Design And Implementation Of Advanced ATPG Generating Compressible Test Vector

Abstract

To test the functioning of IC in today's era, Automatic Test Pattern Generator(ATPG) is becoming increasingly important as designs become more complicated.Keeping the structural fault coverage high while maintaining an acceptable designoverhead is critical, it is important to achieve a high level of reliability with minimumcost and time. ATPG is benecial in many ways. First, it can reduce the test timefor a large circuit. In addition, ATPG can provide at speed, in system testing of theCircuit-Under-Test (CUT). This is a crucial component for the quality of testing.Single stuck at fault model is considered through out this project. Considering singlestuck at fault, the fault list becomes lengthy as circuit -under- test (CUT) has largenumber of nets, to reduce the number of faults, fault equivalence method is used.Testability measures like controllability- 0, controllability -1 and Observability areconsidered to nd how complicated is to test internal nodes. Testability measures arecontrollability and observability. Controllability guides the test generation algorithmswhile setting a value to primary input (PI) in line justication problem. Actual gen-eration of test vector for every fault involves line activation step \line justication"and error propagation up to primary output .The codes are developed using C++language for 2-fanin-fanout , and upto 10 fanin-fanout gates. The all programs aregeneric and can be used for any combinational circuit upto 10-fanin-fanout gate.An ecient and simple technique for test pattern generation is necessary with theintension of reducing number of faults and with use of testability measures along withadvanced algorithm. This algorithm must be simple. In this project combinationalATPG is developed based on testability measures, FAN algorithm with reduced faultdirectory using fault equivalence. The proposed algorithm-modied FAN for genera-tion of test vectors is simple and can be used as an open source for academicians.The test vectors generated by advanced ATPG is compressed .The compression pro-gram is developed using C++ language.