Optimum Test Set for Bridging Fault Detection in Reversible Circuits

Testing of bridging faults in a reversible circuit is investigated in this paper. The intra-level single bridging fault model is considered here, i.e. any single pair of lines, both lying at the same level of the circuit, may be assumed to have been logically shorted in order to model a defect. For an (n X n) reversible circuit with d levels realized with simple Toffoli gates, the time complexity of the test generation procedure is O(nd² log₂n). A test set of cardinality O(d log₂n) is found to be sufficient for testing all such detectable faults. A minimal test set can also be easily derived by using the concept of test equivalence.