A method and system for sensing threshold voltage of a solid-state disk flash memory chip

Abstract

The invention discloses a threshold voltage perception optimization method of a flash memory chip inside a solid-state disk, which is mainly used for an optimization method when a multi-layer unit flash memory chip uses a low-density parity check code for error correction. The system structure is mainly composed of LDPC encoding module, flash memory chip storage module, non-uniform threshold voltage sensing module, logarithmic likelihood ratio calculation module and LDPC decoding module. The LDPC encoding module mainly uses LDPC to generate matrix encoding to generate codewords for the original data; the flash memory chip storage module mainly stores data; the non-uniform threshold voltage sensing module mainly senses the non-uniform threshold voltage of the flash memory chip; the log likelihood ratio calculation module is mainly composed of The threshold voltage value obtains the logarithmic likelihood ratio; the LDPC decoding module mainly performs decoding and error correction according to the loglikelihood ratio and the parity check matrix. The invention is applicable to the field of solid-state disk error correction and improves the reliability of stored data.

Description

technical field [0001] The invention belongs to the technical field of error correction of solid-state disk flash memory chips, and more particularly relates to a threshold voltage sensing method and system for solid-state disk flash memory chips. Background technique [0002] With the widespread application of various mobile devices in people's daily life, the flash memory chip (Not And, NAND Flash memory), which is one of the types of non-volatile memory, is playing an increasingly important role. Due to the physical structure of NAND Flash memory, errors are prone to occur. How to ensure the reliability of data has become one of the key technologies for the success of NAND Flash memory applications. Therefore, the reliability guarantee technology using error correction codes has become a key link in the application of NAND Flash memory, and has been widely used and researched. [0003] At present, the architecture of NAND Flash memory has developed from Single Layer Cell...

AI Technical Summary

Problems solved by technology

However, due to the interference of noise in the flash memory chip, the four threshold voltage windows will cross each other, so that there will be three cross threshold voltage windows, such as figure 2 As shown, the four threshold voltage windows appear to cross each other, so that when the threshold voltage is sensed in the cross threshold voltage window, the corresponding storage state cannot be correctly distinguished, and an error occurs.

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