Ultra Low Energy Analog Image Processing Using Spin Neurons

TL;DR

This paper introduces an ultra low energy analog image processing architecture using spin neurons, achieving significant energy reduction compared to traditional CMOS methods, and is the first to apply nano magnets in this context.

Contribution

Proposes a novel spin neuron-based analog image processing system that drastically reduces energy consumption and demonstrates its effectiveness through physics-based simulations.

Findings

Over two orders of magnitude energy reduction compared to CMOS

Successful simulation of feature extraction and image processing tasks

First application of nano magnets in analog signal processing

Abstract

In this work we present an ultra low energy, 'on-sensor' image processing architecture, based on cellular array of spin based neurons. The 'neuron' constitutes of a lateral spin valve (LSV) with multiple input magnets, connected to an output magnet, using metal channels. The low resistance, magneto-metallic neurons operate at a small terminal voltage of ~20mV, while performing analog computation upon photo sensor inputs. The static current-flow across the device terminals is limited to small periods, corresponding to magnet switching time, and, is determined by a low duty-cycle system-clock. Thus, the energy-cost of analog-mode processing, inevitable in most image sensing applications, is reduced and made comparable to that of dynamic and leakage power consumption in peripheral CMOS units. Performance of the proposed architecture for some common image sensing and processing applications like, feature extraction, halftone compression and digitization, have been obtained through physics based device simulation framework, coupled with SPICE. Results indicate that the proposed design scheme can achieve more than two orders of magnitude reduction in computation energy, as compared to the state of art CMOS designs, that are based on conventional mixed-signal image acquisition and processing schemes. To the best of authors' knowledge, this is the first work where application of nano magnets (in LSV's) in analog signal processing has been proposed.