In an application with the ADV7511 output connected to a crosspoint switch, there is no need for the DDC port.
The ADV7511 HUG states:
Unused Inputs - Any input data signals which are not used should be connected to ground.
To me, this implies that this statement applies to the input data port of the device.
How should the un-used DDC port be connected? If the port must be pulled up, can it be pulled to 1.8V since the input port is designed for 1.8V operation?
More searching - I found similar unanswered question in this discussion http://ez.analog.com/message/115384#115384