Threshold voltage sensing method and threshold voltage sensing system for solid-state disk flash memory chip

Abstract

The invention discloses a threshold voltage sensing method for a solid-state disk flash memory chip, and in particular relates to an optimal method mainly used for performing error correction on multiple layers of unit flash memory chips by using a low-density parity-check code. The system mainly comprises an LDPC encoding module, a flash memory chip storage module, a non-uniform threshold voltage sensing module, a log-likelihood ratio computation module and an LDPC decoding module, wherein the LDPC encoding module is mainly used for encoding original data to generate codons by using an LDPC generation matrix; the flash memory chip storage module is mainly used for storing data; the non-uniform threshold voltage sensing module is mainly used for performing non-uniform threshold voltage sensing on the flash memory chips; the log-likelihood ratio computation module is mainly used for obtaining a log-likelihood ratio value according to a threshold voltage value; the LDPC decoding module is mainly used for performing decoding error correction on the log-likelihood ratio value and a check matrix. The threshold voltage sensing method is mainly suitable for the field of solid-state disk error correction, and the reliability of data storage is improved.

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.

Images