There are eight modes of operation for the comparators, shown in Figure 20-1. Bits CM2:CM0 of the CMCON register are used to select these modes to Read MCU dsPIC30F6014 Software. The TRISA register controls the data direction of the comparator pins for each mode.

along with the relationship between the analog input levels and the digital output. When the analog input at VIN+ is less than the analog input VIN-, the output of the comparator is a digital low level. When the analog input at VIN+ is greater than the analog input VIN-, the output of the comparator is a digital high level.

Depending on the comparator operating mode, either an external or internal voltage reference may be used. The analog signal present at VIN- is compared to the signal at VIN+ and the digital output of the comparator is adjusted accordingly.

When external voltage references are used, the comparator module can be configured to have the comparators operate from the same or different reference sources. However, threshold detector applications may require the same reference. The reference signal must be between VSS and VDD and can be applied to either pin of the comparator(s) which will help to Read MCU dsPIC30F6014 Software.

The comparator module also allows the selection of an internally generated voltage reference from the comparator voltage reference module. This module is described in more detail in Section 21.0 “Comparator Voltage Reference Module”. The internal reference is only available in the mode where four inputs are multiplexed to two comparators (CM2:CM0 = 110). In this mode, the internal voltage reference is applied to the VIN+ pin of both comparator.