One of the unique features of the RX ADC peripheral is the inclusion of a self-diagnostic feature which simplifies the verification of the operating status of the ADC system. When enabled, the diagnostic feature performs a test A/D conversion using one of several internal reference voltages. The value can then be read from the results register and can be compared to external system signals which are converted. Typically, the self-diagnostic is performed as follows. First, the ADC unit is set to Single Mode. Then analog input channel AN0 is selected. Next, the A/D conversion is triggered using the software trigger. When the conversion is finished, the data can be read from data register A and the result verified.