Video Circuit Explanation
he A board serves as the entry point for all video signals that will be selectively
processed by the DG board via Video Switch IC3101. The main microcontroller, which
resides on the DG Board, is responsible for the selection of the designated video input
through the use of the I
2
Bus select lines. Two composite, two S–Video inputs, a
Component, a single Tuner, an HDMI video, and a DVD video interface are selectively
switched for video processing on the DG board. Connectors PA1 and DG1 serve as the
signal access point.
Video read from the SD Card is processed by the DVD main unit (M8 and RD)
where it enters the Video switch as DVD component Y/Pb/Pr video. Its output
appears on connector PA1 as Main Y/Pb/Pr video where it enters the DG board
on connector DG1 pins #37, 35, and 33.
HDMI video from the DV board enters the video switch as HDMI Y/Pb/Pr and is
also switched to the Main Y/Pb/Pr video input on the A Board
The NTSC tuner inputs, and the S-video and composite inputs to the video
switch appear on DG1 pin 37.
Video Path.
A Board
T
Figure 24
27
