SLAZ519AA August 2014 – August 2021 MSP430FR69891
REF Module
Functional
REFON Feature
The Reference module does not not provide REF voltage to Comparator module when the REFON bit is set (REFCTL0.REFON=1).
1. Use REFBGOT bit of the REFCTL0 regsiter instead of REFON bit to provide REF voltage to Comparator.
OR
2. Enable the Comparator module with internal REF setting (CEREFL + CERS bits of the CECTL2 register) to request the REF module.