MPC551x: Internal Watchdog resets the CPU while debugging

Possible solutions

Disable internal watchdog

The Internal Watchdog must be disabled because the Watchdog is not stopped when the application is stopped (microcontroller is in the debug mode). In such case, the Watchdog could reset the microcontroller while the application is stopped and the debugger would lose the control over it. 

Set WTE bit in the RCHW (Reset Configuration Halfword) to 0

Write 0x01 to the RCHW instead of 0x05