1.1.5 Internal Events Input (EVENT)

Asynchronous events from Event System can be used as input selection. One event input line is available for each LUT and can be selected on each LUT input. Internal events input is selected by writing the Input y Source Selection bit group in the LUT Control x register (LUTCTRLx.INSELy) to 0x3. Before enabling the event selection, the Event System must be configured.

The CCL includes an edge detector which generates an internal strobe when the event rising edge is detected. The strobe duration is one GCLK_CCL clock cycle. To ensure the proper operation, the following steps must be followed:
  • Enable the GCLK_CCL clock
  • Configure Event System to route the desired event asynchronously
  • Set the Inverted Event Input Enable bit in LUT Control register (LUTCTRLx.INVEI = 1) if a strobe must be generated on the event input falling edge
  • Set the Event Input Enable bit in LUT Control register (LUTCTRLx.LUTEI = 1)