A Fault-Detection System for Digital Integrated Circuits

A system has been developed for the detection of most commonly occurring faults in digital IC's. Such faults consist of either permanent ("stuck-at") logic levels at input or output terminals, or short-circuits between adjacent terminals in a microcircuit. In the test system to be described both input and output terminals are simultaneously analyzed under quasi-optimum test patterns. The input and output test patterns for each circuit of interest are stored in an average of 330 bits of READ-ONLY memory. The present system is capable of testing the logic operation of CMOS and all families of TTL circuits.