14.6.3.3 Selecting the Clock Source for a Peripheral

When changing a peripheral clock source by writing to the PCHCTRLm.GEN bit, the peripheral clock must be disabled before re-enabling it with the new clock source setting. This prevents glitches during the transition:

1. Disable the Peripheral Channel by writing PCHCTRLm.CHEN = 0.
2. Verify that PCHCTRLm.CHEN reads '0'.
3. Change the source of the Peripheral Channel by writing PCHCTRLm.GEN.
4. Re-enable the Peripheral Channel by writing PCHCTRLm.CHEN = 1.
5. Assert that PCHCTRLm.CHEN reads '1'.