Dual-target state elimination coding and decoding method adaptive to 3D TLC type NAND flash memory data storage

Abstract

The invention provides a dual-target state elimination encoding and decoding method adaptive to 3D TLC type NAND flash memory data storage, which comprises the following steps: preprocessing cell element data through an encoder, storing 3-bit information in each cell element, enabling the cell elements to have eight states N, pairing the eight states in pairs, equally dividing the eight states into four groups, and recording the four groups as Gi; setting one group of GX as double states of target elimination, dividing an original data stream according to the length of a word line, taking four cell elements as a code segment of coding, recording the number num (N) of eight states in the code segment of the four cell elements, and obtaining a remapping coding method according to the state combination in the code segment; storing the remapped and coded information into different blocks of a flash memory; and enabling the decoder to remap the four-cell code segment into original data according to the flag bit; the method disclosed by the invention can be used as a universal method, and the reliability of the 3D TLC type NAND flash memory is improved.

Description

technical field [0001] The invention belongs to the field of non-volatile storage, and in particular relates to a dual-target state elimination encoding and decoding method adapted to 3D TLC type NAND flash memory data storage. Background technique [0002] At present, 3D TLC (Trinary-Level Cell, which stores 3 bits of information in each cell) NAND flash memory is widely used in non-volatile storage scenarios such as solid-state disks. A large number of studies have shown that the data storage reliability of 3D TLC NAND flash memory and The programmed threshold voltage distribution pattern is closely related. [0003] In recent years, 3D TLC-type NAND flash memory has been widely used as a solution for non-volatile storage media due to its advantages such as low access delay, low power consumption, and high shock resistance. In addition to the higher integration level, it also caused a significant reduction in the reliability of NAND flash memory. Take the wear resistance ...

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Problems solved by technology

[0003] In recent years, 3D TLC-type NAND flash memory has been widely used as a solution for non-volatile storage media due to its advantages such as low access delay, low power consumption, and high shock resistance. In addition to the higher integration level, it also caused a significant reduction in the reliability of NAND flash memory. Take the wear resistance of write / erase cycles as an example. Traditional SLC (Single-Level Cell, each cell stores 1 bit information) type NAND flash memory can achieve more than 100,000 times of wear endurance, while 3D TLC type NAND flash memory will cause serious distortion of stored data after thousands of times of wear and tear. Therefore, how to introduce appropriate reliability management The method prolongs the service life of the device, which is an important research topic for the application of non-volatile storage systems based on 3D TLC-type NAND flash memory

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