Spare Area Management for Storage Media Defect Handling
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Solution Overview
Problem
Conventional information storage media lack effective management of spare areas, leading to inefficiencies in defect management due to random arrangement of replaced and usable spare blocks, which increases the time required for defect management.
Innovation Solution
The implementation of a next available position pointer in the defect management area to indicate a usable spare block without replacement blocks in the forward part of the usage order, ensuring that only non-replacement spare blocks are used for defect substitution, thereby reducing the time needed for defect management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spare blocks are sequentially used in the spare area, then defect management can be performed, but replaced spare blocks and usable spare blocks may be arranged at random, increasing the time required for defect management
Solution Approach 1:
The patent applies preliminary action by pre-organizing spare blocks into distinct regions (usable spare block region and replaced spare block region) before defect management operations. The defect management area stores management information that identifies which spare blocks are usable and their positions in advance, so when a defect occurs, the system can immediately access pre-identified usable spare blocks without searching through randomly arranged blocks, thereby reducing defect management time while maintaining reliability
2Productivity
If replacement entries are removed from the defect list, then replaced spare blocks can be reused, but the arrangement of usable and replaced spare blocks becomes random, complicating spare area management
Solution Approach 1:
The patent applies segmentation by dividing the spare area into distinct regions: a usable spare block region for storing available spare blocks and a replaced spare block region for storing previously used spare blocks. The defect management area stores management information that identifies and separates these regions. This segmentation allows the system to efficiently track and manage replaced spare blocks that can be reused while maintaining clear organization, thereby improving spare block utilization efficiency without excessively increasing management complexity
Solution Approach 2:
The patent uses the defect management area as an intermediary that stores management information about spare blocks. This intermediary structure maintains records of which spare blocks are usable, their positions, and their status (whether they have been replaced before). By using this intermediary management layer, the system can track and manage the complex arrangements of usable and replaced spare blocks efficiently, enabling high productivity without proportional increases in management complexity
Data Source
Figure 1(A)~1(B)
Figure 2
Figure 3
AI summary
An information storage medium includes: a user data area for recording user data; a spare area including spare blocks each for replacing a defective block occurring in the user data area; and a defect management area in which information about the defective block occurring in the user data area is recorded, wherein the spare blocks of the spare area include usable spare blocks with replacement blocks existing in forward parts of the usable spare blocks in a usage order, and usable spare blocks without replacement blocks existing in forward parts of the usable spare blocks in the usage order, wherein a next available position pointer of the spare area is recorded in the defect management area, and the next available position pointer of the spare area indicates a first usable spare block from among the usable spare blocks without the replacement blocks existing in the forward parts of the usable spare blocks in the usage order.