20.2 Overview

The Voltage Reference (VREF) peripheral provides control register for the voltage reference sources used by the AC peripheral. The user can select the reference voltages for AC0 by writing to the appropriate registers in the VREF peripheral.

In the default configuration for VREF, a voltage reference source is automatically enabled when requested by a peripheral. The user can enable the reference voltage sources and thus override the automatic disabling of unused sources by writing to the respective ALWAYSON bit in the AC Reference Control (VREF.AC0REF) register. This decreases the start-up time but comes at the cost of increased power consumption.