Nand chips , which do not lose data when power is turned off , are also used for flash drives that consumers use to store photos , documents , music and other multimedia data as well as the new solid - state drives for pcs Nand芯片在断电情况下不会造成数据丢失，同时可用于存储图片、文档、 、音乐和其他多媒体数据的存储卡，以及用于个人电脑的新的电晶体硬盘。
Have transplanted and tested the r / w yaffs file system to nand flash memory , build cramfs + yaffs multi file system on the basis of this . have solved problems about the dynamic access of the data and systematic issue of stability in the system 针对nand型闪存移植并测试了可读写的yaffs文件系统,基于此构建了cramfs + yaffs的多文件系统,解决了家庭网关中动态数据存取和系统的安全稳定性问题。
Because the reliability of nand flash chip is relatively low , the error detection and correction algorithm is discussed , and an algorithm fit for embedded system is introduced . also in the file system , an wear leveling function is provided 由于闪存芯片的可靠性相对较差，文中结合差错校验机制( ecc )与差错纠正机制( edc )的原理实现了适合嵌入式系统的ecc与edc的算法，并为该文件系统实现了平衡擦写算法。
Firstly , i introduce the hardware and software platform of embedded system , and explain the basic hardware and software development , it ’ s a cooperate process . then i analyse the cross development method for embedded system , mentioned the “ host ” and “ target ” in the development of an embedded system . take e - book project as an example , follows the process to introduce a real embedded system project , including the mcu , periphery hardware and the integrated development environment which can provide the whole platform for an integrated development on the pc - - wb33 . then i present 3 of the hardware of e - book . for lcd , i introduce the common feature of lcd , the ssct lcd as well as the design , actualize of its driver . for the rs232 serial port , the principle of the serial port and the main driver of it are introduced . for flash memory , i introuce the principle of nor flash and nand flash , and how their drivers implemented . in the end , the conclusion of this paper is generated , there is also a prospect for further research 以一个实际的嵌入式开发项目? ?电子阅读器为例,按照项目开发流程,介绍了包括项目所使用的微控制器mcu及片内周边电路;项目所使用的基于mcu的集成开发环境? ?能在pc机上提供完整集成开发的平台wb33 ,使用它可以很方便的在pc机上模拟目标机的环境。详细介绍了电子阅读器的三个底层硬件:对项目中采用的ssctlcd的特性以及其驱动的设计和实现的过程进行了详细介绍;对rs232串口驱动,介绍了接收端即电子阅读器端实现串口驱动接口的主要函数;对flash闪存驱动,分别介绍了norflash和nandflash的原理以及它们的驱动实现。最后,对全文给以总结,并对以后进一步的研究做出了展望
For r nexample , if you have a bank account class with a field that represents r nthe current balance and a field that contains a list of all deposits r nand withdrawals since the opening of the account , then you would have a r nclass invariant that states that the value of the balance field is r nequal to the total of all the deposit values so far minus the total of r nall the withdrawal values so far 例如，你有一个银行帐户类，它包含一个表示当前余额的字段和一个包含帐户自开通以来所有储蓄和支取清单的字段，那么你也应该有一个类不变式表明余额字段的值与累计储蓄和累计支取之差相一致。
For most embedded linux is based on linux 2 . 4 at now , the research of this paper is to build an embedded linux based on linux 2 . 6 kernel and port it to armer9 - ii platform finally . and it ’ s aimed at making the nand flash the main storage of the embedded linux in order to take full advantage of its mass storage and low cost 基于嵌入式linux发展趋势及其应用特点,针对目前嵌入式linux系统多是基于linux2 . 4内核的现状,本次研究的目的在于在armer9 - ii平台上研究并实现基于linux2 . 6内核的嵌入式linux系统,同时充分利用nandflash闪存高容量低成本的特点,使用nandflash闪存作为嵌入式linux系统的主要存储设备。
The research area covered by the thesis includes embedded system design , hardware infrastructure of embedded gis system , architecture of nand flash , error detect code / error check code and there algorithm , journal file system , gis file index , wear leveling for nand flash , file system page cache and write delay , dynamic compression in file system etc . first , the thesis first analysis the embedded gis status in quo , technology background , difficulty it facing 本文研究领域涉及嵌入式系统开发、嵌入式gis系统软硬件框架、 nand芯片体系结构、差错检测差错校验( edc ecc )算法、日志文件系统、文件索引、芯片擦写平衡、文件系统页面cache与延迟写技术、文件系统实时压缩等技术。
On the other nand , based on users " requirement and higher mining efficiency , this paper presents a definition of simple consequent association rules whose consequent includes just one item . the size of simple consequent association rules set is smaller than that of classical association rules mining algorithm . moreover , all of the composed association rules can be produced 另外基于用户需求和提高系统挖掘效率的需求，本文又提出了单一后件关联规则的定义，单一后件关联规则集与经典关联规则挖掘中规则集相比要小得多，而且所有的合成关联规则又可以由此导出，所以不丢失信息，又可以按照用户的兴趣只导出感兴趣的规则。
Quantum devices have very outstanding predominance , their high - speed high - frequency high - integrated and low - power characteristic , make them the very important devices in the use of vlsi in the future : this dissertation designed the binary nand gate and nor gate based on rt quantum devices 而量子器件在这方面有着非常明显的优势，它以其固有的超高速、超高频、超高集成度、高效低功耗等特点，在未来vlsi方面有着及其重要的应用前景，将成为21世纪信息技术的支柱。
Then introduce the embedded gis hardware infrastructure , and using two level of flash storage system to store different kinds of files . the theory of journal file system is introduced and a journal file system for nand flash chip is designed under for linux kernel 本文首先全面分析了嵌入式gis的研究现状、技术背景、面临的问题；然后提出了一个低成本嵌入式gis系统的硬件设计方案，该方案使用了两级flash的存储模式来存储不同类型的文件；接下来阐述了了日志文件系统的基本原理，并且在此基础上设计了一个linux平台下适用于nand芯片的日志文件系统。
