38.3.4 Selecting the Conversion Trigger Source

Class 2 inputs to the ADC module can be triggered for conversion either individually or as part of a scan sequence. Class 3 inputs can only be triggered as part of a scan sequence. Individual or scan triggers can originate from an on-board timer or output compare peripheral event, from external digital circuits connected to INT0, from external analog circuits connected to an analog comparator or through software by setting a trigger bit in an SFR.

Note: When conversion triggers for multiple Class 2 analog inputs occur simultaneously, they are prioritized according to a natural order priority scheme based on the analog input used. AN6 has the highest priority, AN7 has the next highest priority and so on.