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Codiode/Problems/Combinational Logic

Debug Combinational: Swapped Logic Gates

EasyLogic CircuitDebug

A majority voter circuit ensures fault tolerance in redundant systems by outputting 1 only when at least two of its three inputs are 1.

Expected behavior:

| A | B | C | Y | |-----|-----|-----|-----| | 0 | 0 | 0 | 0 | | 0 | 0 | 1 | 0 | | 0 | 1 | 0 | 0 | | 0 | 1 | 1 | 1 | | 1 | 0 | 0 | 0 | | 1 | 0 | 1 | 1 | | 1 | 1 | 0 | 1 | | 1 | 1 | 1 | 1 |

Simulation shows Y = 0 for input A=1, B=1, C=0 and Y = 1 for input A=0, B=0, C=0. The outputs for these test cases are incorrect. Inspect the circuit and correct the fault.

Constraints

  • Replace only the single faulty component.
  • Do not add new gates or alter the fundamental wiring architecture of the circuit.

Topics

logic-gatescombinational-logicdebuggingfault-testing

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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