由於NAND Flash Memory 具有其限制特性，快閃記憶體轉換層Flash Translation Layer (FTL) 被設計出來為了管理Flash Memory 的這些限制特性，FTL 方法是建構在位址轉換(address translation)，垃圾回收(garbage collection)，跟耗損平均(wear-leveling)三大機制上，而當我們使用Flash Memory 儲存數據時，為了去回收不必要之空間及釋放可用空間必需去考慮垃圾回收方法，為了提高Flash Memory 的使用壽命，耗損平均機制被提出用以管理每一個block。針對上述兩大機制，現今有許多的FTL 垃圾回收方法被提出、改良及設計，為
了能夠方便設計者去分析及理解各種FTL 垃圾回收方法，本文提出了基於模組化設計之垃圾回收方法，本文是根據獨立性、組合性以及可分析性，去設計模組化之垃圾回收方法，其模組化設計方法包含耗損平均機制，透過這三種特性設計者可以輕鬆地分析，設計和重新設計的各種FTL 垃圾回收方法，以及能夠更清楚地了解各種FTL 垃圾回收方法。

NAND flash memory has become a popular storage system alternative, because of its advantages of non-volatility, shock-resistance, and low-power consumption. However, NAND flash memory is a write-once system and any existing data on flash memory cannot be updated. The update data must be written to free space and the old versions of data are invalidated and considered dead. One main function of flash translation layers is called garbage collection, which consists of a series of reads, writes, and erases operations to recycle the invalid data. During the execution of garbage collection, it is important to properly control write and erase operations
of all blocks by using a wear-leveling algorithm to improve the endurance of flash memory. In the thesis, we propose a component-based garbage collection design for flash memory. The component-based design is based on three features: specificity, composability and analyzability. With the component-based design, it can facilitate developers to realize and redesign the garbage collection and wear-leveling effect of flash memory.

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