Write Once Recording Device Capacity Management
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Solution Overview
Problem
Conventional methods for pseudo overwriting in OTP memory devices lead to consumption of physical memory regions, causing inconsistencies in recorded capacity and incorrect reporting of remaining space, resulting in potential data recording errors.
Innovation Solution
Implementing a system where the access device accurately manages and reports the remaining recordable capacity by using a logical-physical empty capacity management part to track and notify the file system control of available space, ensuring accurate allocation and pseudo overwriting without consuming additional physical memory regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional pseudo overwriting methods are used in OTP memory, then data rewriting capability is achieved, but physical memory regions are consumed causing capacity inconsistency
Solution Approach 1:
The patent introduces a mapping table as an intermediary structure between logical addresses and physical addresses. This mapping table tracks which physical regions have been allocated and written to, enabling the system to manage pseudo overwriting without consuming additional physical memory regions. The mapping table acts as a mediator that resolves the contradiction by providing awareness of physical space usage without requiring extra physical storage.
Solution Approach 2:
The patent creates a virtual copy of the memory space through the mapping table, which mirrors the physical memory allocation state. This virtual copy allows the file system to understand actual used capacity without physically consuming additional space. The mapping table copies the allocation information, enabling accurate capacity tracking while maintaining the write-once physical constraint of OTP memory.
2Adaptability or versatility
If physical memory regions are consumed for pseudo overwriting, then overwriting function is enabled, but remaining capacity reporting becomes inaccurate
Solution Approach 1:
The mapping table provides continuous feedback about which physical memory regions have been allocated and written to. This feedback mechanism enables the system to accurately calculate remaining capacity by tracking actual physical usage. The mapping table updates allocation status information, providing real-time feedback that ensures accurate remaining capacity reporting throughout the pseudo overwriting process.
3Ease of operation
If access device relies solely on FAT for capacity management, then file system operation is simplified, but accurate remaining capacity cannot be determined in OTP memory
Solution Approach 1:
The mapping table serves multiple functions: it tracks physical address allocation, manages pseudo overwriting operations, and provides accurate capacity information. By making the mapping table multi-functional, the patent avoids adding complex separate mechanisms while achieving both simplified file system operation and accurate capacity management. The mapping table handles multiple tasks that would otherwise require separate systems.
Data Source
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AI summary
An access device 1 internally includes a logical-physical empty capacity management part 16 for obtaining information of a remaining capacity on a write once memory from a write once recording device 2A. In addition, the write once recording device 2A internally includes a physical empty capacity management part 27 for managing a remaining capacity on the write once memory and notifying the access device of the capacity. Prior to recording of file data, the access device 1 can know an accurate remaining capacity of the write once recording device by: obtaining a remaining capacity of the write once memory from the write once recording device 2A; and comparing the capacity with a remaining capacity on an FAT to decide an actually-recordable remaining capacity for file data.