38.5.6.3 Dedicated Digital Comparator

The ADC module has a dedicated Digital Comparator that can alert the application to the capture and conversion of input signals that match predefined criterion(s). When an input conversion produces a “hit” the flag INTFLAG.CMPHIT is set, which can optionally fire the interrupt if INTENSET.CMPHIT is set. The index, k, of the input channel that produce the “hit” is identified in the INTENSET.CMPINTID[3:0] field.

The Digital Comparator must be enabled by setting CMPCTRL.CMPEN. Only those input channels that have the associated CHNCMPENk bit set are included in the comparator scans.

The CMPCTRL register supports these comparisons directly:

• bit 29 IEHIHI: Enable Comparison - High Limit, Active High:

  Setting this bit enables comparison events ADCMPHI ≤ ADC value

• bit 28 IEHILO: Enable Comparison - High Limit, Active Low:

  Setting this bit enables comparison events ADC value < ADCMPHI

• bit 15 IEBTWN: Enable Comparison - Active Between Limits:

  Setting this bit enables comparison events ADCMPLO ≤ ADC Value < ADCMPHI

• bit 14 IELOHI: Enable Comparison - Low Limit, Active High:

  Setting this bit enables comparison events ADCMPLO ≤ ADC Value

• bit 13 IELOLO: Enable Comparison - Low Limit, Active Low:

  Setting this bit enables comparison events ADC Value < ADCMPLO

Since setting more than one of the IE* bits produces a condition that is the and of all conditions enabled, it is not a recommended configuration.