11-14-2017 10:06 AM - edited 11-14-2017 10:07 AM
does anyone know how to get the "Loss Of Sync" in Virtex 7's GTX Serdes?
I searched for some informations on internet and I found Virtex 6 has a LOS Finite State Machine but Virtex 7 has none.
I simulated in ModelSim this SerDes to try to get LOS. I tied to '0' RXP and RXN serial ports and wait for some time:
1) I expected CPLL to unlock, but it did happen nothing.
2) I only receive random RXData from the SerDes
Can anyone help me?
11-14-2017 10:25 AM - edited 11-14-2017 10:40 AM
That is true 7-series GTX does not have this. You would need to make your own from the description of the LOS of sync in the 6-series user guide. For an 8B10B protocols you would be looking for disparity errors and not in table errors.
11-14-2017 10:27 AM
I believe your looking to know about the block synchronization , 64B/66B and 64B/67B protocols depend on block synchronization to determine their block boundaries. Block synchronization is required because all incoming data is unaligned before block lock is achieved. The goal is to search for the valid synchronization header by changing the data alignment. The RXGEARBOXSLIP input port is used to change the gearbox data alignment so that all possible alignments can be checked in normal mode.
11-17-2017 08:38 AM
thanks for the quick replies. This is how I expected: no LOS handling. I suppose that i can resolve this lack counting the number of Disp Err or Align Err to go in LOS state when it exceeded the decided threshold.