L1-Introduction to embedded system
嵌入式软件开发设计说明范文
嵌入式软件开发设计说明范文英文版Embedded Software Development Design Specification Template1. IntroductionThis document provides a detailed design specification for the development of an embedded software system. The purpose of this specification is to ensure a clear understanding of the requirements, architecture, and implementation details among the development team, stakeholders, and other interested parties.2. System OverviewThe embedded software system is designed to power a smart sensor node for environmental monitoring. It collects data such as temperature, humidity, and pressure from various sensors and transmits it wirelessly to a central server for analysis and storage.3. Software RequirementsFunctional Requirements:Collect data from sensors accurately.Transmit data wirelessly to the central server.Have the ability to configure sensor settings remotely.Non-functional Requirements:Low power consumption.High data transmission reliability.Secure communication.4. System ArchitectureThe embedded software system consists of three main components: sensor interface module, communication module, and control module.Sensor Interface Module: Responsible for interacting with the physical sensors, acquiring data, and preprocessing it.Communication Module: Handles wireless data transmission to the central server using a suitable communication protocol.Control Module: Manages the operation of the system, coordinates data flow between modules, and implements remote configuration functionality.5. Software DesignModule Interaction: Modules will communicate with each other using inter-module messages and shared memory segments.Data Structures: Defined data structures will be used to efficiently store and transmit sensor data.Algorithms: Algorithms for data preprocessing and wireless transmission will be optimized for speed and efficiency.6. Implementation DetailsProgramming Language: The system will be implemented using C/C++ for its efficiency and portability.Hardware Considerations: The software design will take into account the limitations and capabilities of the target hardware platform.Testing: Rigorous testing including unit testing, integration testing, and system testing will be conducted to ensure the software meets the specified requirements.7. ConclusionThis design specification outlines the requirements, architecture, and implementation details for the development of an embedded software system for environmental monitoring. It serves as a guide for the development team to ensure a smooth and efficient development process.中文版嵌入式软件开发设计说明范文1. 引言本文档为嵌入式软件系统的开发提供了一份详细的设计说明。
第2章信息与通信工程专业英语(第2版)_韩定定
Signal Processing
New Words and Expressions
algorithm n. 算法 n. 声纳 ，声波定位仪 心电图 傅立叶变换 adj.可编程的 多路复用技术 n.放大器 n.传感器，变频器
Lesson One
Modern Digital Design & Digital Signal Processing
比较而言，DSP可以将音频信号转变为数 据流。由于数字比特易于组合与分离，因 There are approximately one billion 此，多路电话信号可以通过一条信道实现 telephones in the world. At the press of a 传输，这种技术称为复用。 few buttons, switching networks allow Lesson One any one of these to be connected to any Modern Digital Design & other in only a few seconds. … In Digital comparison, DSP converts audio signals Signal Processing into a stream of serial digital data. Since bits can be easily intertwined and later Text A separated, many telephone conversations Introduction to Digital can be transmitted on a single channel. Signal Processing This technology is called multiplexing.
