Design of Stochastic Computing Circuits Using Nanomagnetic Logic

Abstract

We consider the design of stochastic computing (SC) hardware based on spintronic devices. SC offers low-cost implementations of arithmetic operations and high degrees of error tolerance. When compared to charge-based devices, spin-based devices could be lower energy, nonvolatile, etc. However, spin-based devices can be fundamentally more error prone than charge-based devices. The marriage of SC architectures and spin-based devices has the potential to produce information processing systems that are robust, low energy, and nonvolatile. In this paper, we investigate SC hardware comprised of nanomagnetic logic (NML) devices. NML is a “beyond-CMOS” technology that uses bistable magnets to store, process, and move binary information. We introduce new NML circuit structures that exploit unique features of the technology to efficiently realize hardware components required for an SC system (e.g., random number generation). We also benchmark NML-based SC circuits against other implementations, and illustrate how features that are unique to NML (e.g., inherent pipelining) can lead to improved performance. Our results indicate NML SC implementations achieve smaller area footprints with reduced energy and delay when compared to CMOS equivalents.