Memory System Open Block Recovery via Preliminary Data Copying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Memory systems face challenges in recovering from sudden power-offs, leading to data damage and premature exhaustion of free blocks during repeated recovery operations, which affects data reliability and device lifespan.
Innovation Solution
A memory system and operating method that involve copying data from an open block to a selected block, maintaining open block identification information, and storing log data to facilitate recovery, allowing for efficient reuse of blocks without updating identification information, thereby preventing free block exhaustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data of an open block is copied to a selected block during sudden power-off recovery, then data reliability is improved, but free blocks are exhausted prematurely
Solution Approach 1:
The system performs preliminary copying of open block data to a selected block before power-off occurs, and maintains open block identification information so that the same block can be reused in subsequent recovery operations. This preliminary preparation allows the system to recover data without consuming additional free blocks during repeated power-off events.
Solution Approach 2:
Instead of discarding the selected block after copying data during recovery, the system recovers and reuses the selected block by maintaining its identification information as an open block. This allows the block to be reused in future recovery operations, preventing free block exhaustion while maintaining data reliability.
2Manufacturing precision
If open block identification information is updated after recovery, then block management accuracy is improved, but device lifespan is reduced
Solution Approach 1:
Instead of updating the open block identification information after recovery (the conventional approach), the system inverts this logic by maintaining the same identification information. This inversion allows the selected block to be reused as an open block in subsequent recovery operations, extending device lifespan while maintaining sufficient block management accuracy through log data validation.
Solution Approach 2:
The system copies the open block identification information from the previous power cycle and maintains it, rather than creating new identification information. This copying approach allows the system to reuse the same block for recovery operations, reducing wear on the device while maintaining data integrity through the copying and verification process.
3Productivity
If log data is stored in a meta block to track recovery operations, then recovery efficiency is improved, but memory complexity increases
Solution Approach 1:
The system introduces a meta block as an intermediary structure to store log data that tracks the state of open blocks and recovery operations. This intermediary allows the system to efficiently manage recovery operations by providing a centralized record of block states, while the simplicity of the log data structure (storing only essential state information) keeps the overall memory complexity manageable.
Data Source
AI summary
Disclosed is an operating method of a memory system that includes a plurality of memory blocks, the operating method including a first step of copying, in order to recover sudden power-off of the memory system, data of an open block to a selected block among the plurality of memory blocks while maintaining map data associated with the open block and open block identification information; a second step of erasing the open block; and a third step of copying the data, which is copied to the selected block, to the erased open block.