Abstract
Due to the characteristics of the flash memory, the NAND flash memory-based storage device has become the favorite of the embedded system. However, the non-deterministic response time of reclaiming space, which is subject to out-of-place writes, always degrades the system performance. Moreover, the flash memory has the constraint of the limited erase counts. Hence, any excessive erase operations on certain block would lead the flash memory into the premature death. Wear-leveling policies are devoted to the victim selection to eliminate the wear deviation of each block. A periodic based approach is proposed in the previous study to remove the uncertainty of the write response time and get the flash memory erased evenly. However, the frequency to trigger the periodical mechanism has a strong impact on the performance of reclaiming space. The over-recycling incurs the extra cost when the system has no demand for the space. Oppositely, less frequency imposes insufficient space while serving the write requests. In this thesis, we propose a balanced reclaiming scheme named DBFTL which provides the predictability for the embedded system with deterministic response time while servicing each write request and guarantees enough free space by the appropriately triggered timing. The simulation results show that DBFTL can provide sufficient space to use at any time and has the better performance in read/write throughput.