| 摘要 |
PURPOSE:To obtain an input probability effective to detection of an internal unknown fault of a testing circuit, by discriminating the difference between the output probability of the testing circuit and that of a digital circuit. CONSTITUTION:Inputs of a testing circuit 2 and those of a digital circuit 3 are connected in parallel, and a signal of an input probability (x) is applied form a pattern generating part 1 to each input, and ''0'' degeneration and ''1'' degeneration are performed in each input of the testing circuit 2, and a minimum output difference out of differences between output probabilities of circuits 2 and 3 is obtained in a discriminating part 4, and the input probability (x) of circuits 2 and 3 is changed in this state in accordance with the relation between the minimum output difference and a set output difference. Thus, DELTAx is added to or subtracted from the input probability (x) while performing ''0'' degeneration and ''1'' degeneration in the input probability of each input of the circuit 2 until the minimum output difference is larger than the set output difference, and a value of the input probability where a fault of the circuit 2 can be detected is obtained. |
