20.2 Overview

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

A voltage reference source is automatically enabled when requested by a peripheral. The user can enable the reference voltage sources and override the automatic disabling of unused sources by writing to the respective ALWAYSON bit in VREF.ACREF, decreasing the start-up time at the cost of increased power consumption.