Test Pattern Generator for MV-Based QCA Combinational Circuit Targeting MMC Fault Models

Abstract

Quantum-dot-Cellular Automata (QCA) is emerging as one of the alternatives for Integrated Circuit Technology considering the scaling limitations of current Complementary Metal Oxide Semiconductor (CMOS) technology. Being at molecular scale, defects are more likely to occur in QCA devices. Therefore, the substantial development of QCA-oriented defects, its corresponding fault models and test generation is required. This paper addresses the fault model caused by multiple missing cells defect and test generation for these faults for QCA circuits. We have shown that the single missing cell considerations are not enough. Correspondingly, in this paper, testing properties for the detection of fault caused by multiple missing cell defects in QCA devices mainly Majority Voter (MV) are proposed. Even though there are many advanced ATPGs available for CMOS technology, to demonstrate very special MV-based properties with reference to the test pattern generation process and to open the path for advanced combinational and sequential ATPGs specific to MV-based QCA circuits, the extension of basic Automatic Test Pattern Generator is proposed here. The proposed test generation algorithm is guided by the extended Sandia Controllability Observability Analysis Program (SCOAP) testability measures especially for QCA logic primitives.