Flash storage data access method

Abstract

The invention provides a data access method based on a multi-level (MLC) flash memory. Before the data is stored, the received original data is transcoded to obtain the transcoded data, and then the data is stored; before the data is read , perform reverse coding processing on the stored transcoding data to obtain restored data, and then read the data after performing error correction processing on the data. Through the transcoding processing method provided by the present invention, the number of bits in which errors occur in data information can be reduced, and the probability of errors in high-bit data information can be reduced. When performing error correction processing on the above-mentioned restored data, a simple error correction algorithm with a low bit error correction capability can be used to achieve a higher bit data error correction capability, thereby achieving what can only be achieved by using a complex error correction algorithm in the prior art High bit data error correction effect.

Description

technical field [0001] The invention relates to flash memory data access technology, in particular to a data access method based on multi-level (MLC) flash memory. Background technique [0002] With the development of flash memory (Flash Memory) technology, a new type of MLC flash memory has emerged, which may replace the traditional single-level (SLC) flash memory and become the mainstream flash memory medium. [0003] MLC is a unit that stores 2-bit data in a floating gate structure unit, and the data information stored in an MLC unit may be 00, 01, 10 or 11. In an MLC unit, the storage area is arranged from high to low according to the level, which can be divided into 00, 01, 10 and 11 levels, corresponding to the storage data information 00, 01, 10 or 11 respectively. For example, when data 01 needs to be stored, the level is adjusted to level 01, indicating that data information 01 is stored in this MLC unit; when data needs to be read, according to the level level at ...

AI Technical Summary

Problems solved by technology

For MLC flash memory, it is usually necessary to adopt a more complex data error correction processing method to meet the needs of its 4-bit data error correction capability, for example, the standard ECC algorithm with 4-bit data error correction capability and Reed-Solomon (RS ) algorithms are mixed for data error correction processing, so that stronger data error correction capabilities can be achieved, and the 4-bit data error correction capabilities required by MLC flash memory can be achieved, but at the same time it has to occupy a longer codeword

[0025] It can be seen that the existing data access method adopted by the MLC flash memory makes the probability of high-bit information errors in the data higher, so a complex data error correction algorithm with at least 4-bit data error correction capability must be used to achieve MLC 4-bit data error correction capability necessary for flash memory use

Images