英语面试自述
Self-introduction 1 Good morning! Professors:I’m very glad to be here for this interview, and I hope I can make a good performance today.My name is SuYing, I come from college of public administration of Hunan Normal university. My major is politics science and administration, the major for father education that I pursue here is politic theory.I like my major very much. And I have got top scores in our grand. During the past three years, I studied political science, administrative science, international politics, and law. I possess such abilities below: political research, public policy analysis, social surveys and statistics. During my university life, I once designed a questionnaire on youth volunteer in universities of Hunan, and wrote a report, which got the second award of my college this year. I did an investigation on commerce of village in the city, the survey report of which has been published. The study in my major also gave me a macro, rational thinking habit, and a more professional perspective on social problems, because of which, I have written 100,000 words on my blog, which has got 25 articles published in the internet ,books or newspapers.About practice, I am always proud as a youth volunteer. I was a head of the youth volunteer association of my college. During the university time, I organized and participated nearly 30 activities. In addition, this summer I worked in a community for about 1 month. Thanks to those experiences, I used my knowledge in real affairs and increased my abilities in realated aspects.Recently, I am interested in political communication and political culture. If I can be a postgraduate of china politics and Law University, I hope I can do specific and deep study on those aspects.That’s all. Thanks for your attentio ns.Self-introduction 2My name is SuYing, I come from college of public administration of Hunan Normal university. My major is politics science and administration, the major for father education that I pursue here is politic theory.I like my major very much. During the past three years , I have got top scores in our grand.I once did some investigation on social problems . But I think the most important things that study in my major gave me are a macro, rational thinking habit, and a more professional perspective on social problems, because of which, I have written 100,000 words , which has got nearly 30 articles published in the books or newspapers.About my life , I like painting ,skating ,reading ,surfing the internet and so on. In addition ,I am always proud as a youth volunteer. In my spare time ,I often go to the communities to look after oldmen or children there.In a word, I think I have got a wonderful university lift during the past there years. And I hope I can make much progress in my future. So today I’m sitting here , I hope I could be the postgraduate of this famous university.Good afternoon (morning), professors：It is my great pleasure to be here. My name is mingmingzhou , graduated from Computer Science Department of Wuhan University.During my four-year study in the university as an under-graduate student, I have built up a solid foundation of professional knowledge, as well as a rich experience of social activities. I am a determined person, always willing to achieve higher goals.What's more, I am good at analysis, with a strong sense of cooperation. All of these led me to the success of passing the first round of the entrance examination to the Master's degree. Personally, I am very humorous and easy-going, enjoying a good relationship among my classmates.In my spare time, I like to read books regarding how to be myself and how to deal with problems. Music and movies are my favorite entertainments. As for my sport interest, I could not deny my greatest interest is football. Playing this game brings me a lot of glory, happiness and passion.All in all, Wuhan University, with a highly qualified faculty and strong academic environment is the university I have long admired. I believe that I am a very qualified applicant for admission into your Master of IT program and can contribute to the enrichment or diversity of your university.THANK YOU FOR YOUR ATTENTION！