Aging Aware Retraining for Memristor-based Neuromorphic Computing

Wenwen Ye, Grace Li Zhang, Bing Li, Ulf Schlichtmann, Cheng Zhuo, Xunzhao Yin

Abstract: Memristor-based crossbars, which can achieve 1-2 orders of magnitude energy efficiency improvement over digital machines, have been introduced to accelerate the neural networks of machine learning tasks. Due to the high voltage pulses repeatedly applied onto memristors during programming and online tuning, the effective resistance ranges of the memristors actually decrease as a result of aging, which eventually impair the inference accuracy of the neural network running on the memristor-based crossbar. In this paper, we propose an algorithm-hardware co-design framework combining aging aware retraining and gradient sparsification to mitigate the impact of aging and extend the lifetime of the crossbar. Experimental results show that the proposed method can effectively increase the inference accuracy by up to 16% even with severe aging, while the crossbar lifetime can be extended by up to $2.7\times$.