Automatic Test Pattern Generation Through Boolean Satisfiability for Testing Bridging Faults

Automatic test pattern generation (ATPG) is one of the important issues in testing digital circuits. Due to considerable advances made in the past two decades, the ATPG algorithms that are based on Boolean satisfiability have become an integral part of the digital circuits. In this paper, a new method for ATPG for testing bridging faults is introduced. First of all, the application of Boolean satisfiability to circuit modeling is explained. Afterwards, a new method of testing the nonfeedback bridging faults in the combinational circuits is proposed based on Boolean satisfiability. In the proposed method, the faulty circuit is obtained by injecting the faulty gate into the main circuit. Afterwards, the final differential circuit is prepared by using the fault-free and the faulty circuits. Finally, using the resulting differential circuit, the testability of the fault is assessed and the input pattern for detecting the fault in the main circuit is derived. The experimental results presented at the end of this paper indicate the effectiveness and usefulness of this method for testing the bridging faults.