Have you got an external watchdog connected. Or could there be noise on the reset line.
You may also have run away code execution perhaps a null pointer function call or you may have corrupted the ram contents used by the debugger.
In reply to Paul Brown:
M16C uses standard UART1 for communication with E8a.
Reconfiguraring UART1 can cause a time out error.
Changing clock source of UART 1 can cause a time out.
The debug monitor being executed in M16C needs 128 bytes RAM and 14 bytes of stack memory. Make sure your software does not write to this work RAM of the debug monitor and every tasks has 14 byte of stack left for the debugger.
Please have a look at the chapter "Notes on using E8a emulator" of the E8a User's Manual. This describes which resources are uses by the emulator and must not be modified by your software.
Can you see if your software is still working after you get the time out error? If your software crashes, this may also cause a problem for the debug monitor.
Thank you very much for answering this question. I'll look into this and reply back.
In reply to FrankL:
Thank you very much for answering this question. I'll look into this and reply.