Low-Cost High-Accuracy Random Number Source Design for Stochastic Computing via Exploitation of Uniform Spatial Distribution

Stochastic computing (SC) generally suffers from long latency. One solution is to apply proper random number sources (RNSs) to generate the bit streams. However, existing RNS designs either have low accuracy or high hardware cost. To address this drawback, motivated by the fact that a uniform spatial distribution generally leads to high accuracy for an SC circuit, we propose a basic architecture to produce a uniform spatial distribution and a further detailed implementation of it. For the implementation, we further propose a method to optimize its hardware cost and an algorithm following a guiding principle to improve its accuracy. The method for hardware cost optimization allows hardware cost reduction while keeping the accuracy. Our experimental results show that the proposed implementation achieves both high accuracy and low hardware cost. For example, compared to a state-of-the-art stochastic number generator design, our design can reduce hardware cost by over 80%, while achieving higher accuracy