Agilex 7 F/I Series True Differential Input Termination

Thanks Frank. 

Yes the documentation was not clear to me w/ regard to AC coupling/internal biasing. 

I was able to get my hands on an Agilex -7 F series board and took some measurements of an AC coupled LVDS input. In this case the internal OCT was not enabled and there was an external 100 ohm termination resistor present on the Agilex side of the series AC coupling caps. 

With no bias resistors at all on Agilex side of AC coupling caps: A single leg oscillated ~940mV to ~1.17V. So common mode of 1.055V and VID of 0.21V. 

With a 10k pullup to 1.2V and a 10k pull down to GND on each leg (so should set a 0.6V bias for each leg: Swing of a single leg was from ~480mV to ~720mV. So Common mode of ~0.6V and swing of ~0.24V