OCEAN: An On-Chip Incremental-Learning Enhanced Artificial Neural Network Processor With Multiple Gated-Recurrent-Unit Accelerators

Abstract

This paper presents OCEAN: an artificial neural network processor designed for accelerating gated-recurrent-unit (GRU) inference and on-chip incremental learning for sequential modeling. Implemented in 65-nm CMOS with silicon area of $2.9 \times 3.5\,\,\mathrm {mm}^{2}$ , the OCEAN processor features a 32-bit reduced instruction set computing core, 64-KB on-chip SRAM, and eight 16-bit four-cell GRU accelerators for inference and gradient computation. Each GRU accelerator is optimized and enhanced for efficient gradient computation. The processor is measured to consume 155 mW at the peak clock rate of 400 MHz and the supply of 1.2 V or 6.6 mW at 20 MHz/0.8 V. Both inference and on-chip incremental learning are accomplished on well-known AI tasks such as handwritten digit recognition, semantic natural language processing, and biomedical waveform-based seizure detection.