38.3.2.2 Selection of Negative Inputs

Negative input selection is determined by the setting of the DIFFx bit of the ADCIMCON1 register. The DIFFx bit allows the inputs to be rail-to-rail and either single-ended or differential. The SIGNx and DIFFx bits in the ADCIMCON1 register scale the internal ADC analog inputs and reference voltages and configure the digital result to align with the expected full-scale output range.

For the shared ADC module, the analog inputs have individual settings for the DIFFx bit. Therefore, the user has the ability to select certain inputs as single-ended and others as differential while being connected to the same shared ADC module. While sampling, the signal changes on-the-fly as single-ended or differential according to its corresponding DIFFx bit setting.