Checkpoint Faults are not Sufficient Target Faults for Test Generation

Stuck-at faults on primary inputs and fan-out branches are commonly used as target faults in test generation algorithms for combinational circuits. This correspondence shows that these faults may not constitute an adequate set of target faults. A procedure is presented for selecting a set of target faults with the property that the detection of all detectable faults from this set guarantees the detection of all detectable faults in the circuit.