Sign-Magnitude SC: Getting 10X Accuracy for Free in Stochastic Computing for Deep Neural Networks

Stochastic computing (SC) is a promising computing paradigm for applications with low precision requirement, stringent cost and power restriction. One known problem with SC, however, is the low accuracy especially with multiplication. In this paper we propose a simple, yet very effective solution to the low-accuracy SC-multiplication problem, which is critical in many applications such as deep neural networks (DNNs). Our solution is based on an old concept of sign-magnitude, which, when applied to SC, has unique advantages. Our experimental results using multiple DNN applications demonstrate that our technique can improve the efficiency of SC-based DNNs by about 32X in terms of latency over using bipolar SC, with very little area overhead (about 1%).