Hierarchical Memory Wear Leveling via Migration Association Map
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing memory subsystems face challenges in ensuring consistent wear leveling across memory segments, as intra-segment wear leveling does not guarantee even distribution of wear, and inter-segment wear leveling is not effectively managed, leading to potential memory cell failure and reduced storage capacity over time.
Innovation Solution
A hierarchical memory wear leveling system is introduced, utilizing a mapped translation layer with a segment metadata table for intra-segment wear leveling and a migration association map for inter-segment wear leveling, ensuring seamless address indirection and swapping of managed units across memory segments to maintain consistent wear distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If intra-segment wear leveling is implemented, then wear distribution within a memory segment is improved, but wear distribution across memory segments remains inconsistent
Solution Approach 1:
The memory system is divided into multiple memory segments, each managed independently with its own wear leveling mechanisms. This segmentation allows targeted wear management at the segment level while enabling coordinated inter-segment wear leveling through the migration association map, resolving the contradiction by making wear leveling scope manageable yet comprehensive.
Solution Approach 2:
The patent introduces a new dimension of wear leveling by implementing inter-segment wear leveling through the migration association map, which tracks and manages wear across multiple segments. This extends the traditional intra-segment wear leveling to a multi-dimensional approach, ensuring consistent wear distribution both within and across segments.
2Ease of operation
If memory segments are managed independently, then address management is simplified, but inter-segment wear leveling is not effectively managed
Solution Approach 1:
The migration association map serves as an intermediary data structure that tracks physical addresses across memory segments and enables coordinated wear leveling operations. It maintains the simplicity of independent segment management while providing the mechanism needed for effective inter-segment wear leveling by mapping logical addresses to physical locations across segments.
3Reliability
If wear leveling operations are performed frequently, then wear distribution is improved, but operational overhead increases
Solution Approach 1:
The wear leveling operations are performed periodically based on wear thresholds and migration conditions rather than continuously. The system monitors wear levels and triggers migration operations only when necessary, reducing unnecessary overhead while maintaining consistent wear distribution across memory segments.
Data Source
AI summary
A method for performing wear leveling in a memory subsystem. The method includes adding, in response to a wear-leveling event, a migration association map entry to a migration association map to control copying of a first set of managed units from a first memory segment to a second set of managed units of a second memory segment, wherein adding the migration association map entry includes setting an exchange pointer of the migration association map entry to a value that references an unused managed unit in the first memory segment and copying the first set of managed units to the second set of managed units beginning with a managed unit in the first set of managed units following the managed unit referenced by the exchange pointer of the first segment metadata table entry.