Machine Learning Algorithm Co-Design for a 40 nm RRAM Analog Compute-in-Memory Accelerator

Resistive Random-Access Memory (RRAM)-based analog compute-in-memory (CIM) chips can be used to accelerate deep neural network (DNN) inference in low power, resource-constrained edge-devices. In this work, we present software algorithm co-design techniques to optimize DNN inference on RRAM-based CIM accelerators for a hand-written digit recognition workload. Our approach involves three key steps: 1) an integer-based training framework that optimizes raw DNN output for low bit-width networks; 2) a row rename step that leverages low weight variance in low-precision networks to reduce network storage requirements; and 3) a row reorder step that leverages the spatial nature of sparsity-aware input control to reduce the effect of analog noise on error rate. We apply our techniques to train a LeNet-5 model using 1-bit weights and 2-bit activations to 96.66% accuracy on the MNIST dataset, reduce area of the final fully connected layer by 45.24%, and reduce the impact of analog noise in the final layer on inference accuracy by 5.6%.