32.5.3 Accumulate Mode
In Accumulate mode (ADMD = 001
), after every conversion, the ADC result is added to the ADACC register.
The ADACC register is right-shifted by the value of the ADCRS bits. This
right-shifted value is copied in to the ADFLT register. The Formatting mode does not affect
the right-justification of the ADACC value. Upon each sample, ADCNT is also incremented,
incrementing the number of samples accumulated. After each sample and accumulation, the
ADACC value has a threshold comparison performed on it (see Threshold Comparison) and the ADTIF interrupt may
trigger.