Redboard Turbo DAC reference voltage

This has probably been answered before, but I am unable to locate anything in the forums. I am attempting to determine the actual reference voltage for the digital-to-analog converter (DAC) on the SAMD21 based Redboard Turbo board (DEV-14812) whenever the DAC has been set to use the internal reference. Is it just the 3.3V maximum of the DAC?

The default is 3.3 volts, bur it’s adjustable to other voltages. See the SAMD section of [this page for more information.](analogReference() - Arduino Reference)