Summary
International Workshop on Smart Info-Media Systems in Asia
2021
Session Number:RS1
Session:
Number:RS1-5
ReLU Functions Using Finite State Machines for Stochastic Computing
Kanta Yoshioka, Ichiro Kawashima, Hakaru Tamukoh,
pp.40-45
Publication Date:2021/9/20
Online ISSN:2188-5079
Summary:
This study presents novel ReLU functions-based on stochastic computing (SC-based ReLU). The conventional SC-based ReLU for an addition method using approximate parallel counter (APC), which outputs the sum of multiple inputs every clock cycle works as a ReLU using accumulator. However, this conventional method loses the high fault tolerance, which is one of the advantages of stochastic computing (SC). Therefore, we propose an SC-based ReLU using a finite state machine (FSM) instead of an accumulator for an addition method using a multiplexer (MUX) which determines the outputs stochastically. For example, if an error occurs in the value of the accumulator in the conventional method, all subsequent operations will be wrong. However, in the case of the proposed SC-based ReLU using FSM, even if an error occurs in the current state of the FSM, it quickly returns the correct state of the FSM. Thus, the proposed SC-based ReLU using FSM for MUX is more fault tolerant than the conventional SC-based ReLU using the accumulator. However, the accuracy of the addition methods using MUX is poor because the output is determined stochastically, and a large length of bitstream (BSL) is required for accurate calculation. As the BSL becomes larger, the latency for the calculation increases, decreasing the performance. Therefore, we propose a SC-based ReLU using FSM for APC. The addition method using APC doesn’t require BSL as large as the addition method using MUX to obtain correct calculation results. Compared with the conventional SC-based ReLU using an accumulator for APC, the proposed SC-based ReLU using FSM for APC shows sufficient accuracy even with a small BSL. The proposed SC-based ReLU using FSM has also a high fault tolerance,