An MRAM-Based Deep In-Memory Architecture for Deep Neural Networks

This paper presents an MRAM-based deep in-memory architecture (MRAM-DIMA) to efficiently implement multi-bit matrix vector multiplication for deep neural networks using a standard MRAM bitcell array. The MRAM-DIMA achieves an 4.5 × and 70× lower energy and delay, respectively, compared to a conventional digital MRAM architecture. Behavioral models are developed to estimate the impact of circuit non-idealities, including process variations, on the DNN accuracy. An accuracy drop of ≤ 0.5% (≤ 1%) is observed for LeNet-300-100 on the MNIST dataset (a 9-layer CNN on the CIFAR-10 dataset), while tolerating 24% (12%) variation in cell conductance in a commercial 22 nm CMOS-MRAM process.