36.4.2.2 Selecting Comparator Inputs

Each comparator has one positive (COMPn-AINP) and one negative (COMPn-AINN) input, which may be chosen from a selection of shared analog I/O pins and internal inputs. COMPn-AINP and COMPn-AINN are configured by writing to the Positive and Negative Input Selection bit fields in the Comparator n Comparator Control A register (COMP[n].COMPCTRLA.MUXPOS/MUXNEG), respectively. For details about the possible input selections, refer to the MUXPOS and MUXNEG bits in the COMP[n].COMPCTRLA register description.

Note:
  1. Before using any I/O pins as comparator inputs, they must be configured as analog inputs. Refer to I/O Lines for details.
  2. After switching inputs to I/O pins, COMPn requires time to settle. Refer to the Electrical Characteristics section for more details.