Non-Volatile Memory Data Duplication for Defect Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-volatile memory devices, the reduction in physical isolation between storage elements due to denser manufacturing leads to high read and write error rates, which existing error detection and correction techniques cannot effectively manage, especially when errors exceed a certain limit, and defect remapping reduces usable memory.
Innovation Solution
A controller identifies poorly performing memory locations and duplicates data to spare regions, allowing for dynamic management of defects without remapping, thereby improving memory performance and reducing error rates through real-time error correction and media management strategies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If error-correcting codes are used to correct errors, then some errors can be corrected, but the technique becomes ineffective when the number of errors exceeds a certain limit
Solution Approach 1:
The system performs preliminary defect identification and data duplication before errors occur. During write operations, data is proactively copied to spare regions based on predicted defect locations, so when read operations occur, the data is already protected against potential errors without needing complex real-time error correction
2Reliability
If defect remapping is used to direct logical memory address to different physical region, then defective physical region can be avoided, but total usable memory is reduced
Solution Approach 1:
Instead of remapping defective regions, the system creates copies of data in spare memory regions. This allows the original memory locations to remain accessible while providing backup copies, thus avoiding the loss of usable memory capacity that would result from remapping
Solution Approach 2:
The system identifies and isolates defective memory locations by copying data away from them, then recovers the defective regions for continued use by storing duplicate copies elsewhere. This allows defective regions to be recovered and remain part of the usable memory space
3Reliability
If data is duplicated to spare regions during write operations, then defect tolerance is improved, but write operation complexity increases
Solution Approach 1:
The system implements self-service by automatically identifying defective regions and performing data duplication without external intervention. The memory controller autonomously manages the duplication process, selecting target regions and executing copies without requiring complex external control logic
4Quantity of substance
If physical isolation between storage elements is reduced to achieve smaller products and more dense media, then storage density is improved, but read and write error rates increase
Solution Approach 1:
The system performs preliminary data duplication to spare regions before errors can occur during high-density storage operations. By proactively creating backups based on predicted defect locations, the system compensates for the increased error rates inherent in densely packed storage elements
Data Source
AI summary
Exemplary methods, apparatuses, and systems include a memory controller receiving a user payload to be written to a memory. The memory controller determines a plurality of locations within the memory within which the user payload will be written. After detecting the destination of the user payload, the memory controller detects, within a data structure, the presence of an identifier of a first location within a user data portion of the plurality of locations. The memory controller writes the user payload to the user data portion of the plurality of locations and, in response to detecting the presence of the identifier in the data structure, writes a copy of one or more bits in the user payload written to the first location to a spare data portion of the plurality of locations.