Streaming Accuracy: Characterizing Early Termination in Stochastic Computing

Stochastic computing has garnered interest in the research community due to its ability to implement complicated compute with very small area footprints, at the cost of some accuracy and higher latency. With its unique tradeoffs between area, accuracy and latency, one commonly used technique to minimize area and latency is to early-terminate computation. Given this, it is useful to be able to measure and characterize how amenable a bitstream is to early termination. We present Streaming Accuracy, a metric that measures how far a bitstream is from its most early-terminable form. We show that it overcomes limitations of prior studies, and we characterize the design space for building stochastic circuits with early termination. We then propose a new hardware bitstream generator that produces bitstreams with optimal streaming accuracy.