D Flip Flop is primarily meant to provide delay as the output of this Flip Flop is same as the input. D Flip Flop can easily be made by using a SR Flip Flop or JK Flip Flop. But sometimes designers may be required to design other Flip Flops by using D Flip Flop. Here we discuss how to convert a D Flip Flop into JK and SR Flip Flops.
The first thing that needs to be done for converting one Flip Flop into another is to draw the truth table for both the Flip Flops. The next step is to create the equivalent K-Maps for the required outputs.
JK Flip Flop using D Flip Flop
To create a JK Flip Flop using D Flip Flop, first the conversion table is created as shown:
| J | K | Qn | Qn+1 | D |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 1 | 1 |
| 0 | 1 | 0 | 0 | 0 |
| 0 | 1 | 1 | 0 | 0 |
| 1 | 0 | 0 | 1 | 1 |
| 1 | 0 | 1 | 1 | 1 |
| 1 | 1 | 0 | 1 | 1 |
| 1 | 1 | 1 | 0 | 0 |
X—Dont care
The K-Map for the required input-output relation is:
So, a logic diagram can be developed on the basis of these relations as:
SR Flip Flop using D Flip Flop
To create a SR Flip Flop using D Flip Flop, first the conversion table is created as shown:
| S | R | Q n | Q n+1 | D |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 |
| 0 | 0 | 1 | 1 | 1 |
| 0 | 1 | 0 | 0 | 0 |
| 0 | 1 | 1 | 0 | 0 |
| 1 | 0 | 0 | 1 | 1 |
| 1 | 0 | 1 | 1 | 1 |
| 1 | 1 | X | X | X |
| 1 | 1 | X | X | X |
X—Dont care
Q and Qn+1 are invalid for S=R=1.
The K-Map for the required input-output relation is:
Its logic diagram can be given as:
