Memory Controller Read Retry via Mask Map Update
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current memory systems face inefficiencies in read retry operations due to the need for generating new read descriptors, which increases operation time and overhead.
Innovation Solution
The proposed memory system reduces read retry operation time and overhead by updating existing read descriptors without generating new ones, using a method that involves performing ECC operations and updating mask map bits based on error report bits to optimize read operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If new read descriptors are generated for read retry operations, then read retry can be performed, but memory space and operation time increase
Solution Approach 1:
The patent uses a mask map as a simplified copy or representation of the error report map, where only the necessary error indication bits are retained and updated. This allows the read retry operation to function with a reduced descriptor structure, avoiding the need to generate complete new read descriptors while maintaining the essential error tracking functionality.
2Reliability
If new read descriptors are generated for read retry operations, then read retry can be performed, but memory space consumption increases
Solution Approach 1:
The patent extracts only the essential error report bits from the full read descriptor and places them in a separate mask map. This extraction allows the main read descriptor to remain unchanged while a minimal mask map structure tracks error states for retry operations, significantly reducing the memory space required for read retry functionality.
Solution Approach 2:
The mask map serves as a compact copy of the error report information, containing only the necessary mask map bits that indicate which pages require retry. This copied structure uses minimal memory compared to generating complete new read descriptors, while preserving the essential error tracking capability.
3Device complexity
If read descriptors are updated by reading the initial read descriptor, then overhead is reduced, but additional read operations are required
Solution Approach 1:
The patent performs a preliminary read of the initial read descriptor to obtain the error report map before generating the mask map. This preliminary action allows subsequent mask map updates to proceed efficiently without repeatedly reading the full descriptor, reducing overall overhead while managing the initial read cost.
Data Source
AI summary
A memory system includes: a memory device including a plurality of pages; and a controller suitable for generating a read descriptor in response to an entered command, reading and outputting read data stored in at least one page in response to the read descriptor, determining whether each per-page data of the read data includes an error, storing indicators for showing whether each per-page data includes the error, re-reading some of the read data on per-page basis, based on the indicators, without generating another read descriptor, and updating the indicators based on an error check result after the re-reading.