Will a MCU recover from FLL Loss of Lock

[mjcoury]

I am catching my Unimplemented ISR... which was a LOLS which is a FLL Loss of Lock in the ICGS1 register.. If i clear this and the Interrupt will the MCU recover, so long as there is not something else driving this error...?


Thanks

[stevo10]

Hi,

In short, yes the MCU should recover.

The LOLS is a sticky indication of the FLL lock status. In the event that the FLL were to unexpectedly loss lock, the LOLRE (loss of lock reset enable) bit would determine the action - which would either be a reset request (LOLRE=1) or interrupt request (LOLRE=0).

In most cases if an interrupt is requested the software will loop in the service routine until the lock is reengaged. Also note that the LOLS bit should be cleared here by reading the status register then writing a 1 to the ICGIF (iCG interrupt flag) bit in ICGS1.