Interrupts for the ACT module are enabled by setting the Clock Recovery Interrupt Enable (CRIE) bit in the PIE6 register. Along with the CRIE bit, peripheral interrupts need to be enabled by setting the Peripheral Interrupt Enable (PEIE) bit in the INTCON register. Once those interrupts are enabled, the Global Interrupt Enable (GIE) bit of the INTCON register needs to be set to enable interrupts to take place.
The Clock Recovery Interrupt Flag (CRIF) bit of the PIR6 register will be set
when the ACTLOCK or ACTORS bits change state and the module is enabled (ACTEN =
1). This generates an interrupt whenever the ACT module changes
state. Interrupts will not be generated for each OSCTUNE update unless that update
results in a change of lock status.