Forum Discussion
Farabi
Regular Contributor
3 years agoHello Simon,
How did you connect the JTAG chain? Suspect JTAG signal integrity issue when there is too long connection in the JTAG chain. Can tap this signal and observe in oscilloscope.
Its not quartus programmer issue.
regards,
Farabi
swm
New Contributor
3 years agoHello Farabi, thanks for your reply. I believe that I don't have a signal integrity problem on the USB chain due to the following experiements that did not involve changing the USB wiring:
- Disable some USB ports in software, effectively removing some FPGAs visible to jtagd. The remaining FPGAs could then be repeatedly programmed successfully without and reported errors.
- Run eight Docker containers each with one jtagd that can only see one FPGA. The FPGAs can then be repeatedly programmed reliably.
Do you know if USB-to-JTAG programming of at least eight FPGAs connected to one PC has been tested?