A Scalable In-Memory Logic Synthesis Approach Using Memristor Crossbar

Because of their resistive switching properties and ease of controlling the resistive states, memristors have been proposed in nonvolatile storage as well as logic design applications. Memristors can be fabricated in a crossbar and suitable voltages applied to the row and column nanowires to control their states. This makes it possible to move toward new non-von Neumann-type architectures, usually referred to as in-memory computing, where logic operations can be performed directly on the storage fabric. In this paper, a scalable design flow for in-memory computing has been proposed, where a given multioutput logic function is synthesized as a netlist of NOT/NOR gates and then mapped to the crossbar using the Memristor-Aided loGIC (MAGIC) design style. The memristors corresponding to the primary inputs are initialized a priori. Subsequently, the required gate operations are performed by applying suitable row and column voltages in sequence. Two alternate mapping schemes have been analyzed. The switching characteristics of MAGIC NOR gates have been evaluated using circuit simulation under the Cadence Virtuoso environment. Experimental evaluation on ISCAS’85 benchmarks reports the average improvements of 27.7%, 34.6%, and 26.2%, respectively over a recently published work with respect to the number of memristors, number of cycles, and total energy dissipation, respectively. It may be noted that the energy consumption of the gates used in the proposed approach (NOT and NOR) is significantly higher than that using CMOS technology.