Memory Controller Block Allocation for Defect Balancing
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Solution Overview
Problem
Existing memory systems face challenges in maintaining consistent write performance due to variations in the number of defective physical blocks within composition blocks, leading to increased write error rates and performance deterioration.
Innovation Solution
The memory system employs a controller to allocate physical blocks into first block sets, groups these sets based on the number of defective blocks, and selectively combines them to form second block sets with a balanced number of defective blocks, thereby stabilizing write performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical blocks are allocated to composition blocks without grouping by defective block count, then allocation simplicity is maintained, but write error rate increases and write performance deteriorates
Solution Approach 1:
The patent segments physical blocks into first block sets based on the number of defective blocks they contain. This segmentation allows the system to treat different blocks differently according to their defect characteristics, enabling balanced composition block formation that reduces write errors while maintaining manageable allocation complexity through systematic grouping.
Solution Approach 2:
The patent applies local quality by forming second block sets with balanced defective block counts from the segmented first block sets. This ensures that each composition block has a representative mix of defective and non-defective physical blocks, improving write reliability locally across the memory system without requiring complex global analysis.
2Productivity
If composition blocks are formed with unbalanced defective block distribution, then formation simplicity is maintained, but write processing performance deteriorates
Solution Approach 1:
The patent segments physical blocks into first block sets categorized by their defective block counts, then combines these segments to form second block sets with balanced defect distributions. This segmented approach achieves balanced composition blocks that improve write processing performance while keeping the formation process systematic and manageable.
Solution Approach 2:
The patent dynamically forms second block sets by selecting from the segmented first block sets to achieve balanced defective block counts. This dynamic formation process allows the system to adapt to varying defect patterns in the memory system, optimizing write performance while maintaining a structured formation methodology.
Data Source
AI summary
According to one embodiment, a memory system includes a non-volatile memory including a plurality of physical blocks and a controller. The controller is configured to allocate the plurality of physical blocks to a plurality of first block sets each including physical blocks among the plurality of physical blocks, generate a plurality of groups obtained by grouping the plurality of first block sets by the number of defective physical blocks included in each of the plurality of first block sets, and select a plurality of the first block sets from at least two groups of the plurality of groups to generate a second block set from the plurality of selected first block sets.