Method of and apparatus for fault detection in digital circuits by comparison of test signals applied to a test circuit and a faultless reference circuit

摘要

A fault detection system for electronic circuits is disclosed which comprises a detection circuit in which the crosscorrelation values between the test signal sequence, input to a circuit to be tested, and the output signal sequence from it, with no delay and with delays made in steps to a predetermined time interveral either in the test input signal or in the output sequence, are counted, a reference circuit in which the crosscorrelation values between the test signal sequence input to a faultless reference circuit and the output signal sequence from it, are counted, and a comparator for comparing the crosscorrelation values from both the detection and reference circuit. In one preferred embodiment, one or more of the conventional data compression methods selected from the group of the one's counting, transistion counting, auto-correlation, and C. R. C. methods are incorporated for operation in conjunction with the system.