Chapter 2—Functional Description
Model 330, 340SC and 370SC Service Manual
2-39
+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
Output
Description
/IICINT
IIC interrupt line. Signal line for slave boards to inform the SCB (master)
that there is data to be transferred. Master then polls slaves to
determine the source of the interrupt.
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
/PCST
Clock signal to start T/B pincushion, T/B Keystone, and horizontal
linearity correction.
Video Processor Board
Outputs
Description
HPARAB
Parabolic signal at horizontal frequency for dynamic focus.
VPARAB
Parabolic signal at vertical frequency for dynamic focus.
/SWEEPOK
Low indicates that all six sweeps are occurring at normal frequencies.
Horizontal Deflection Board
Inputs
Description
HSENSRED
+15V indicates red horizontal flyback occurring at normal frequencies.
HSENSBLU
Similar to HSENSRED.
HSENSGRN
Similar to HSENSRED.
HFDBCK
Voltage representing amount of horizontal scan drive. Used for modifying
amount of side pincushion and keystone when changing horizontal
frequency.
WIDTH
Positive DC voltage representing commanded width of the raster. Used for
generation of horizontal linearity ramp and T/B pincushion correction
waveform.
VERTDR
Pulse signal at vertical frequency from the vertical oscillator on the HDB.
HLINR
Voltage representing commanded horizontal linearity correction.
TBKEYCOR
Voltage representing commanded top and bottom keystone correction.