34.3.1 Initialization
The following steps are required to operate the DAC:
- Select the DAC reference voltage in the Voltage Reference (VREF) peripheral by writing the appropriate Reference Selection bits.
 - Configure the further usage of the DAC
               output:
- Configure an internal peripheral to use the DAC output. Refer to the documentation of the respective peripherals.
 - Enable the output to a pin by
                  writing a ‘
1’ to the Output Buffer Enable (OUTEN) bit. The input for the DAC pin must be disabled in the Port peripheral (ISC = INPUT_DISABLE in PORTx.PINCTRLn). 
 - Write an initial digital value to the Data (DACn.DATA) register.
 - Enable the DAC by writing a
               ‘
1’ to the ENABLE bit in the Control A (DACn.CTRLA) register. 
