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영어

Recently, the density of Flash memory has dramatically increased by moving to smaller geometries and storing more bits per cell with enhanced memory technologies. However, with the density increasing rapidly, the error rate of Flash memory is also increasing rapidly. To improve the reliability issue of upcoming flash memory, usually, redundancy techniques were adopted in both of architecture and operations for flash memory based systems. For outside the flash memory page, several reliability schemes were proposed which employ Redundant Array of Inexpensive Disks (RAID). In this paper, we propose in-block level redundancy scheme for providing reliability of flash memory while minimizing maintaining overhead of the redundancy. In the proposed scheme, the redundancy is generated in a flash memory block level. During the programming stage of a flash block, the redundancy is kept in Dram memory. If a block is exhausted with last-1 page to record incoming data, the in-keeping redundancy is flushed to last page of the block. By doing this, block level redundancy is maintained with minimal overhead.