Vizio L42HDTV10A Service Manual page 46

1. TMDS Digital Core
The core performs 10-to-8-bit TMDS decoding on the audio and video received from the three
TMDS differential data lines along with a TMDS differential clock. The TMDS core supports link
clock rates to 165MHZ, including CE modes to 720P/1080I/1080P.
2. Active port detection
The Pane Link core detects an active TMDS clock and actively toggling DE signal. These states
are accessible in register bits, useful for monitoring the status of the HDMI input or for
automatically powering down the receiver. The 5V supply from the HDMI connector is used as a
cable detect indicator. The MT8293 can monitor the presence of this+5V supply and, if and when
necessary, provide a fast audio mute without pops when it senses the HDMI cable pulled. The
microcontroller can also poll registers in the MT8293 to check whether an HDMI cable is
connected.
3. HDCP Decryption
The MT8293 external EEPROM for encrypt HDCP keys. HDCP decryption contains all
necessary logic to decrypt the incoming audio and video data. The decryption process is
entirely controlled by the host microprocessor through a set sequence of register reads
and wires through the DDC channel. Pre-programmed HDCP keys and key Selection
Vector are used in the decryption process. A resulting calculated to an XOR mask during
each clock cycle to decrypt the audio/video data in sync with the host.
4. Video Data Conversion and Video Output
The MT8293 can output video in many different formats
CONFIDENTIAL – DO NOT COPY
as shown in the following figure.
Page 7-27
File No. SG-0198