01-23-2011 05:58 PM
anyone familiar with the xapp875?
i using this design in Virtex6, to dealing with OC3(155M) using GTX.
the NGC provided in xapp875 works well, but the GTX has some problems:
1、the gtx setting is:"
reference clock: 155.52Mhz, PLL clock 1.5552Ghz;
data width/clk div/line rate: 20/1/3.1104G
TX buffer/Rx buffer Selected..
others : no selected.
2、setting the gtx as farend loop back at PMA, it works well, all packet loopback corectly
3、but...when setting to PCS loop back, some packet is dropped as FCS error....
I think there is nothing setting at PCS layer, no coding/decoding no comma detect....
why this happened?
is there anything I can do?or is this DRU design can't use at OC3?