I have a frdm k64f. I am running kinetis 3.0 with ksdk 1.3. I have modified the rtos Ethernet echo server example to continuously send the value of a timer that increments once per millisecond to a server on a laptop. I can run it and print the values the server gets on screen. Until it randomly stops because the MCU got dropped into the default ISR. This happens at random times 10+ minutes into continuous operation. What is the best way to debug what sent the CPU to the default ISR?