| Excitation tables: D flip-flop | ||||||||||||||
| Characteristic tables define the behavior of flip-flops: | ||||||||||||||
| D flip-flop | T flip-flop | |||||||||||||
| D | Q | Q+ | Operation | T | Q | Q+ | Operation | |||||||
| 0 | 0 | 0 | reset | 0 | 0 | 0 | hold | |||||||
| 0 | 1 | 0 | reset | 0 | 1 | 1 | hold | |||||||
| 1 | 0 | 1 | set | 1 | 0 | 1 | toggle | |||||||
| 1 | 1 | 1 | set | 1 | 1 | 0 | toggle | |||||||
| Excitation table: Shows what input is necessary to generate a given output | ||||||||||||||
| Different view of flip-flop operation | ||||||||||||||
| Inputs: Q, Q+ | ||||||||||||||
| Output: control (D or T) | ||||||||||||||
| Q | Q+ | D | ||||||||||||
| 0 | 0 | 0 | How do we get a new state of 0 with a D flip-flop? | |||||||||||
| 0 | 1 | 1 | Input 0 | |||||||||||
| 1 | 0 | 0 | How do we get a new state of 1 with a D flip-flop? | |||||||||||
| 1 | 1 | 1 | Input 1 | |||||||||||
| Notice that column D is a copy of column Q+, | ||||||||||||||
| because the new state is the same as the control input D | ||||||||||||||