John,
I did something similar to this in a Spartan II. I was searching through a 2^7-1 PRBS pattern (at the output of a SERDES, data bus is
10-bits wide) for the longest string of zeros. Granted the longest string of zeros in a 2^7-1 PRBS pattern is 6, the idea could be extrapolated to longer strings like 9 in a 65-bit wide bus.Here's an example of what I did for searching for 6 zeros in a row. You'll notice that in my casez statement, I'm actually searching for 6 ones in a row. This is because the BERT that I was using inverted it's output PRBS pattern.
always @(posedge clock1) begin casez (datasi[9:0]) 10'b???111111? : Q[9:0] = {datasi[9:8],7'b1111111,datasi[0]}; default : Q[9:0] = datasi[9:0]; endcase end
Once you find the string that you're looking for, you can do what ever you'd like.
Hope this helps,
Jeremy