
	time data at 0V to 1V.
GTHRESH	Similar to RTHRESH.
BTHRESH	Similar to RTHRESH.
+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 (-).
+SERDATA	Serial data transfer. Unidirectional, differential, synchronous
	serial data communication line. Used for transferring data
	from SCB to other circuit boards. Uses SERCLK and IIC
	for control of receiver.
-SERDATA	Serial data transfer.
	System Controller Board
Outputs	Description
/IICINT	Interrupt used to tell the SCB that the VPB has data to report.
I/O	Description
IICDATA	IIC data line. Bi-directional serial line for synchronous data
	transfer between SCB and other circuit boards. See
	detailed description for list of signals transferred and data
	direction.
	Raster Timing Generator
Inputs	Description
VIDBLANK	Along with RONSCRN, GONSCRN, BONSCRN, and
	VONSCRN from the SCB, and DCRSTR, determines
	whether there is full brightness, black, gray-scale, or
	external video presented at a given point on the screen.
DCRSTR	Along with RONSCRN, GONSCRN, BONSCRN,
	VONSCRN, from the SCB, and VIDBLANK, determines
	whether there is full brightness, black, gray-scale, or
	external video presented at a given point on the screen.
Outputs	Description
SGSYNC	Stripped Green Sync. The composite sync signal stripped from
	the green channel
	(if it exists) (TP13).
HSYNC	Horizontal Sync. This can be either just the horizontal sync, in
	which case there will be a separate vertical sync, or
	HSYNC can be a composite sync. (TP14)
VSYNC	Vertical Sync. This cannot be a composite sync signal. (TP15)

2-50 Model 330. 340SC, and 370SC Service Manual