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Altera_Forum
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18 years ago

Cyclone II programming problems

Hi all -- I've built a few PCBs based on Cyclone II FPGAs. Some of these boards, and especially the last, suffer from an annoying problem: When connecting the FPGA to the JTAG cable, Quart...
Altera_Forum's avatar
Altera_Forum
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18 years ago

Hi there Dennis,

First off, sorry for this short mail but we are currently at CeBit so I don't have much spare time.

I was able to track the problem down by trying to configure the FGPA with an old parallel ByteBlaster instead of the USB blaster. This worked fine, so I looked at the difference between their signals. Seems like the overshoot of the USBblaster is too large, so I placed a small capacitor (I think some tens of picofarads, could be more) between TCK and ground.

This completely solved the problem!

Let me know if this works for you as well.

Kind regards,

Riemer Grootjans