Input Blanking

Input blanking functionality is masking out the input events for a programmable time in a selectable part of the TCD cycle. Input blanking can be used to mask out 'false' input events that are triggered right after changes on the outputs.

To enable input blanking, write 0x1 to the Delay Select bit field in the Delay Control register (DLYSEL in TCDn.DLYCTRL). The trigger source is selected by the Delay Trigger bit field (DLYTRIG in TCDn.DLYCTRL).

Input blanking uses the Delay clock: after a trigger, a counter is counting up until the Delay Value (DLYVAL in TCDn.DLYVAL) is reached before input blanking is turned OFF. The TCD delay clock is a prescaled version of the Synchronization clock. The division factor is set by the Delay Prescaler bit field in the Delay Control register (DLYPRESC in TCDn.DLYCTRL). The duration of the input blanking is given by:

tBLANK=DLYPRESC_division_factor×DLYVALfCLK_TCD_SYNC

Input blanking is using the same logic as the programmable output event. For this reason, it is not possible to use both at the same time.