33.3.3.4.3 Free-Running Conversion
In Free-Running mode, a new conversion is started as soon as the previous conversion has completed. This is signaled by the RESRDY bit in the Interrupt Flags (ADCn.INTFLAGS) register.
The figure below shows the timing diagram for the ADC in Free-Running mode with single conversion.
The Result Ready event and the interrupt flag are set after each conversion. It is possible to combine accumulated conversion and Free-Running mode.
To safely change any of these settings when using Free-Running mode, disable Free-Running mode, and wait for the conversion to complete before doing any changes. Enable Free-Running mode again before starting the next conversion.