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Codiode/Problems/Memory Design

Debugging Read During Write Collision

MediumLogic CircuitDebug

A memory read controller handles outputting stored data during read operations and must guarantee read-first behavior during simultaneous read and write cycles.

Expected behavior:

| RE | WE | WD | MemData | ReadOut | |------|------|------|-----------|-----------| | 0 | 0 | 0 | 1 | 0 | | 1 | 0 | 0 | 1 | 1 | | 1 | 0 | 1 | 0 | 0 | | 1 | 1 | 1 | 0 | 0 | | 1 | 1 | 0 | 1 | 1 |

Simulation shows ReadOut = 1 for inputs RE=1, WE=1, WD=1, MemData=0. The read output is incorrectly showing the new write data instead of the old stored data. Inspect the circuit and correct the fault.

Constraints

  • The circuit must use purely combinational logic.
  • ReadOut must be driven to 0 when RE is 0.

Topics

MemoryCombinational LogicDebug

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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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