Lim Seung-Ho, Park Ki-Woong
Division of Computer and Electronic Systems Engineering, Hankuk University of Foreign Studies, Yongin 17035, Korea.
Department of Computer and Information Security, Sejong University, Seoul 05006, Korea.
Sensors (Basel). 2020 May 22;20(10):2952. doi: 10.3390/s20102952.
NAND flash memory-based storage devices are vulnerable to errors induced by NAND flash memory cells. Error-correction codes (ECCs) are integrated into the flash memory controller to correct errors in flash memory. However, since ECCs show inherent limits in checking the excessive increase in errors, a complementary method should be considered for the reliability of flash storage devices. In this paper, we propose a scheme based on lossless data compression that enhances the error recovery ability of flash storage devices, which applies to improve recovery capability both of inside and outside the page. Within a page, ECC encoding is realized on compressed data by the adaptive ECC module, which results in a reduced code rate. From the perspective of outside the page, the compressed data are not placed at the beginning of the page, but rather is placed at a specific location within the page, which makes it possible to skip certain pages during the recovery phase. As a result, the proposed scheme improves the uncorrectable bit error rate (UBER) of the legacy system.
基于NAND闪存的存储设备容易受到NAND闪存单元引发的错误影响。纠错码（ECC）被集成到闪存控制器中以纠正闪存中的错误。然而，由于ECC在检查错误的过度增加方面存在固有局限性，因此应考虑采用一种补充方法来提高闪存存储设备的可靠性。在本文中，我们提出了一种基于无损数据压缩的方案，该方案增强了闪存存储设备的错误恢复能力，适用于提高页面内外的恢复能力。在页面内，自适应ECC模块对压缩数据进行ECC编码，这导致编码率降低。从页面外的角度来看，压缩数据不是放置在页面开头，而是放置在页面内的特定位置，这使得在恢复阶段可以跳过某些页面。结果，所提出的方案提高了传统系统的不可纠正误码率（UBER）。
