Memory Controller Word Line Zone Bad Block Management
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Solution Overview
Problem
Current memory systems face challenges in efficiently managing bad blocks in memory devices, leading to data write failures and reduced operational efficiency due to the lack of effective bad block management strategies.
Innovation Solution
A memory system and operation method that group word lines into zones, utilize bitmap information to identify and manage bad word line zones by redirecting data writes to adjacent normal zones, and perform error correction to maintain data integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bad block management is performed at the block level, then data integrity is maintained, but operational efficiency deteriorates due to frequent data relocation
Solution Approach 1:
The patent segments the memory block into multiple word line zones, allowing granular identification and management of bad areas. Instead of treating entire blocks as bad, only specific word line zones containing failed memory cells are marked and managed separately, enabling selective data relocation rather than blanket block management.
Solution Approach 2:
The patent performs preliminary identification and marking of bad word line zones during initial memory characterization or upon detecting failures. By pre-identifying problematic zones and maintaining a bitmap of bad areas, the system prepares replacement zone mappings in advance, reducing the need for frequent data relocation operations during normal operation.
2Reliability
If comprehensive bad block management is implemented, then data write failures are reduced, but device complexity increases due to additional management structures
Solution Approach 1:
The patent extracts bad word line zone identification and management from the overall block management system. By separating the identification, marking, and replacement zone selection functions into distinct components with dedicated data structures (bitmap, replacement zone mapping), the system manages complexity through modular organization while maintaining comprehensive bad block management capabilities.
3Reliability
If data is redirected to adjacent normal zones, then data write operations succeed, but access time increases due to non-sequential access patterns
Solution Approach 1:
The patent applies local quality by selecting replacement zones that are spatially adjacent to or near the bad zones. This localization strategy ensures that replacement data remains close to the original access location, minimizing the impact on access patterns and reducing the time penalty associated with data redirection while still achieving successful writes.
Data Source
AI summary
A memory system includes a memory device having a plurality of memory blocks, each including a plurality of pages, each page including a plurality of memory cells, wherein data provided from a host device is written on the plurality of pages and the plurality of memory cells coupled to a plurality of word lines; and a controller suitable for setting word line zones by grouping the plurality of word lines by a predetermined number, and performing a bad management for the memory blocks in each of the word line zones.