Forum Discussion
Occasional ContributorSignalTap Invalid jtag (completely wiring dependent)
Ouch.
Have you tried slowing the JTAG clock or making sure you have the JTAG timing constraints in your .sdc:
https://www.intel.com/content/www/us/en/docs/programmable/683081/22-2/jtag-signals.html
https://www.intel.com/content/www/us/en/support/programmable/articles/000084236.html
Occasional ContributorHi sstrell,
Thanks for your attention.
I've never seen or captured samples mismatch, or no triggering.
My "reliable" means "Invalid JTAG Chain", the device is never more than 60% filled. Meeting timing means no timing error other than unconstrained warnings (those are expected with SignalTap insertions).
Basically, as long as I am able to see SignalTap after programming. I am happy. There is 10% percent chances I don't see it. Tried clean, rebuild. noprune attributes, all sorts. Most of the time, I had to use alternative method or nets to get moving.
Regards,
