Edge Detector

The edge detector can be used to generate a pulse when detecting a rising edge on its input. To detect a falling edge, the TRUTH table can be programmed to provide an inverted output.

The edge detector is enabled by writing ‘1’ to the Edge Detection (EDGEDET) bit in the LUTn Control A (CCL.LUTnCTRLA) register. To avoid unpredictable behavior, a valid filter option must be enabled.

The edge detection is disabled by writing a ‘0’ to EDGEDET in CCL.LUTnCTRLA. After disabling an LUT, the corresponding internal edge detector logic is cleared one clock cycle later.

Figure 1. Edge Detector