FAT檔案系統為一歷史悠久的檔案系統，但其廣泛之相容性及精簡之設計在現今的應用中仍然相當熱門，但受限FAT架構之限制，在檔案存取時間上並不足夠穩定，這使即時系統中使用標準FAT檔案系統可能面臨時限議題。
本論文基於能夠提供穩定存取時間之SD卡為儲存媒體，並根據即時系統應用之特性，以改善標準FAT檔案系統使其更適用於即時系統之應用，稱為RFAT，使即時系統操作檔案時亦能滿足其對時間限制之要求。本論文研究與設計之重點包含：(1)根據標準FAT檔案系統之規格設計具相容性之檔案系統與格式化工具；(2)針對小量資料之讀寫進行優化，使執行時間之波動降低；(3)設計儲存空間分配機制使RFAT能在面臨空間分配時仍維持穩定之執行時間；(4)設計資料救援工具與RFAT之運作進行搭配，應用程式所記錄之資料得以安全保存。為驗證本系統之設計可用性，本論文設計一系列測試，以確保本研究開發之RFAT系統能夠保有相容性且其穩定之存取時間可滿足即時系統應用所需。
本論文主要貢獻為設計與實作一平台獨立之RFAT函式庫，讓即時系統開發人員可根據需求將此函式庫作為系統開發之組件，以在即時系統應用中紀錄檔案。

The FAT file system is a long established file system, but its simplicity and broad compatibility with streamlined design still make it popular in modern applications. However, due to the limitations of the FAT architecture, file access times can be unstable and unpredictable, posing potential timing issues when using the standard FAT file system in real-time systems.

This thesis focuses on improving the interoperability of standard FAT file system so that it can be more suitable for real-time system applications using SD card as the storage medium. The file system, referred to as RFAT, is proposed to meet the requirement of predictable timing behavior of file operations when used in real-time systems. The key research and design aspects of this paper include: (1) Designing a compatible file system and formatting tool based on the standard FAT file system specifications; (2) Optimizing file operations of read and write for small amount of data to reduce fluctuations of execution time; (3) Developing a storage space allocation mechanism that allows RFAT to maintain stable execution times even when dealing with space allocation; (4) Creating data recovery tools to help maintain the intergrity of file system data recorded by applications is safely preserved. To verify the usability of the RFAT system design, a series of tests were conducted to ensure that the developed RFAT system maintains compatibility and that its stable access times can meet the requirements of real-time system applications.
The main contribution of this thesis is the design and implementation of a OS independent stand alone RFAT library, allowing real-time system developers to use this library as a component for system development that use file operations in real-time system applications.

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