{"title":"LLD:针对 3-D TLC NAND 闪存的 LDPC 硬解码轻量级延迟降低方案","authors":"Debao Wei;Yongchao Wang;Hua Feng;Huqi Xiang;Liyan Qiao","doi":"10.1109/TCSI.2024.3438789","DOIUrl":null,"url":null,"abstract":"The low-density parity-check code (LDPC) has been widely used to significantly enhance the reliability of 3-D NAND flash memory. However, in cases where the raw bit error rate (RBER) of the data is high, it not only demands more sense levels but also requires a large number of iterations, leading to a notable read latency issue. To mitigate this challenge, this paper introduces an innovative lightweight latency decrease (LLD) scheme. Initially, by examining the correlation between the number of iterations and the hard decision level (HDL), a functional model that encapsulates the relationship between iteration and offset is established. Building upon this model, the all-wordlines latency decrease (AWLD) scheme is proposed. In an effort to further decrease latency, an in-depth analysis of the similarities among different wordlines within a flash memory block is conducted, leading to the development of an optimized one-wordline lightweight latency decrease (OWLLD) scheme. For scenarios involving random reading of small data volumes, the interplay between function models of various overlapping regions is delved into, which ultimately results in the proposal of a further optimized one-page lightweight latency decrease (OPLLD) scheme. Experimental findings reveal that the OPLLD scheme can enhance the iterative performance of LDPC by up to 94.63% and reduce latency by up to 66.89% compared to traditional algorithms, while incurring minimal storage and computational overhead. This clearly indicates that the proposed scheme substantially enhances the read latency performance of LDPC in flash memory.","PeriodicalId":13039,"journal":{"name":"IEEE Transactions on Circuits and Systems I: Regular Papers","volume":null,"pages":null},"PeriodicalIF":5.2000,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"LLD: Lightweight Latency Decrease Scheme of LDPC Hard Decision Decoding for 3-D TLC NAND Flash Memory\",\"authors\":\"Debao Wei;Yongchao Wang;Hua Feng;Huqi Xiang;Liyan Qiao\",\"doi\":\"10.1109/TCSI.2024.3438789\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The low-density parity-check code (LDPC) has been widely used to significantly enhance the reliability of 3-D NAND flash memory. However, in cases where the raw bit error rate (RBER) of the data is high, it not only demands more sense levels but also requires a large number of iterations, leading to a notable read latency issue. To mitigate this challenge, this paper introduces an innovative lightweight latency decrease (LLD) scheme. Initially, by examining the correlation between the number of iterations and the hard decision level (HDL), a functional model that encapsulates the relationship between iteration and offset is established. Building upon this model, the all-wordlines latency decrease (AWLD) scheme is proposed. In an effort to further decrease latency, an in-depth analysis of the similarities among different wordlines within a flash memory block is conducted, leading to the development of an optimized one-wordline lightweight latency decrease (OWLLD) scheme. For scenarios involving random reading of small data volumes, the interplay between function models of various overlapping regions is delved into, which ultimately results in the proposal of a further optimized one-page lightweight latency decrease (OPLLD) scheme. Experimental findings reveal that the OPLLD scheme can enhance the iterative performance of LDPC by up to 94.63% and reduce latency by up to 66.89% compared to traditional algorithms, while incurring minimal storage and computational overhead. This clearly indicates that the proposed scheme substantially enhances the read latency performance of LDPC in flash memory.\",\"PeriodicalId\":13039,\"journal\":{\"name\":\"IEEE Transactions on Circuits and Systems I: Regular Papers\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.2000,\"publicationDate\":\"2024-09-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"IEEE Transactions on Circuits and Systems I: Regular Papers\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://ieeexplore.ieee.org/document/10681227/\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, ELECTRICAL & ELECTRONIC\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"IEEE Transactions on Circuits and Systems I: Regular Papers","FirstCategoryId":"5","ListUrlMain":"https://ieeexplore.ieee.org/document/10681227/","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
LLD: Lightweight Latency Decrease Scheme of LDPC Hard Decision Decoding for 3-D TLC NAND Flash Memory
The low-density parity-check code (LDPC) has been widely used to significantly enhance the reliability of 3-D NAND flash memory. However, in cases where the raw bit error rate (RBER) of the data is high, it not only demands more sense levels but also requires a large number of iterations, leading to a notable read latency issue. To mitigate this challenge, this paper introduces an innovative lightweight latency decrease (LLD) scheme. Initially, by examining the correlation between the number of iterations and the hard decision level (HDL), a functional model that encapsulates the relationship between iteration and offset is established. Building upon this model, the all-wordlines latency decrease (AWLD) scheme is proposed. In an effort to further decrease latency, an in-depth analysis of the similarities among different wordlines within a flash memory block is conducted, leading to the development of an optimized one-wordline lightweight latency decrease (OWLLD) scheme. For scenarios involving random reading of small data volumes, the interplay between function models of various overlapping regions is delved into, which ultimately results in the proposal of a further optimized one-page lightweight latency decrease (OPLLD) scheme. Experimental findings reveal that the OPLLD scheme can enhance the iterative performance of LDPC by up to 94.63% and reduce latency by up to 66.89% compared to traditional algorithms, while incurring minimal storage and computational overhead. This clearly indicates that the proposed scheme substantially enhances the read latency performance of LDPC in flash memory.
期刊介绍:
TCAS I publishes regular papers in the field specified by the theory, analysis, design, and practical implementations of circuits, and the application of circuit techniques to systems and to signal processing. Included is the whole spectrum from basic scientific theory to industrial applications. The field of interest covered includes: - Circuits: Analog, Digital and Mixed Signal Circuits and Systems - Nonlinear Circuits and Systems, Integrated Sensors, MEMS and Systems on Chip, Nanoscale Circuits and Systems, Optoelectronic - Circuits and Systems, Power Electronics and Systems - Software for Analog-and-Logic Circuits and Systems - Control aspects of Circuits and Systems.