The following steps are recommended in order to initialize ADC operation:
- 1.Configure the resolution by writing
to the Resolution Selection bit (RESSEL) in the Control A register (ADC.CTRLA).
- 2.Optional: Enable the Free-Running mode by writing a '1' to the Free-Running bit
(FREERUN) in ADC.CTRLA.
- 3.Optional: Configure the number of
samples to be accumulated per conversion by writing the Sample Accumulation Number
Select bits (SAMPNUM) in the Control B register (ADC.CTRLB).
- 4.Configure a voltage reference by
writing to the Reference Selection bit (REFSEL) in the Control C register
(ADC.CTRLC). Default is the internal voltage reference of the device (VREF, as
configured there).
- 5.Configure the CLK_ADC by writing to
the Prescaler bit field (PRESC) in the Control C register (ADC.CTRLC).
- 6.Configure an input by writing to the
MUXPOS bit field in the MUXPOS register (ADC.MUXPOS).
- 7.Optional: Enable Start Event input by
writing a '1' to the Start Event Input bit (STARTEI) in the Event Control register
(ADC.EVCTRL). Configure the Event System accordingly.
- 8.Enable the ADC by writing a '1' to
the ENABLE bit in ADC.CTRLA.
Following these steps will initialize the ADC for basic measurements, which can
be triggered by an event (if configured) or by writing a '1' to the Start Conversion bit
(STCONV) in the Command register (ADC.COMMAND).