PC I/F (Basic Signal Path)
Overview
The PC I/F board main functions are to take the main, sub-picture and PC inputs from the A/V unit and analog to
digital convert each signal, perform I/P conversion, add on screen display information and output the picture
data to the plasma display as a DVI signal with content protection.
Main Picture
From the A/V unit the main picture RGB information from IC803 is sent through one of two filters (IC810 a 6.7mhz
low pass filter used for 15k signals or IC811 a 30mhz low pass filter used for 31k signals) after filtering out any
noise the RGB and sync signals enter IC4 for analog to digital converting. The digital RGB output from IC4 is
parallel 2 phase 8 bits for each signal. R=8x2, G=8x2 and B=8x2 total 6x8=64 bit. The PC input enters IC4 directly
and is processed the same.
Sub-Picture
The sub-picture Y/cb/cr and sync signals from the A/V unit exit IC802 and are sent through IC804 a 6.7mhz low
pass filter and enter IC310 on the PC I/F board. IC310 takes the Y/cb/cr signals and digital to analog converts
them outputting to IC25 parallel Y=8, cb=8 and cr=8 total 3x8=24 bits.
Video Processing
IC25 is the main digital video processor and this IC performs the I/P conversion and scaling to match the
digitalized video with the output resolution. IC25 detects the video resolution from the input sync. The video
processor also adds the onscreen display and processes the split screen modes 50/50 or freeze. IC25 outputs the
processed digital RGB to IC413 as a parallel 3x8=24 bits at 80mhz. IC413 is a panel link transmitter. It converts
the 8 bit RGB video data output from IC25 into the differential TMDS signal and then digitally transmits the
converted signals to the plasma display at 10x the clock frequency (800mhz) 4 channel serial 2 phase with HDCP
protection.