MLC Flash Memory Data Recovery via Preliminary Copying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-level cell (MLC) flash memory devices suffer from data loss during power off events during program cycles, particularly affecting paired pages, leading to significant data integrity issues.
Innovation Solution
A program method that copies data from a page to non-volatile memory before programming a paired page and a data recovery method that moves data to a clean block and programs backup data in case of program failure, ensuring data recovery even in the event of power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data is copied to non-volatile memory before programming paired pages, then data reliability is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by copying data from pages to a non-volatile memory region before programming the paired pages. This preparatory step ensures that if power is lost during the programming process, the original data can be recovered from the non-volatile memory, thus preventing data loss while maintaining a relatively simple device architecture.
2Reliability
If data recovery procedures are implemented, then data loss prevention is improved, but processing time increases
Solution Approach 1:
The recovery procedure is prepared in advance by maintaining a non-volatile memory region that continuously holds copies of page data. When power is restored after a failure, the system can quickly detect which paired pages failed to program and recover their data from the pre-stored non-volatile memory, avoiding time-consuming data reconstruction processes.
Solution Approach 2:
The system performs self-service by automatically detecting program failures and recovering data without requiring external intervention. The controller monitors programming operations, identifies failed paired pages, and autonomously recovers data from the non-volatile memory region, reducing the time users need to wait for manual recovery procedures.
3Reliability
If non-volatile memory is used for data copying, then data integrity is improved, but memory capacity is reduced
Solution Approach 1:
The patent extracts a specific portion of the flash memory to function as a non-volatile memory region dedicated to storing backup copies of page data. By separating this protective function from the main storage area, the system ensures data integrity for the extracted region while preserving the overall memory capacity for user data.
Solution Approach 2:
The patent applies local quality by designating specific regions within the flash memory with different functions: the non-volatile memory region maintains high data integrity for backup purposes, while the remaining memory capacity is optimized for general storage. This localized differentiation allows each region to excel at its specific function without compromising the other.
Data Source
AI summary
A program method for a multi-level cell (MLC) flash memory is provided. The memory array includes a plurality of pages and a plurality of paired pages, which correspond to the respective pages. The program method includes the following steps. Firstly, a program address command is obtained. Next, whether the program address command corresponding to any one of the paired pages is determined. When the program address command corresponds to a first paired page, which corresponds to a first page among the pages, among the paired pages, data stored in the first page to a non-volatile memory are copied. After that, the first paired page is programmed.