第一篇：professors：It is my great pleasure to be here. My name is **** , graduated from ****Department of **** University.During my four-year study in the university as an under-graduate student, I have built up a solid foundation of professional knowledge, as well as a rich experience of social activities. I am a determined person, always willing to achieve higher goals. Whats more, I am good at analysis, with a strong sense of cooperation. All of these led me to the success of passing the first round of the entrance examination to the Masters degree. Personally, I am very humorous and easy-going, enjoying a good relationship among my classmates. In my spare time, I like to read books regarding how to be myself and how to deal with problems. Music and movies are my favorite entertainments. As for my sport interest, I could not deny my greatest interest is football. Playing this game brings me a lot of glory, happiness and passion. All in all, Wuhan University, with a highly qualified faculty and strong academic environment is the university I have long admired. I believe that I am a very qualified applicant for admission into your Master of IT program and can contribute to the enrichment or diversity of your university. THANK YOU FOR YOURATTENTION！第二篇：Good morning. I am very glad to be here for this interview.2.姓名，英文名，毕业院校，毕业专业，毕业学院First let me introduce myself. My name is LiShuai, and my English name is Jacky Lee. I've finished my undergraduate education in Xidian University, Majoring in Electronic Science and Technology in the college of Technical Physics.3.性格，爱好，实践经验I am open-minded, willing and have broad interests like basketball, reading and especially in engineering such as software programming, website design, hardware design. For example, during the past four years, I have accomplished two websites: one is the website of our school, and the other is the website of the doctor forum of china 2007. Furthermore, I am interested in C plus plus programming language and have written some application programs. In July in the last year,I finished my graduate project with flying colors,which was a software application about Image Process . In addition, I have also finished some projects about embedded system by using MCU when I was a junior.4.为什么想读研,将来愿意从事的方向,读研时的打算Although I have broad interests in many aspects and grasp the essential knowledge of the major, but I think at present, I can do many things in a superficial level, but not be competent to do things professionally owing to lack of ample knowledge and ability.So I think further study is still urgent for me to realize self-value.The major that I hope pursue for my further education is IC design. Because I find integrated circuits are playing a more and more important role in our modern society. And nowadays in China, with the recognition by the government, our domestic integrated circuits industry is growing rapidly and that may provide a lot of chances to us.I plan to concentrate on study and research in this field in my graduate time. And I hope I can form a systematic view of micro electronics and IC design technology and make a solid foundation for future profession after three years study here.5.结束语OK, that’s all. Thank you very much第三篇Good morning. I am glad to be here for this interview. First let me introduce myself. My name is ***, 24. I come from ******,the capital of *******Province. I graduated from the ****** department of *****University in July ,2001.In the past two years I have been prepareing for the postgraduate examination while I have been teaching *****in NO.****middle School and I was a head-teacher of a class in junior grade two.Now all my hard work has got a result since I have a chance to be interview by you.I am open-minded ,quick in thought and very fond of history.In my spare time,I have broad interests like many other youngers.I like reading books, especially those ****.Frequently I exchange with other people by making comments in the forum on line.In addition ,during my college years,I was once a Net-bar technician.So, I have a comparative good command of network application.I am able to operate the computer well.I am skillful in searching for information in Internet.I am a football fan for years.Italian team is my favorite.Anyway,I feel great pity for our country’s team.I always believe that one will easily lag behind unless he keeps on learning .Of course, if I am given a chance to study ****** in this famous University,I will stare no effort to master a good command of advance ******.