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

arXiv: https://arxiv.org/abs/2111.09747 · HTML: https://mlsanity.com/paper/2111.09747/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 18 Nov 2021.

## Built on by (most cited first, 2 of 2)

- [ClaPIM: Scalable Sequence CLAssification using Processing-In-Memory](https://mlsanity.com/paper/2302.08284/) (2023)
- [CAMformer: Associative Memory is All You Need](https://mlsanity.com/paper/2511.19740/) (2025)

## Abstract (arXiv)

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.