Negative Feedback Training: A Novel Concept to Improve Robustness of NVCiM DNN Accelerators

Compute-in-Memory (CiM) utilizing non-volatile memory (NVM) devices presents a highly promising and efficient approach for accelerating deep neural networks (DNNs). By concurrently storing network weights and performing matrix operations within the same crossbar structure, CiM accelerators offer DNN inference acceleration with minimal area requirements and exceptional energy efficiency. However, the stochasticity and intrinsic variations of NVM devices often lead to performance degradation, such as reduced classification accuracy, compared to expected outcomes. Although several methods have been proposed to mitigate device variation and enhance robustness, most of them rely on overall modulation and lack constraints on the training process. Drawing inspiration from the negative feedback mechanism, we introduce a novel training approach that uses a multi-exit mechanism as negative feedback to enhance the performance of DNN models in the presence of device variation. Our negative feedback training method surpasses state-of-the-art techniques by achieving an impressive improvement of up to 12.49% in addressing DNN robustness against device variation.