Hughes JVC 200, Service Manual

Page: 29 / 140

Chapter 2---System Description
LED indication
The RGB VIC includes an LED which glows when the board is
selected (i.e. when the /SEL_CH line is low) as the input for the
Model 200 Projector.
IIC serial bus interface section
The RGB_VIC is controlled by the serial bus interface. The IIC bus
comes from the System Controller Board through the Backplane
Board. The information transferred over the IIC bus is indicated
below (I = input to the RGB VIC, and O = output from the RGB
VIC). The RGB VIC does not use the interrupt line of the IIC bus
interface:
Table 2-2. Standard RGB VIC IIC communication
I/O Bits Information Description
I 1 /SEL_CH Select line for the RGB_VIC. Low = Selected
RGB_VIC.
O 4 VIC_ID VIC identification lines. 0000 for RGB_VIC.
O 1 VIC_MODEL Revision of the RGB_VIC.
O 1 /VIC_OK RGB_VIC status line. Low = operational
RGB_VIC.
The RGB_VIC I/O
This section provides a description of the inputs to and outputs
from the RGB_VIC. The I/O descriptions are arranged by the
source/destination of the signal. The format used is such that the
assembly communicated with is used as the primary heading of
each group of signals. Those signals are further subdivided into
inputs and outputs. Input refers to an Input to the RGB_VIC,
output refers to an output from the RGB_VIC.
Table 2-3. Standard RGB VIC I/O signals
Projector Inputs
INPUTS DESCRIPTION
RED
GREEN
BLUE Video input signals. about 0.7 to 1 VPP
HORIZ. Horizontal or composite sync signal
VERTICAL Vertical sync signal
Video Processor Board
OUTPUTS DESCRIPTION
Model 200 Service Manual 2-15