Synchronous Counter Missing Carry Term Debug
A 3-bit synchronous up counter tracks elapsed clock cycles and is widely used in digital timing applications.
Expected behavior:
When Enable is high, the outputs Q2, Q1, and Q0 must increment sequentially from binary 0 to 7 and wrap around to 0.
| Enable | Q2 | Q1 | Q0 | Decimal | |----------|------|------|------|---------| | 1 | 0 | 0 | 0 | 0 | | 1 | 0 | 0 | 1 | 1 | | 1 | 0 | 1 | 0 | 2 | | 1 | 0 | 1 | 1 | 3 | | 1 | 1 | 0 | 0 | 4 | | 1 | 1 | 0 | 1 | 5 | | 1 | 1 | 1 | 0 | 6 | | 1 | 1 | 1 | 1 | 7 |
Simulation shows the observed count sequence is 0, 1, 2, 3, 4, 5, 4, 5, repeating the last two states indefinitely. The upper bits are toggling at the wrong period. Inspect the circuit and correct the fault.
Constraints
- Do not modify the flip-flops or the clock network.
- Modify only the combinational logic driving the flip-flop inputs to restore the correct count sequence.
Topics
Solve this problem
Place the gates, wire them up and watch the signals settle. Every submission runs on the same simulation engine that grades it.
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