Chapter 2—Functional Descriptions
2-50
Model 330. 340SC, and 370SC Service Manual
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)
