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Oliver_I_Sedlacek's avatar
Oliver_I_Sedlacek
Icon for Contributor rankContributor
1 year ago

Windows 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% ...
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FvM's avatar
FvM
Icon for Super Contributor rankSuper Contributor
11 months ago

Hi,
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