The DFFE primitive allows you to specify a D-type
flipflop with clock enable.
Note: When the ENA (clock enable) input is high, the flipflop passes a
signal from D to Q. When the ENA
input is low, the state of Q is maintained, regardless of the
D input.
For devices that do not support clock enable, logic synthesis
generates logic equations representing flipflops with clock
enables. These logic equations correctly emulate the logic
specified in the project.
Note: For information about Quartus® Prime Standard Edition primitive instantiation, go to Using a Quartus® Prime Standard Edition
Logic Function.