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Altera_Forum
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16 years ago

Jtag Problem

Hello everybody, i have big problem, i use CIII FPGA on my own board (EP3C16Q240). I try use USB BLASTER (Rev. B), but this is response: Error: Can't access JTAG chain Error: Operation f...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

1. Recent Quartus versions have a JTAG Chain Debugger included with the programmer tool, that can help to detect hardware problems.

2. The most serious problem with the Rev. B JTAG flex print is, that it can break rather easily. A short IDC cable can replace it without problems.

3. The JTAG interface isn't very sensitive to signal quality issues. Basically, TCK is the only signal that can cause transmission errors due to excessive ringing on bad designed boards, all other signals are only sampled at TCK edges.