Title
Bit-flipping Schemes upon MLC Flash: Investigation, Implementation, and Evaluation
Abstract
Multilevel cell (MLC) states with lower threshold voltage endure less cell damage, lower retention error, and less current consumption. Based on these characteristics, it is opportunistic to strengthen MLC flash by introducing bit-flipping that reshapes state proportions on MLC pages. In this paper, we present a holistic study of bit-flipping schemes upon MLC flash in theory and practice. Specifically, we systematically investigate effective bit-flipping schemes and propose four new schemes on manipulating MLC states. We further design a generic implementation framework, named MLC bit-flipping framework, to implement bit-flipping schemes within solid state drives controllers, nicely integrating with existing system-level optimizations to further improve overall performance. The experimental results demonstrate that our proposed bit-flipping schemes standalone can reduce up to 28% cell damages and 53% retention errors. Our circuit-level simulation manifests that the bit-flipping latency on a page is less than 4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> when using 8K logic gates.
Year
DOI
Venue
2019
10.1109/tcad.2018.2818693
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Keywords
Field
DocType
Erbium,Writing,Threshold voltage,Reliability,Degradation,Standards
Logic gate,Latency (engineering),Computer science,Electronic engineering,Current consumption,Threshold voltage,Solid-state
Journal
Volume
Issue
ISSN
38
4
0278-0070
Citations 
PageRank 
References 
0
0.34
0
Authors
3
Name
Order
Citations
PageRank
Wenhui Zhang129243.28
Qiang Cao259357.50
Zhonghai Lu31063100.12