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working on the JTAG instruction for JTAG configuration
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Which FPGA?
Did you take a look at the JRunner code.
https://www.altera.com/download/legacy/jrunner/dnl-jrunner.html It should be fairly simply to trace the JTAG traffic, or to add debug statements to that code to determine the JTAG instructions.
The JRunner software has hooks for you to integrate your own custom I/O functions. If I wanted to know the JTAG instructions, I would re-write the I/O procedures such that the I/O toggles also controlled a software-based JTAG TAP machine, and then have that software log the instructions and data to file.
Cheers,
Dave
Honored Contributor