第四篇Hello, my professors.It's a fine day today,and i'm very pleased to meet you here.First of all,i'd like to introduce myself to you.My name is ***,my hometown is ***,which is a really beautiful city.Even when i was a young boy,i was very interested in biology science.Every one may have a dream,and i still remember that my dream is to be a biology scientist (just like ZHU KE ZHEN).I liked to make wonders just like,where are we from?Where are we going in the universe?And then i would find the answers in book by myself.Still today i think that interest is the best teacher in one's whole life (and knowledge comes from practice).Second, i will introduce my major in the university.My major is Biological Engineering in *** University.It has a great relationship with biology scince.Their relationship can be shown with an example: Just like a river,biology science,whichoften finds new discoveries and theories, is at the head of the river.And my major,which lays more stress on practical use, seems to be at the end of it.When both of them interact well enough,the discovries and theories in biology science can be soon turned into products in all of the modern industry.Four years' university education gives me a lot of things to learn,a lot of chances to try,and a lot of practices to improve myself.It teaches me not only what to study and how to think,but also to see the importance of practical ability (such as doing expriment as much as possible). In the university life,i have made many good friends.They help me improve my study and research ability, do ererything just like a man,and often give me good example to follow.Besides what i have introduced myself above,i also have many interests in my spare time.I like playing football,which is an effective way i think to improve my body health,and it can teach me how to join in a group and deal with other people.Drawing and writing is another favor to me.Above all,i choose the major in order to broad my view in biology scince,and enhance my research ability.I will do my best to join the new group and be good at postgraduate study.第五篇Hello, my name is ***, it is really a great honor to have this opportunity for a interview, i would like to answer whatever you may raise, and i hope i can make a good performance today, eventually enroll in this prestigious university in september. now i will introduce myself briefly,i am **years old,born in ***8 province ,northeast of china,and i am curruently a senior student at ****.my major is packaging engineering.and i will receive my bachelor degree after my graduation in june.in the past *years,i spend most of my time on study,i have passed ****with a ease. and i have acquired basic knowledge of packaging and publishing both in theory and in practice. besides, i have attend several packaging exhibition hold in Beijing, this is our advantage study here, i have taken a tour to some big factory and company. through these i have a deeply understanding of domestic packaging industry. compared to developed countries such as us, unfortunately, although we have made extraordinary progress since 1978,our packaging industry are still underdeveloped, mess, unstable, the situation of employees in this field are awkard. but i have full confidence in a bright future if only our economy can keep the growth pace still. i guess you maybe interested in the reason itch to law, and what is my plan during graduate study life, i would like to tell you that pursue law is one of my lifelong goal,i like my major packaging and i wont give up,if i can pursue my master degree here i will combine law with my former education. i will work hard inthesefields ,patent ,trademark, copyright, on the base of my years study in department of p&p, my character? i cannot describe it well, but i know i am optimistic and confident. sometimes i prefer to stay alone, reading, listening to music, but i am not lonely, i like to chat with my classmates, almost talk everything ,my favorite pastime is valleyball,playing cards or surf online. through college life,i learn how to balance between study and entertainment. by the way, i was a actor of our amazingdrama club. . Thank you.第六篇Good afternoon (morning), professors：It is my great pleasure to be here. My name is mingmingzhou , graduated from Computer Science Department of Wuhan University.During my four-year study in the university as an under-graduate student, I have built up a solid foundation of professional knowledge, as well as a rich experience of social activities. I am a determined person, always willing to achieve higher goals.What's more, I am good at analysis, with a strong sense of cooperation. All of these led me to the success of passing the first round of the entrance examination to the Master's degree. Personally, I am very humorous and easy-going, enjoying a good relationship among my classmates.In my spare time, I like to read books regarding how to be myself and how to deal with problems. Music and movies are my favorite entertainments. As for my sport interest, I could not deny my greatest interest is football. Playing this game brings me a lot of glory, happiness and passion.All in all, Wuhan University, with a highly qualified faculty and strong academic environment is the university I have long admired. I believe that I am a very qualified applicant for admission into your Master of IT program and can contribute to the enrichment or diversity of your university.THANK YOU FOR YOUR ATTENTION！。
