Department of Information and Communication Engineering, Cheongju 28644, South Korea.
iDataMap Corporation, Eastwood, South Australia 5063, Australia.
J Nanosci Nanotechnol. 2021 Mar 1;21(3):1833-1844. doi: 10.1166/jnn.2021.18910.
Nano memristor crossbar arrays, which can represent analog signals with smaller silicon areas, are popularly used to describe the node weights of the neural networks. The crossbar arrays provide high computational efficiency, as they can perform additions and multiplications at the same time at a cross-point. In this study, we propose a new approach for the memristor crossbar array architecture consisting of multi-weight nano memristors on each cross-point. As the proposed architecture can represent multiple integer-valued weights, it can enhance the precision of the weight coefficients in comparison with the existing memristor-based neural networks. This study presents a Radix-11 nano memristor crossbar array with weighted memristors; it validates the operations of the circuits, which use the arrays through circuit-level simulation. With the proposed Radix-11 approach, it is possible to represent eleven integer-valued weights. In addition, this study presents a neural network designed using the proposed Radix-11 weights, as an example of high-performance AI applications. The neural network implements a speech-keyword detection algorithm, and it was designed on a TensorFlow platform. The implemented keyword detection algorithm can recognize 35 Korean words with an inferencing accuracy of 95.45%, reducing the inferencing accuracy only by 2% when compared to the 97.53% accuracy of the real-valued weight case.
纳米忆阻器交叉阵列,由于其能够以较小的硅面积表示模拟信号,因此被广泛用于描述神经网络的节点权重。交叉阵列提供了较高的计算效率,因为它们可以在交叉点同时执行加法和乘法。在这项研究中,我们提出了一种由每个交叉点上的多权重纳米忆阻器组成的新型忆阻器交叉阵列架构。由于所提出的架构可以表示多个整数值权重,因此与现有的基于忆阻器的神经网络相比,可以提高权重系数的精度。本研究提出了一种具有加权忆阻器的基数-11 纳米忆阻器交叉阵列;通过电路级仿真验证了使用该阵列的电路操作。通过所提出的基数-11 方法,可以表示十一个整数值权重。此外,本研究还提出了一种使用所提出的基数-11 权重设计的神经网络,作为高性能人工智能应用的示例。该神经网络实现了语音关键字检测算法,并在 TensorFlow 平台上进行了设计。实现的关键字检测算法可以识别 35 个韩语单词,推断准确率为 95.45%,与实数权重情况下的 97.53%推断准确率相比,仅降低了 2%。