> Perhaps you're running into some sort of meta-stability problem since > your clock and input are synchronous. Try lengthening one of the > cables a foot or so and see if it makes any difference.
I'd be very suspicious of a metastability problem if the results are even somewhat reproducible. Most of the quirks that get blamed on metastability are just simple setup/hold errors such that an input to a state machine has different values at different FFs. The two obvious causes are a longer delay on one path (more logic, longer routing) or slightly different setup times on the FFs so a signal gets to both at the same time and meets setup one one but doesn't the other one. -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts