Comparator Negative Input Selection

The NCH bits direct an analog input pin and internal reference voltage or analog ground to the inverting input of the comparator:

NCH Negative Input Sources
111 AVSS
110 FVR_Buffer2
101 CxNCH not connected
100 CxNCH not connected
011 CxIN3-
010 CxIN2-
001 CxIN1-
000 CxIN0-
Important: To use CxINy- pins as analog input, the appropriate bits must be set in the ANSEL register and the corresponding TRIS bits must also be set to disable the output drivers.