快閃記憶體(NAND Flash Memory)有著體積小、功耗低、抗震、存取速度快等優點，並隨著移動設備的興起，逐漸成為用戶市場的主流儲存媒介。不過快閃記憶體也有先天的限制，例如: 無法覆寫、不對稱的寫入與抹除單位、有抹除次數的限制…等，因此衍生出一套快閃記憶體轉換層來有效率地管理NAND Flash，並利用RAM維護一個邏輯位址到實體位址的映射表，如此一來可以快速地修改映射資訊。此外，為了降低寫入操作，快閃記憶體轉換層與主機端之間通常會使用RAM建立一套寫入緩衝機制以延長快閃記憶體的使用壽命。基於硬體的共同性，本篇論文提出一個動態配置記憶體的方法，分配映射表與緩衝的記憶體大小，以降低NAND Flash的寫入量。最後實驗顯示，我們的動態調整記憶體機制在大多數Workload下都逼近取樣之最佳靜態記憶體配置的寫入量，與最多寫入量之靜態記憶體配置相比，平均降低了近27%的寫入。

NAND Flash Memory has some advantages of small size, low power consumption, shock resistance, and fast access speed. With the rise of mobile devices, it gradually becomes the main storage medium in the user market. However, flash memory also has its limitations, such as inability to overwrite, asymmetric writing and erasing units, restrictions on the number of erasing ...etc. Therefore, flash translation layer(FTL) is derived to manage flash memory effectively. It uses RAM to maintain a mapping table for storing information of logical address to physical address. Moreover, in order to reduce write operation, a write buffer will be established between host layer and FTL layer to prolong the lifetime of flash memory. Based on using the same hardware resource(RAM), this paper proposes a method of dynamic memory allocation, which allocates the memory size of the mapping table and write buffer to reduce write operation. Finally, experiments show that under most workloads our dynamic memory allocation method approaches lowest write number from the static memory allocation we sampled. Compared with the static memory allocation with the highest write number, our method reduces 27% number of writes on average.

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