SWIPE: Enhancing Robustness of ReRAM Crossbars for In-memory Computing

Crossbar-based in-memory architectures have emerged as an attractive platform for energy-efficient realization of deep neural networks (DNNs). A key challenge in such architectures is achieving accurate and efficient writes due to the presence of bitcell conductance variations. In this paper, we propose the Single-Write In-memory Program-vErify (SWIPE) method that achieves high accuracy writes for crossbar-based in-memory architectures at 5×-to-10× lower cost than standard program-verify methods. SWIPE leverages the bit-sliced attribute of crossbar-based in-memory architectures and the statistics of conductance variations to compensate for device non-idealities. Using SWIPE to write into ReRAM crossbar allows for a 2× (CIFAR-10) and 3× (MNIST) increase in storage density with <; 1% loss in DNN accuracy. In particular, SWIPE compensates for 4.8×-to-7.7× higher conductance variations. Furthermore, SWIPE can be augmented with injection-based training methods in order to achieve even greater enhancements in robustness.