TORRES: A Resource-Efficient Inference Processor for Binary Convolutional Neural Networks Based on Locality-Aware Operation Skipping

Abstract

A binary convolutional neural network (BCNN) is a neural network promising to realize analysis of visual imagery in low-cost resource-limited devices. This study presents an efficient inference processor for BCNNs, named TORRES. TORRES performs inference efficiently, skipping operations based on the spatial locality inherent in feature maps. The training process is regularized with the objective of skipping more operations. The microarchitecture is designed to skip operations and generate addresses efficiently with low resource usage. A prototype inference system based on TORRES has been implemented in a 28 nm field-programmable gate array, and its functionality has been verified for practical inference tasks. Implemented with 2.31 K LUTs, TORRES achieves the inference speed of 291.2 GOP/s, exhibiting the resource efficiency of 126.06 MOP/s/LUT. The resource efficiency of TORRES is 1.45 times higher than that of the state-of-the-art work.