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JTAG and Boundary scan.

Posted: April 8th, 2018, 12:18 pm
by kg4pob
Hello all, I am new to posting so please be gentile on me. I am a repair tech for PLC's and do a lot of reverse engineering, or attempt to anyway. I am trying to learn to use JTAG and Boundary scan to troubleshoot, extract firmware and programs, for chip replacement and the ability use my own programs and then restore the original programming only. Not trying to steel anything only repair things. Most of what I work on has a JTAG connection be it FPGA, CPLD or some MCU. The boards I deal with have multiples of each.

With that being said, I have purchased the Mojo to try to learn how to better utilize these connections and some programming. What my ultimate goal would be is to be able to save the original programs, bit streams, etc. from these boards and be able to write or build my on programs to put in these boards to test things out. And also use boundary scan. So in trying to connect to the Mojo through JTAG, I do not detect the scan chain. I have run the update to make sure I have the latest frimware but still do not detect a scan chain. Is there something I'm missing, doing wrong?

Thanks in advance for any help.