Enhance the Robustness to Time Dependent Variability of ReRAM-Based Neuromorphic Computing Systems with Regularization and 2R Synapse

Time Dependent Variability (TDV) is one of the major concerns in implementing a Neuromorphic Computing System (NCS) with Resistive Random Access Memory (ReRAM). In this work, we propose a variation-distribution aware training algorithm to enhance the robustness of NCS to TDV without incurring extra hardware overhead by leveraging algorithm-level regularization and hardware-level 2R synapse structure. Simulation results on image recognition tasks show that our method improves the system accuracy by up to ∼4% and ∼10% under the worst-case TDV condition for MNIST and CIFAR-10, respectively. Detailed analysis also shows that our method allows the NCS to use synapses with higher resistance than conventional design for the same accuracy requirement, introducing potential energy saving.