Forum Discussion
Oliver_I_Sedlacek
Contributor
ContributorWindows sees USB blaster but Quartus doesn't, why?
After using my USB blaster successfully with SignalTap to configure and debug my Cyclone4 part, SignalTap and the programming software aren't reliably seeing the USB blaster (by which I mean only 5% ...
FvM
Super Contributor
Super ContributorHi,
I understand your latest problem so that Signaltap is working on some boards and not on some others.
Can you narrow down what has changed?
- different FPGA image
- different PCB production charges
- different FPGA production lots
- BOM changes
It's well possible that newer FPGA production lots involve process modification, e.g. resulting in faster JTAG logic that is more responsive to TCK ringing. If the problem is about signal crosstalk, FPGA configuration changes can have a big impact.
Regards
Frank
