Hamming Distance Tolerant Content-Addressable Memory (HD-CAM) for Approximate Matching Applications

TL;DR

HD-CAM is a new energy-efficient content-addressable memory that uses charge redistribution for approximate matching, suitable for genomic applications like virus detection, and robust against process variations.

Contribution

It introduces a novel Hamming distance tolerant CAM design that improves energy efficiency and robustness for approximate search applications.

Findings

Supports wide range of mismatch thresholds

Operates reliably under process variations

Suitable for genomic surveillance applications

Abstract

We propose a novel Hamming distance tolerant content-addressable memory (HD-CAM) for energy-efficient in memory approximate matching applications. HD-CAM implements approximate search using matchline charge redistribution rather than its rise or fall time, frequently employed in state of-the-art solutions. HD-CAM was designed in a 65 nm 1.2 V CMOS technology and evaluated through extensive Monte Carlo simulations. Our analysis shows that HD-CAM supports robust operation under significant process variations and changes in the design parameters, enabling a wide range of mismatch threshold (tolerable Hamming distance) levels and pattern lengths. HD-CAM was functionally evaluated for virus DNA classification, which makes HD-CAM suitable for hardware acceleration of genomic surveillance of viral outbreaks such as Covid-19 pandemics.