A Low-Power DNN Accelerator Enabled by a Novel Staircase RRAM Array

Enhancing the ubiquitous sensors and connected devices with computational abilities to realize visions of the Internet of Things (IoT) requires the development of robust, compact, and low-power deep neural network accelerators. Analog in-memory matrix-matrix multiplications enabled by emerging memories can significantly reduce the accelerator energy budget while resulting in compact accelerators. In this article, we design a hardware-aware deep neural network (DNN) accelerator that combines a planar-staircase resistive random access memory (RRAM) array with a variation-tolerant in-memory compute methodology to enhance the peak power efficiency by 5.64× and area efficiency by 4.7× over state-of-the-art DNN accelerators. Pulse application at the bottom electrodes of the staircase array generates a concurrent input shift, which eliminates the input unfolding, and regeneration required for convolution execution within typical crossbar arrays. Our in-memory compute method operates in charge domain and facilitates high-accuracy floating-point computations with low RRAM states, device requirement. This work provides a path toward fast hardware accelerators that use low power and low area.