The subsystem allows the end-user to build an HDMI sink device, which negotiates with the targeted HDMI source device for supported features and capabilities. The communication between the source device(s) and the sink device is implemented through the DDC lines, which is an I2C bus included on the HDMI cable.
Note: The DDC signals can be
left disconnected when using the HDMI core in DVI only mode without HDCP.