In Situ Aging-Aware Error Monitoring Scheme for IMPLY-Based Memristive Computing-in-Memory Systems

Stateful logic through memristor is a promising technology to build Computing-in-Memory (CIM) systems. However, aging-induced degradation of memristors' threshold voltage imposes a major challenge to the reliability and guardbands estimation of memristive CIM systems, especially the Material Implication (IMPLY) logic based CIM systems. In this paper, a novel in-situ aging-aware error monitoring scheme for memristor-based IMPLY logic is proposed. The proposed in-situ error monitoring scheme can achieve faster error detection speed and higher detection accuracy than the straightforward program-verify monitoring scheme. Simulation results under Monte-Carlo simulation show that the proposed monitoring scheme can effectively detect the major operation failures existing in IMPLY logic operations with a detection accuracy up to 99.95%. Moreover, a case study of error monitoring design of 4-bit IMPLY-based adder is carried out. The analysis result exhibits that the proposed in-situ monitoring scheme can achieve 75.2% improvement on the detection speed against the program-verify scheme. Further analysis on a convolution filter in VGG-11 based Binarized Neural Network shows that 74% improvement on the detection speed can also be achieved by using the proposed monitoring scheme, which suggests that the proposed in-situ error monitoring scheme is an efficient solution to improve the reliability of IMPLY-based memristive CIM systems.