Switching between the PLL and any non-PLL source is handled in the same manner as
any other clock source change.
When the
NOSC selects a source with a PLL, the system
continues to operate using the current oscillator until the new oscillator is ready.
When the new source is ready, the associated Status bit in the Oscillator Status (
OSCSTAT) register is set, and once the PLL is locked and ready for use, the
PLL is Ready (
PLLR) bit is set. Once both the source and PLL are ready, the
switch will complete.