Awesome, side channels for the win. That said, I&#x27;m really surprised that JTAG couldn&#x27;t read out the ROM, in theory that is how you would program it. And given that you couldn&#x27;t program it, if instead of a minimal USB driver you wrote a program that read a 16 bit word at a time from ROM and stored it in a static variable you should be able to use the JTAG data watch function to stream out the words as you read them.