LVDS Signal DC offset and AC Swing

Hi,

1- in order to eliminate confusing, I tried to create a new thread with the new question.

2- The reason to switch Transceiver, because of necessity. LVDS IO Block performance is limited by 1.434 Gbps. I need 2.5 Gbps.

3- I found the following document: It is for Cyclone 5 not for Cyclone 10. I just tried to figure out the capaility of transceiver. I am hoping this is same as Cyclone 10 GX

https://www.altera.co.jp/content/dam/altera-www/global/ja_jp/pdfs/literature/hb/cyclone-v/cv_55002.pdf

Sounds like, the following section of the document says that Vocm is programmable with Transceiver. Am I missing something?

In table 2-2,

A- Please check the second section called "Save Board Space and Cost"

B- From there, please see " On-Chip Biasing "

C- At this section, the comment says " Establishes the required transmitter common-mode voltage (TX VCM) level at the transmitter output. The circuitry is available only if you enable OCT. When you disable OCT, you must implement off-chip biasing circuitry to establish the required TX VCM level. "

Does this mean that Vcm is programmable? Am I missing something?