TLC Flash Memory Write Recovery After Power Failure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Triple-Level Cell (TLC) flash memory is prone to data retention issues and power-off errors, leading to unfinished write operations and resource wastage due to its susceptibility to environmental factors and power failures, especially during unexpected power-off events.
Innovation Solution
A data writing method for TLC blocks in flash memory devices that checks for unfinished write operations after a power-off event, allowing successful data transfer from unfinished TLC blocks to new blocks if the last written page can be read, and moving error-prone data to temporary blocks for correction, thereby minimizing resource wastage and maintaining data integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If TLC blocks are used to increase storage capacity, then storage density is improved, but data retention and reliability deteriorate due to susceptibility to power-off errors
Solution Approach 1:
The patent applies preliminary action by checking the readability of the last written page before completing the write operation. This pre-check ensures that if the page is unreadable, the write operation is aborted before data is lost, preventing power-off errors from corrupting data in TLC blocks while maintaining high storage capacity
Solution Approach 2:
The patent implements feedback by continuously monitoring the write operation status and checking whether the last written page can be read. This feedback mechanism allows the system to detect potential data retention issues early and take corrective action, improving reliability without sacrificing the high storage density of TLC
2Reliability
If write operations are aborted when power-off events occur, then data integrity is improved, but resource wastage increases due to unfinished write operations
Solution Approach 1:
The patent uses preliminary action by checking the last written page's readability before aborting a write operation. This allows the system to determine whether the unfinished write operation can be safely completed or must be aborted, reducing resource wastage while maintaining data integrity
Solution Approach 2:
The patent applies discarding and recovering by checking whether the last written page is readable. If readable, the system recovers the write operation and completes it; if not readable, it discards the unfinished operation. This prevents unnecessary resource wastage while protecting data integrity
3Reliability
If the last written page is checked for readability, then data loss is reduced, but operation complexity increases due to additional checking steps
Solution Approach 1:
The patent performs a simple preliminary check of the last written page's readability. This single check provides sufficient information to determine whether to continue or abort the write operation, reducing data loss risk without significantly increasing operational complexity
Solution Approach 2:
The patent applies partial action by checking only the last written page rather than verifying the entire write operation. This partial check is sufficient to prevent data loss while minimizing the additional complexity introduced by the verification step
Data Source
AI summary
A data storage device including a flash memory and a controller is provided. The flash memory has a plurality of TLC blocks, each of which includes a plurality of pages. The controller checks whether any of the TLC blocks was undergoing a write operation and unfinished at the time that the power-off event occurred when the data storage device resumes operation after a power-off event. When a first TLC block was undergoing the write operation and unfinished at the time that the power-off event occurred, the controller further checks whether data stored in a page which was the last one being written in the first TLC block can be successfully read, and continues to write the remaining data into the first TLC block when the data of the page which was the last one being written in the first TLC block can be successfully read.