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Altera_Forum
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15 years ago

Error: Can't access JTAG chain

When i try to program the FPGA cyclone III i get this error : error: can't access jtag chain error: operation failed. I am using a FPGA cyclone III .I would be able to program it a few months...
Altera_Forum's avatar
Altera_Forum
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14 years ago

Even with no clock at all, the FPGA should respond on the JTAG connection. The problem is probably somewhere else that the crystal. Check the power supplies, ground connections, impedances on the JTAG lines, etc... Check also the JTAG signals with a scope, especially the clock that is often the source of JTAG problems.

As for the voltage levels, you can check the input/outputs characteristics of your FPGA in the literature and see if you can use an I/O standard that is compatible with those voltage levels.