Memory Controller Block Management for Flash Write Latency
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Solution Overview
Problem
The existing management methods for rewritable non-volatile memory modules face inefficiencies in access speed due to the need for data merging procedures when the number of available physical blocks in the free area is low, leading to prolonged write command execution times.
Innovation Solution
A block management method that groups physical blocks into data, free, and replacement areas, allowing for the replacement of bad blocks from the replacement area and the association of unused physical blocks in the free area with the replacement area, thereby optimizing the use of physical blocks and reducing the need for data merging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of available physical blocks in the free area is low, then data merging procedures are triggered, but write command execution time is prolonged
Solution Approach 1:
The patent applies preliminary action by proactively monitoring the number of available physical blocks in the free area and triggering data merging procedures before the free area becomes completely depleted. The memory management circuit executes data merging when the count falls below a threshold, preparing replacement blocks in advance to prevent write operations from being blocked, thus maintaining both reliability and reducing time loss.
2Reliability
If data merging procedure is executed frequently, then physical block availability is maintained, but access efficiency deteriorates
Solution Approach 1:
The patent implements feedback by continuously monitoring the number of available physical blocks in the free area and using this information to dynamically adjust when data merging procedures are executed. The memory management circuit maintains a count of free blocks and compares it against a threshold, triggering data merging only when necessary, thereby balancing block availability with access efficiency and avoiding unnecessary merging operations.
3Ease of operation
If physical blocks are strictly managed with fixed areas, then management simplicity is maintained, but block utilization efficiency decreases
Solution Approach 1:
The patent applies dynamics by making the boundaries between free area and replacement area flexible rather than fixed. The memory management circuit dynamically adjusts which physical blocks belong to the free area and which belong to the replacement area based on real-time monitoring of block availability. This dynamic management allows blocks to be reallocated between areas as needed, improving utilization efficiency while maintaining manageable complexity through systematic reclassification.
Data Source
AI summary
A block management method for managing physical blocks of a rewritable non-volatile memory, and a memory controller and a memory storage apparatus using the same are provided. The method includes grouping the physical blocks into at least a data area, a free area, and a replacement area, and grouping the physical blocks of the data area and the free area into a plurality of physical units. The method also includes when one of the physical blocks belonging to of the physical units of the data area becomes a bad physical block, getting a physical block from the replacement area and replacing the bad physical block with the gotten physical block. The method further includes associating a physical unit that contains no valid data in the free area with the replacement area. Thereby, the physical blocks can be effectively managed and the access efficiency can be improved.