Data Sheet

Interfaces
46 Datasheet, Volume 1 of 2
Auxiliary Channel (AUX CH) is a half-duplex bidirectional channel used for link
management and device control. The Hot-Plug Detect (HPD) signal serves as an
interrupt request for the sink device.
The processor is designed in accordance to VESA* DisplayPort* specification. Refer to
Table 2-26.
2.5.5 High-Definition Multimedia Interface (HDMI*)
The High-Definition Multimedia Interface (HDMI*) is provided for transmitting
uncompressed digital audio and video signals from DVD players, set-top boxes, and
other audio-visual sources to television sets, projectors, and other video displays. It
can carry high-quality multi-channel audio data and all standard and high-definition
consumer electronics video formats. The HDMI* display interface connecting the
processor and display devices uses transition minimized differential signaling (TMDS) to
carry audiovisual information through the same HDMI* cable.
HDMI* includes three separate communications channels: TMDS, DDC, and the
optional CEC (consumer electronics control). CEC is not supported on the processor. As
shown in the following figure, the HDMI* cable carries four differential pairs that make
up the TMDS data and clock channels. These channels are used to carry video, audio,
and auxiliary data. In addition, HDMI* carries a VESA DDC. The DDC is used by an
HDMI* Source to determine the capabilities and characteristics of the Sink.
Audio, video, and auxiliary (control/status) data is transmitted across the three TMDS
data channels. The video pixel clock is transmitted on the TMDS clock channel and is
used by the receiver for data recovery on the three data channels. The digital display
data signals driven natively through the PCH are AC coupled and needs level shifting to
convert the AC coupled signals to the HDMI* compliant digital signals.
The processor HDMI* interface is designed in accordance with the High-Definition
Multimedia Interface.
Figure 2-8. DisplayPort* Overview