SWRU626 December 2025 CC3501E , CC3551E
The ADC voltage reference (VR+) can be configured through the VRSEL bits in the MEMCTL register. Different reference sources can be selected for conversion on different channels. There are two options available for supplying a reference voltage to the ADC:
When supplying an external reference to the ADC, the VPP pin is connected to the reference source with the appropriate decoupling circuitry.