This work introduces a spike-based wearable analytics system utilizing Spiking Neural Networks (SNNs) deployed on an In-memory Computing engine based on RRAM crossbars, which are known for their compactness and energy-efficiency. Given the hardware constraints and noise characteristics of the underlying RRAM crossbars, we propose online adaptation of pre-trained SNNs in real-time using Direct Feedback Alignment (DFA) against traditional backpropagation (BP). Direct Feedback Alignment (DFA) learning, that allows layer-parallel gradient computations, acts as a fast, energy & area-efficient method for online adaptation of SNNs on RRAM crossbars, unleashing better algorithmic performance against those adapted using BP. Through extensive simulations using our in-house hardware evaluation engine called DFA_Sim, we find that DFA achieves upto 64.1% lower energy consumption, 10.1% lower area overhead, and a 2.1x reduction in latency compared to BP, while delivering upto 7.55% higher inference accuracy on human activity recognition (HAR) tasks.
@article{arxiv.2502.06736,
title = {Low-power Spike-based Wearable Analytics on RRAM Crossbars},
author = {Abhiroop Bhattacharjee and Jinquan Shi and Wei-Chen Chen and Xinxin Wang and Priyadarshini Panda},
journal= {arXiv preprint arXiv:2502.06736},
year = {2025}
}
Comments
Accepted in 2025 IEEE International Symposium on Circuits and Systems (ISCAS)