Exploiting Virtual Channel Flash Management Issue for Cost-Efficient NAND Usage in Mobile Devices
The recent evolution of NAND flash memory technologies has lead wealthy memory and storage space not only for system usage, but also user’s preferences. Despite of the dramatic increase of flash capacity, the bandwidth of flash memory does not much evolved. Rather, the bandwidth of flash memory decreases due to the memory manufacture technologies. To overcome the bandwidth shrink for one flash memory interface, manufactures pack several flash memory die into one flash memory package, and the package interface is connected to host controller. However, this packaging could increase hardware and firmware overhead in terms of device complexity and cost. To mitigate cost issue of flash system development, we design and implement cost-efficient virtual channel based FTL. In the designed virtual channel FTL, the raw NAND chip is virtually divided into several regions, and each region is allocated to each virtual channel. Although the virtual channels cannot keep up with physical channels since all the channel cannot be utilized at the same time, it has better utilization of NAND flash chip with single channel FTL.
KeywordsNAND flash Cost-efficient Virtual-channel FTL Mobile device
This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology(No. 2010-0021094).
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