Circuit Topology and Synthesis Flow Co-Design for the Development of Computational ReRAM

Emerging memory technologies will play a decisive role in the quest for more energy-efficient computing systems. Computational ReRAM structures based on resistive switching devices (memristors) have been explored for in-memory computations using the resistance of ReRAM cells for storage and for logic I/O representation. Such approach presents three major challenges: the support for a memristor-oriented logic style, the ad-hoc design of memory array driving circuitry for memory and logic operations, and the development of dedicated synthesis tools to instruct the multi-level operations required for the execution of an arbitrary logic function in memory. This work contributes towards the development of an automated design flow for ReRAM-based computational memories, highlighting some important HW-SW co-design considerations. We briefly present a case study concerning a synthesis flow for a nonstateful logic style and the co-design of the underlying 1T1R crossbar array driving circuit. The prototype of the synthesis flow is based on the ABC tool and the Z3 solver. It executes fast owing to the level-by-level mapping of logic gates. Moreover, it delivers a mapping that minimizes the logic function latency through parallel logic operations, while also using the less possible ReRAM cells.