3-17
Figure 3-17. —D flip-flop with PR and CLR inputs.
You may also see an inverter at the clock input. In this case, the output will change on the negative-
going transition of the clock pulse.
Q24. What are the inputs to a D FF?
Q25. How long is data delayed by a D FF?
Q26. What condition must occur to have a change in the output of a D FF?
J-K FLIP-FLOP
The J-K FF is the most widely used FF because of its versatility. When properly used it may perform
the function of an R-S, T, or D FF. The standard symbol for the J-K FF is shown in view A of figure 3-18.
