Flash Memory Block Wear Management via Section Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic storage devices using erase-limited memory devices, such as NAND flash memory, face limitations due to the finite number of erase cycles, leading to bit errors and eventual data unreliability, with existing solutions like wear-leveling and write-in-place techniques either spreading erase cycles or increasing them in control blocks.
Innovation Solution
The implementation of a method that initializes and manages 'flop' sections across multiple erase-limited memory blocks, mapping primary addresses to sets of flash blocks to distribute write operations and minimize erase cycles by using a mapping table and section selection sequence to optimize data storage and retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wear-leveling is used to spread out erase cycles, then data reliability is maintained, but erase cycles are not actually reduced
Solution Approach 1:
The flash memory device is divided into multiple flash blocks, and each flash block is further divided into multiple sections. This segmentation allows the system to manage erase cycles at the section level rather than the block level, enabling more granular control over wear distribution and extending overall device lifespan by keeping only portions of blocks active at any given time.
2Productivity
If write-in-place technique is employed, then write operations are optimized, but erase cycles increase in embodiments that use control blocks
Solution Approach 1:
The invention extracts the control information (section valid indicators, mapping data) from the main data storage area into separate control structures stored in other flash blocks. This separation allows write-in-place operations to proceed efficiently in data blocks without requiring frequent erasure of control blocks, as the control information is updated in a dedicated area that can be managed independently.
Solution Approach 2:
The patent introduces mapping tables and section valid indicators as intermediary structures that mediate between the host system and the physical flash blocks. These intermediaries allow the system to track which sections are valid and where data is stored without requiring erasure of control information, enabling write-in-place operations to proceed without increasing erase cycles in control blocks.
3Productivity
If flash blocks are frequently erased and rewritten, then storage capacity is maintained, but the flash block eventually reaches its erase cycle limit and data reliability deteriorates
Solution Approach 1:
The system implements a section-based wear leveling strategy where, upon detecting that a flash block has reached its erase cycle limit, the system discards that block from active use and recovers its storage capacity by redistributing data to other sections. The invalidated block is marked with a section valid indicator, and data is migrated to alternative sections, allowing the original block to be reused after erasure while maintaining overall data reliability.
Data Source
AI summary
A solution for reducing erase cycles in an electronic storage device that uses at least one erase-limited memory device is disclosed.