The figure below shows the timing diagram for the ADC when accumulating two samples in Accumulation mode.
Figure 1. Timing Diagram - Accumulated
Conversion
The number of samples to accumulate is configured with the Sample Number (SAMPNUM) bit field in the Control B (ADCn.CTRLB) register. The STCONV bit is set for the entire conversion. The total conversion time for n samples is given by:
Total Conversion Time (12-bit)