摩抬DA-820系列3U19英寸IEC 61850本地PRP HSR计算机产品介绍说明书
DA-820Series3U19-inch IEC61850native PRP/HSR computers with Intel®Celeron®,Core™i3or i7 CPUFeatures and Benefits•IEC61850-3,IEEE1613,and IEC60255compliant for power substationautomation systems•Intel®Core™Celeron,i3,and i7CPU and QM77chipset•1CFast slot for OS and4SATA III for storage expansion(support Intel®RSTRAID0/1/5/10)•6USB2.0ports for high-speed peripherals•3PCIe x1slots and2PCI slots for expansion modules•1PCIe x16slot for an additional video card•Highly reliable design,supporting dual power and PRP/HSR technology(withPRP/HSR expansion module)•Onboard TPM module for enhanced cybersecurityCertificationsIntroductionThe DA-820is based on the Intel®Celeron™/Intel®Core™i3,and i7CPU and QM77chipset,which supports the standard x86OS and comes with 2VGA ports,6USB ports,4Gigabit LAN ports,and23-in-1RS-232/422/485serial ports.The DA-820is equipped with a4SATA disk interface and supports RAID0/1/5/10functionality.The DA-820is specifically designed for substation applications that require precise time synchronization and adherence to the IEC61850-3standards.The flexible design makes the DA-820suitable for local SCADA,environmental monitoring,video surveillance,protocol conversion,and PRP/HSR redundancy applications.In addition,the cybersecurity functions make the DA-820an ideal solution for secure network communication applications.The DA-820complies with the IEC60255standards to enable the protection of electrical relays in a smart substation.IEC60255is one of the most widely used standards for testing relays and protection equipment,and compliance ensures that the DA-820will work reliably and seamlessly with IEDs(intelligent electronic devices)as a part of the robust substation automation system.The housing is a standard3U,19-inch wide,rack-mountable rugged enclosure.This robust,rack-mountable design provides the hardened protection needed for industrial environment applications.Smart Recovery FunctionThe DA-820’s Smart Recovery function makes it easy to troubleshoot system software errors on computers to minimize downtime.Engineers who are experts in a particular vertical market may not have enough computer domain knowledge to know how to fix the operating system problems. Moxa Smart Recovery™is an automated BIOS-level recovery system tool that allows engineers to automatically trigger OS recovery to minimize downtime.Proactive Monitoring FunctionMoxa Proactive Monitoring is a small-footprint,resource-friendly,easy-to-use utility that allows users to track a number of system parameters. Users can view the current parameter values for these key parts by simply clicking on the icons corresponding to the parameters in the user er-defined key part indicators(KPIs)are used to monitor the computer’s key parts.Visible and/or audio alerts are triggered automatically via relay and SNMP traps when these KPIs exceed their preset threshold values,making it extremely convenient for operators to avoid system downtime by setting up predictive maintenance tasks well in advance.AppearanceFront View Rear ViewSpecificationsComputerCPU DA-820-C1Series:Intel®Celeron®Processor1047UE(2M cache,1.40GHz)DA-820-C3Series:Intel®Core™i3-3217UE Processor(3M cache,1.6GHz)DA-820-C7Series:Intel®Core™i7-3555LE Processor(4M cache,up to3.20GHz)DA-820-C8Series:Intel®Core™i7-3612QE Processor(6M cache,up to3.10GHz) System Chipset Mobile Intel®QM77Express ChipsetGraphics Controller Intel®HD Graphics4000(integrated)System Memory Slot SODIMM DDR3/DDR3L slot x2DRAM16GB max.capacity(204-pin SODIMM x2,each supporting unbuffered ECC DDR3memory at1333and1600MT/s and8GB maximum per module)Supported OS Windows7Pro for Embedded SystemsWindows Embedded Standard7(WS7P)64-bitLinux Debian7Note:OS available by CTOSStorage Slot 2.5-inch HDD/SSD slots x4CFast slot x1Computer InterfaceEthernet Ports Auto-sensing10/100/1000Mbps ports(RJ45connector)x4Serial Ports RS-232/422/485ports x2,software selectable(DB9male)USB2.0USB2.0hosts x6,type-A connectorsExpansion Slots PCIe x1slots x3PCIe x16slot x1PCI slots x2Video Input VGA x2,15-pin D-sub connector(female)LED IndicatorsSystem Power x1Storage x1Programmable x8LAN8per port(10/100/1000Mbps)Serial2per port(Tx,Rx)Serial InterfaceBaudrate50bps to115.2kbpsConnector DB9maleESD8kV(level4)Isolation2kVSerial Standards RS-232/422/485Surge2kVSerial SignalsRS-232TxD,RxD,RTS,CTS,DTR,DSR,DCD,GND RS-422Tx+,Tx-,Rx+,Rx-,GNDRS-485-2w