Reliability-Enhanced ECC-Based Memory Architecture Using In-Field Self-Repair

Gian MAYUGA  Yuta YAMATO  Tomokazu YONEDA  Yasuo SATO  Michiko INOUE  

IEICE TRANSACTIONS on Information and Systems   Vol.E99-D   No.10   pp.2591-2599
Publication Date: 2016/10/01
Publicized: 2016/06/27
Online ISSN: 1745-1361
DOI: 10.1587/transinf.2015EDP7408
Type of Manuscript: PAPER
Category: Dependable Computing
memory repair,  memory reliability,  in-field test and repair,  ECC,  in-field repair strategy,  remapping,  

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Embedded memory is extensively being used in SoCs, and is rapidly growing in size and density. It contributes to SoCs to have greater features, but at the expense of taking up the most area. Due to continuous scaling of nanoscale device technology, large area size memory introduces aging-induced faults and soft errors, which affects reliability. In-field test and repair, as well as ECC, can be used to maintain reliability, and recently, these methods are used together to form a combined approach, wherein uncorrectable words are repaired, while correctable words are left to the ECC. In this paper, we propose a novel in-field repair strategy that repairs uncorrectable words, and possibly correctable words, for an ECC-based memory architecture. It executes an adaptive reconfiguration method that ensures 'fresh' memory words are always used until spare words run out. Experimental results demonstrate that our strategy enhances reliability, and the area overhead contribution is small.