3D-FlashMap: a physical-location-aware block mapping strategy for 3D NAND flash memory

Abstract

Three-dimensional (3D) flash memory is emerging to fulfil the ever-increasing demands of storage capacity. In 3D NAND flash memory, multiple layers are stacked to increase bit density and reduce bit cost of flash memory. However, the physical architecture of 3D flash memory leads to a higher probability of disturbance to adjacent physical pages and greatly increases bit error rates. This paper presents 3D-FlashMap, a novel physical-location-aware block mapping strategy for three-dimensional NAND flash memory. 3D-FlashMap permutes the physical mapping of blocks and maximizes the distance between consecutively logical blocks, which can significantly reduce the disturbance to adjacent physical pages and effectively enhance the reliability. We apply 3D-FlashMap to a representative flash storage system. Experimental results show that the proposed scheme can reduce uncorrectable page errors by 85% with less than 2% space overhead in comparison with the baseline scheme.