Data+,Data-,GNDRS-485-4w Tx+,Tx-,Rx+,Rx-,GNDPower ParametersPower Button Reset button(front panel)ON/OFF(rear panel)Power Consumption60W(max.)Physical CharacteristicsHousing MetalDimensions(without ears)361x440x133mm(14.23x17.32x5.24in) Weight14,000g(31.11lb)Installation19-inch rack mountingEnvironmental LimitsOperating Temperature Standard Models:-40to60°C(-40to140°F)Wide Temp.Models:-40to75°C(-40to167°F) Storage Temperature(package included)-40to85°C(-40to185°F)Ambient Relative Humidity5to95%(non-condensing)Standards and CertificationsEMC EN61000-6-2/-6-4EMI CISPR32,FCC Part15B Class AEMS IEC61000-4-11DIPsIEC61000-4-2ESD:Contact:8kV;Air:15kVIEC61000-4-3RS:80MHz to1GHz:10V/mIEC61000-4-4EFT:Power:4kV;Signal:4kVIEC61000-4-5Surge:Power:4kV;Signal:4kVIEC61000-4-6CS:10VIEC61000-4-8:20A/mPower Substation IEC61850-3,IEEE1613Protection Relay IEC60255Safety EN60950-1,IEC60950-1,UL60950-1Shock IEC60068-2-27,IEC60870-2-2,IEC61850-3Edition1.0 DeclarationGreen Product RoHS,CRoHS,WEEEMTBFTime DA-820-C1-SP-HV-T:193,537hrsDA-820-C1-DP-HV-T:222,207hrsDA-820-C1-SP-LV-T:283,281hrsDA-820-C1-DP-LV-T:288,116hrsDA-820-C3-SP-HV-T:193,537hrsDA-820-C3-DP-HV-T:222,207hrsDA-820-C3-SP-LV-T:283,281hrsDA-820-C3-DP-LV-T:288,116hrsDA-820-C7-SP-HV-T:191,570hrsDA-820-C7-DP-HV-T:219,618hrsDA-820-C7-SP-LV-T:240,015hrsDA-820-C7-DP-LV-T:285,508hrsDA-820-C8-SP-HV:172,182hrsDA-820-C8-DP-HV:194,509hrsDA-820-C8-SP-LV:240,015hrsDA-820-C8-DP-LV:285,508hrsWarrantyWarranty Period3yearsDetails See /warrantyPackage ContentsDevice1x DA-820Series computerInstallation Kit1x rack-mounting earDocumentation1x quick installation guide1x warranty cardNote This product requires additional modules(sold separately)to function. DimensionsOrdering InformationDA-820-C8-SP-HV i7-3612QE Single✓–-40to60°C DA-820-C8-DP-HV i7-3612QE Dual✓–-40to60°C DA-820-C8-SP-LV i7-3612QE Single–✓-40to60°C DA-820-C8-DP-LV i7-3612QE Dual–✓-40to60°C DA-820-C7-SP-HV i7-3555LE Single✓–-40to60°C DA-820-C7-SP-HV-T i7-3555LE Single✓–-40to75°C DA-820-C7-DP-HV i7-3555LE Dual✓–-40to60°C DA-820-C7-DP-HV-T i7-3555LE Dual✓–-40to75°C DA-820-C7-SP-LV-T i7-3555LE Single–✓-40to75°C DA-820-C7-DP-LV-T i7-3555LE Dual–✓-40to75°C DA-820-C3-SP-HV-T i3-3217UE Single✓–-40to75°C DA-820-C3-DP-HV-T i3-3217UE Dual✓–-40to75°C DA-820-C3-SP-LV-T i3-3217UE Single–✓-40to75°C DA-820-C3-DP-LV-T i3-3217UE Dual–✓-40to75°C DA-820-C1-SP-HV-T Celeron1047UE Single✓–-40to75°C DA-820-C1-DP-HV-T Celeron1047UE Dual✓–-40to75°C DA-820-C1-SP-LV-T Celeron1047UE Single–✓-40to75°C DA-820-C1-DP-LV-T Celeron1047UE Dual–✓-40to75°C Accessories(sold separately)Expansion ModulesDA-IRIG-B-S-02-T IRIG-B expansion module,PCI interface,1fiber IRIG-B in,1DB9M in/out,1DB9M outDA-IRIG-B-S-04-T IRIG-B expansion module,PCI interface,1fiber IRIG-B in,1DB9M in/out,3DB9M outDA-PRP-HSR2-port Gigabit Ethernet expansion module compliant with IEC62439-3protocol for DA-820Seriesindustrial computersDE-GX02-SFP-T2-port1000Mbps fiber card,SFP slot x2,PCIe interface(SFP module excluded)DE-FX02-SFP-T2-port100Mbps fiber card,SFP slot x2,PCIe interface(SFP module excluded)CablesCBL-RG58AUBNCMF9-150DB9female to BNC male cable for the DA-IRIG-B-S-02-T and DA-IRIG-B-S-04-T,1.5m ConnectorsMini DB9F-to-TB DB9female to terminal block connectorStorage KitsFAN-KIT-82001DA-820HDD/SSD kit with heat dissipation vent for heat dispatch and lock for securityFAN-KIT-82002DA-820HDD/SSD kit with heat dissipation vent for heat dispatch(lock not included)HDD-DOOR-LOCK-82001DA-820HDD/SSD kit with lock for securityUSB Dongle KitsUSB Dongle Kit Internal USB dongle kit installation packageThermal KitsDDR3-THERMAL-KIT-82001DDR3SDRAM thermal kit©Moxa Inc.All rights reserved.Updated Dec16,2019.This document and any portion thereof may not be reproduced or used in any manner whatsoever without the express written permission of Moxa Inc.Product specifications subject to change without notice.Visit our website for the most up-to-date product information.。
内存压缩技术介绍（Memorycompressiontechnologyintroduced）
