Non-Volatile Memory Endurance Management via Severe Erasure Verification
Solution Overview
Problem
Existing methods for managing the endurance of non-volatile memories fail to effectively utilize the intrinsic variability in endurance capacity across different sectors and applications, leading to inefficient use of memory resources and limited endurance enhancement.
Innovation Solution
A method that employs a combination of sector sparing with advanced erasure verification techniques, including a severe read mode and adaptive erasure time management, to dynamically assess and extend the endurance of each sector without relying on guaranteed endurance values, allowing for real-time optimization of memory usage based on specific application needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional endurance management methods are used, then the guaranteed endurance capacity is maintained, but the actual endurance capacity is not maximized due to ignoring statistical distribution variability
Solution Approach 1:
The patent applies local quality by treating each memory sector individually rather than uniformly. It measures the actual endurance capacity of each sector and applies different management strategies based on local characteristics. Sectors with higher actual endurance than guaranteed are identified and utilized more intensively, while sectors with lower endurance are protected or replaced earlier, optimizing overall memory utilization.
Solution Approach 2:
The patent changes the parameter from guaranteed endurance capacity to actual measured endurance capacity. By introducing endurance measurement and evaluation mechanisms, it dynamically adjusts memory management parameters based on real sector conditions rather than static manufacturer guarantees, enabling more precise and efficient endurance management.
2Reliability
If sector sparing is implemented, then worn sectors are replaced, but additional memory resources are consumed and complexity increases
Solution Approach 1:
The patent applies preliminary action by proactively measuring and evaluating sector endurance before failure occurs. It continuously monitors sector health and identifies worn sectors in advance, allowing for planned replacement or protection strategies rather than reactive management, thereby reducing the need for extensive spare sectors.
Solution Approach 2:
The patent implements feedback mechanisms by measuring actual sector performance and endurance characteristics, then using this information to dynamically adjust memory management decisions. This closed-loop approach optimizes replacement strategies and reduces the number of spare sectors needed compared to open-loop traditional methods.
3Reliability
If wear leveling is applied, then endurance is extended across all sectors, but access performance deteriorates due to additional management overhead
Solution Approach 1:
The patent segments memory management into different categories based on actual sector endurance characteristics. It divides sectors into groups such as high-endurance, medium-endurance, and low-endurance sectors, allowing differentiated access and management strategies. This segmentation enables optimized access paths for different sector types, reducing the performance overhead compared to uniform wear leveling.
Solution Approach 2:
The patent introduces dynamic memory management that adapts to changing sector conditions. Rather than static wear leveling algorithms, it dynamically adjusts management strategies based on real-time sector health measurements and actual usage patterns, optimizing the balance between endurance extension and access performance.
4Reliability
If conservative endurance management is used, then reliability is maintained, but memory capacity utilization is reduced
Solution Approach 1:
The patent changes the management parameter from conservative guaranteed endurance thresholds to actual measured endurance values. By introducing endurance measurement and evaluation, it dynamically adjusts usable capacity limits based on real sector conditions, allowing more aggressive utilization of high-endurance sectors while maintaining reliability through continuous monitoring and adaptive management.
Data Source
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AI summary
The invention relates to a method for managing the endurance of a data storage system provided with a set of sectors endowed with a guaranteed native endurance capacity (G), comprising the steps consisting in: - partitioning said data storage system into a plurality of work sectors, and into a plurality of replacement sectors able to form an endurance reservoir, certain of the work sectors being intended to be replaced by replacement sectors when said work sectors are expended after a certain number of programming and/or erasure cycles; - defining an address management area making it possible to retrieve the location of the replacement sectors assigned to expended work sectors; - determining, sector by sector, whether a current work sector is physically expended, and executing a step of replacing this work sector by a replacement sector, only when said current work sector is declared physically expended. This method of managing endurance is in particular characterized in that in order to measure the expenditure of a sector, automatic reading of the quality of erasure of the memory points of the sector with respect to a severized reading criterion (margin Vref.) is carried out, that is to say one which is more severe than a normal criterion (Normal Vref.).