Analisi di un contatore asincrono up-down
1) Schematic
2) Timing diagram
3) The circuit is. an asynchronous up and down counter. It is a circuit that do not have inputs (but only the reset one), and that works in the same sequence in a close continue cycle.
4) Truth table of the combinational network:
| Q2 |
Q1 |
Q0 |
C2 | C1 | C0 | Val |
| 1 | 1 | 1 | 0 | 0 | 0 | 0 |
| 1 | 1 | 0 | 0 | 0 | 1 | 1 |
| 1 | 0 | 1 | 0 | 1 | 0 | 2 |
| 1 | 0 | 0 | 0 | 1 | 1 | 3 |
| 0 | 1 | 1 | 1 | 0 | 0 | 4 |
| 0 | 1 | 0 | 1 | 0 | 1 | 5 |
| 0 | 0 | 1 | 1 | 1 | 0 | 6 |
| 0 | 0 | 0 | 1 | 1 | 1 | 7 |
5) Timing diagram (showing Q2, Q1, Q0, C2, C1, C0 outputs)