Memory Management Grouping Physical Erasing Units for Bad Block Replacement
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Solution Overview
Problem
Memory storage devices experience reduced data access speed and erratic operation due to bad block management methods, which require additional processing when faulty blocks are detected across different operating units, leading to inefficient replacement and data movement.
Innovation Solution
A memory management method that groups physical erasing units into management units, where each unit has a fixed number of units belonging to different planes, allowing for in-plane replacement of bad blocks and recording replacement information in a management table to improve access stability and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bad block replacement is performed using blocks from different operating units, then faulty blocks can be replaced, but data access speed is significantly reduced
Solution Approach 1:
The patent divides the memory device into multiple operating units (planes, channels, or dies) and further segments them into block groups. By segmenting the replacement block selection to the same operating unit level, the patent maintains reliability for bad block replacement while minimizing cross-unit access that would slow down data operations.
Solution Approach 2:
The patent applies local quality by restricting bad block replacement to blocks within the same operating unit whenever possible. This creates a localized replacement strategy that maintains the specific performance characteristics of each operating unit, preventing the speed degradation that occurs with cross-unit access.
2Speed
If bad block replacement is not performed, then data access can continue by skipping faulty blocks, but additional processing is needed due to different block group sizes
Solution Approach 1:
The patent performs preliminary action by proactively replacing bad blocks with good blocks from the same operating unit before they cause access issues. This preventive approach maintains uniform block group sizes and eliminates the need for complex runtime processing to handle variable-sized groups.
Solution Approach 2:
The patent changes the parameter of block replacement location from 'any available block' to 'block within the same operating unit'. This parameter change simplifies the system by maintaining consistent block group structures, reducing the processing complexity associated with variable-sized groups.
3Reliability
If blocks are replaced across different operating units, then replacement can be performed, but operational stability deteriorates
Solution Approach 1:
The patent applies local quality by confining bad block replacement operations to the same operating unit. This maintains the structural integrity and operational characteristics of each unit, preventing the instability that arises from mixing blocks across different units with varying performance characteristics.
Solution Approach 2:
The patent promotes homogeneity by ensuring that replacement blocks come from the same operating unit as the faulty blocks. This maintains uniformity in block group composition and operating characteristics, thereby stabilizing the overall system operation.
Data Source
AI summary
A memory management method configured for a rewritable non-volatile memory module, a memory storage device, and a memory control circuit unit are provided. The rewritable non-volatile memory module includes a plurality of dies, wherein each of the dies includes a plurality of planes, each of the planes includes a plurality of physical erasing units, and a sum of a number of the planes included in the rewritable non-volatile memory module is a first number. The method includes: grouping the plurality of physical erasing units into a plurality of management units. Each of the plurality of physical erasing units included in each of the management units belongs to a different plane, and each of the management units has a second number of the physical erasing units, wherein the second number is less than the first number.