The REFCLK/SYNC input does not need to be used. Can this input be left floating
or what termination is otherwise
Also Port B is not being used, can these inputs be left floating?
You can float the REFCLK pins when you drive DACCLK. When you use only one of
the two channels, you can float the unused input.
For Port B, you just need to tie the Frame inputs to LVDS logic low if you are
not using Port B, they can cause problems when you float them.