We're trying to bring up the LS1020a on our custom board. We're having trouble connecting via JTAG (CWTAP via USB) to the bare board in order to flash our RCWs into QSPI flash. The sequence fails on "reset_to_debug" before we can even load our RCW override value. We noticed on the LS1021ATWR dev board, that executing reset_to_debug causes a PORESET pulse. According to the LS1021a ARM, PORESET should also assert TRST, but not neccessarily vice versa. My questions are:
Why does "reset_to_debug" cause assertion of PORESET on the LS1021ATWR board? And, should our design also assert PORESET when we use CCS to execute "reset_to_debug"?