Edge Triggered D flip flop Timing Diagram Whereas Asynchronous Preset can Clear can change the output at any instant of time. Synchronous Preset or Clear means that the change caused by this single to the output can affect the clock pulse here, it is edge triggered to change with the edge of the clock pulse. Edge Triggered D flip flop with Preset and ClearĮdge Triggered D type flip flop can come with Preset and Clear preset and Clear both are different inputs to the Flip Flop both can be synchronous or asynchronous. The edge triggered flip Flop is also called dynamic triggering flip flop.