Defect tolerance in QCA-based PLAs

Defect tolerance will be critical in any system with nano-scale feature sizes. This paper examines some fundamental aspects of defect tolerance for a reconfigurable system based on magnetic quantum-dot cellular automata (MQCA). MQCA performs logical operations and moves data by manipulating the polarizations of nano-scale magnets, has been experimentally demonstrated, and operates at room temperature. We consider how specific defects will impact device functionality. Within this context, we introduce techniques for mapping Boolean logic functions to a defective system architecture (a reconfigurable programmable logic array design for MQCA). Simulation results show that our new mapping techniques can achieve much higher yields than existing techniques for nanowire crossbar PLAs.