about this ICE thing ... back in the old days, an in-circuit- emulator was a device that replaced the in-circuit processor and ran the trace, etc, in parallel and in synchronization with the MCU in the circuit. That meant that it had to execute all the trace, and other support functions at the same time that it executed the target's code in real time. This required some really fancy hardware. The ones I used didn't have an MCU on board, but, rather, a custom set of logic that did the emulation.

Today's ICE simply runs a monitor program on another MCU. In some cases, it doesn't even do that, in that it only simulates running the monitor program on the host machine.

Presently, I'm using the freeware ULTRAMON51, which has a line-by-line assembler, disassembler, plus most other functions in a simple monitor. It works more conveniently if you configure the system memory such that you can "deMorganize" it, i.e. map both code and data into the same space, though that's not necessary in all cases. I find Ultramon51 adequate. One of these days, I'll rework it such that it uses an external UART, so I can use all the MCU resources for "useful work."

RE