INSPECTING DEVICE FOR DIGITAL CIRCUIT

摘要

PURPOSE:To detect a fault through simple operation in a short time by setting plural input probabilities while applying orthogonal functions according to whether the output statistic of a testing circuit is large or small. CONSTITUTION:A pattern whose propability of logical levels ''1'' and ''0'' is controlled is inputted from a pattern generator 1 to the testing circuit 2 and a decision circuit 3 measures the output statistic of the testing circuit 2. An output comparing means 4 compares the output of the decision circuit 3 when the input probability of the testing circuit 2 is varied and sends the result to an orthogonal vector generating means 5. This vector generating means 5 controls an input probability setting means 6 by an orthogonal function according to the result of the output comparing means 4 and calculates such input probability that the minimum output of the output statistic is maximum. Then, the decision circuit 3 decides whether the testing circuit 2 is normal or not from the input probability.