I have some home made boards which use a small custom JTAG header with VCC, GND, TDI TDO TCK TMS RST and EMU.
I use a little converter board that picks out said signals off the Analog JTAG header and a 2 inch FFC cable over to the board.
The ICE-1000 as well as the ICE-100B work like a charm on the board.
If I use my HPUSB-ICE, I have to reduce speed all the way down to 5MHz AND enable single byte transfer.
Otherwise the board ends in "unknown exception" and I occasionally drop into the startup .S file.
JTAG frequencies up to 50MHz can pass the JTAG test and the processor is found ... it just does not work.
Any fixes so I can use my "good" JTAG ???