Scalable stochastic number duplicators for accuracy-flexible arithmetic circuit design

Stochastic computing is a computation method which can implement arithmetic operations by simple logic circuits. Stochastic numbers are used in this method, whose values are defined by their bit streams' appearance rates of 1's. As a nature of stochastic computing, changing the length of the input stochastic numbers will change the whole circuit's accuracy. However, in some implementations with re-convergence paths, the circuit itself will cause errors, i.e., the length of the input stochastic numbers does not change that circuit's accuracy. This paper proposes a stochastic number duplicator whose outputs differ every time and are all independent. This stochastic number duplicator has a scalable structure by changing the numbers of flip-flops for bit re-arrangement. From the experimental evaluations and discussions, we clarify that the proposed stochastic number duplicator enables accuracy-flexible circuits.