The error "debug port fail" can happen with TRACE32 for ARC under the following circumstances:

• Stopping the core on SYStem.UP failed, because the core does not stop even after 1000ms.
  Try SYStem.Mode Attach instead of SYStem.Mode Up
• The JTAG Status Register of the ARC debug interface reports an error, by showing the Failure-Bit active.
  Try a lower JTAG frequency (e.g.: SYStem.JtagClock CTCK 1MHz).
• A read or write transaction to/from the ARC core does not complete. The JTAG Status Register does not show the Ready bit after waiting for 1000ms and even not after re-initializing the read/write-transaction and waiting for. Try a lower JTAG frequency (e.g.: SYStem.JtagClock CTCK 1MHz).
  Disable or disconnect any external source which resets the ARC core frequently (like e.g. a watchdog timer).