When using a level 1 priority interrupt, it is important to make sure the Interrupt Service Routine is configured correctly as it may cause the application to be stuck in an interrupt loop with level 1 priority.
By reading the CPUINT STATUS (CPUINT.STATUS) register, it is possible to see if
the application has executed the correct RETI (interrupt return)
instruction. The CPUINT.STATUS register contains state information, which ensures that the
CPUINT returns to the correct interrupt level when the RETI instruction is
executed at the end of an interrupt handler. Returning from an interrupt will return the
CPUINT to the state it had before entering the interrupt.