What is the purpose of the rxencommaalign signal?
Rxencommaalign is driven high during the initial phase of sync / resync.
Its purpose is to communicate to the GTs in the JESD204 PHY that they should be receiving BC commas and that they should align to them.
When the JESD204 core has achieved code group sync (CGS) on every lane, rxencommaalign will drop. This will happen before SYNC is raised.