Hi, Rich, What are the frequencies of the various clocks? I think you want the OSERDES CLKDIV to be the same freq as the parallel data's clock. For 6 bit parallel data, you want the freq of the OSERDES CLK to be 6*freq(CLKDIV) in SDR mode and 3*freq(CLKDIV) in DDR mode. I think the same is true for the ISERDES. I'm not sure I'm discerning things correctly from the VHDL, but it looks like maybe you are running CLKDIV at 87.5 MHz instead of 125 MHz?
Dave
