ECC Caching Techniques for Protecting NAND Flash Memories

Shyue Kung Lu, Zeng Long Tsai, Chun Lung Hsu, Chi Tien Sun

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Due to the rapid technology scaling and increasing program/erase cycling, the raw bit error rate (RBER) in NAND flash memory keeps increasing rapidly. Conventional error correction codes (ECCs) with stronger protection capability are usually equipped for all flash pages as a solution to maintain the mandatory yield and reliability levels. However, the growth of RBER induced by increasing P/E cycles will lead to uneven distribution of errors. Applying uniform ECC protection capability for all flash pages might incur unnecessary hardware and latency overhead. Moreover, the overlong ECC check bits might be stored in two different flash pages. Therefore, two flash reads are required to retrieve a codeword. In this paper, ECC caching (E3C) techniques are proposed to cure these drawbacks of conventional uniform protection techniques. The main idea is to upgrade the ECC protection levels for flash pages when their correction slack is below the specified threshold. According to experimental results, we can enhance the reliability of flash memories significantly with negligible hardware cost.

Original languageEnglish
Title of host publicationProceedings - 2020 IEEE International Test Conference in Asia, ITC-Asia 2020
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages47-52
Number of pages6
ISBN (Electronic)9781728189444
DOIs
StatePublished - Sep 2020
Event4th IEEE International Test Conference in Asia, ITC-Asia 2020 - Taipei, Taiwan
Duration: 23 Sep 202025 Sep 2020

Publication series

NameProceedings - 2020 IEEE International Test Conference in Asia, ITC-Asia 2020

Conference

Conference4th IEEE International Test Conference in Asia, ITC-Asia 2020
Country/TerritoryTaiwan
CityTaipei
Period23/09/2025/09/20

Fingerprint

Dive into the research topics of 'ECC Caching Techniques for Protecting NAND Flash Memories'. Together they form a unique fingerprint.

Cite this