内存压缩技术介绍（Memory compression technology introduced）Abstract: This paper introduces the memory compression technology and a hardware memory compression system model based on the application of memory compression technology in embedded system; introduced hardware memory compression system and operating system support for memory compression mechanism; introduce memory pressure Lempel-Ziv algorithms commonly used in shrinkage, and discusses the application problems memory compression technology in embedded system.Keywords: embedded system, memory compression, memory controller, Lempel-Ziv algorithm1 memory compression technology introducedIn order to save storage space or transmit bandwidth, data compression technology has been widely used in computer systems. When a magnetic medium stores data or a network transmits data, people use a variety of compression techniques based on hardware or software. While compression technology is popular in all fields, memory compression technology has not been widely used because of its complexity. In recent years, memory compression techniques have become feasible due to advances in parallel compression, decompression algorithms, and advances in silicon density and speed.The main idea of memory compression technology is to compress data into compressed memory according to a certain algorithm. The system can find compressed data from compressed memory, and then decompress it for the system to use. This will increase the available memory space and reduce the overhead of pagereplacement, so as to improve the overall performance of the system at a relatively small cost.The memory compression mechanism adds a layer of logic to the storage hierarchy of the system -- compressing the memory layer. In this layer, the system stores the physical pages in a compressed format. When the page is referenced by the system again, it can be used after decompressing the compressed page. We will manage the compressed memory layer of related hardware and software collection, collectively known as memory compression system. Memory compression systems are transparent to CPU, I/O devices, device drivers, and application software, but the operating system must have the ability to manage memory size changes as well as compression ratio changes.For most operating systems, most memory architectures do not need to be changed to achieve memory compression. In standard operating systems, memory is represented by a fixed number of physical page frames (page, frame) that are managed by the VMM of the operating system. To support memory compression, the actual memory size and number of page frames to be managed by OS are determined based on the memory compression ratio. Here the memory refers to the memory size of the operating system, following its relationship with physical memory: if PM is the physical memory, RM (T) is the actual memory time in T system, and CR (T) is the compression ratio, the maximum of real memory at a given time t support for RM (t =CR1 (T) * PM). However, due to the application of the data compression rate is not dependent on OS and the dynamic change, uncompressed data may run out of physical memory, so when physical memory is nearly exhausted, the operating system must take action to solve thisproblem.2 memory compression system hardware modelAt present, more and more people pay attention to memory compression, and some software based memory compressors have appeared in the market. These memory compressors mainly compress data through software, but because of the delay of accessing compressed data, it is not obvious in the improvement of system performance, and some even reduce system performance. This section introduces a hardware based memory compression system model.Figure 1 is a typical memory compression system hardware model, including compressed memory, L3 cache, compressed memory controller and other hardware components.Compressed memory (133MHz SDRAM) contains compressed data. L3 cache is a shared, 32MB, 4 way group associative, write back cache, each line size of 1KB, made up of two times data rate (DDR) SDRAM. L3 cache contains uncompressed buffer rows, and because most of the accesses can hit in the L3 cache, it hides the latency caused by accessing compressed memory. L3 cache is the main memory for the upper layer in the storage hierarchy, and its operations are transparent to other hardware, including processors and I/O. The compressed memory controller is the control center of the whole memory compression system, which is responsible for data compression / decompression, monitoring the use of physical memory, and the actual address to physical address addressing process.The data compression process is like this: compressed memory control compresses the 1KB cache rows into compressed memory and reads them out of compressed memory. Its compression algorithm is the Lempel-Ziv algorithm, we will introduce this algorithm in the next section. The compression mechanism stores the compressed data blocks in different length formats into memory. The storage unit for compressed memory is a 256 byte region. Different according to compression ratio,A 1KB memory block (just the size of each line of L3) can occupy 0~4 compressed regions.The compressed memory controller must translate the actual address on the system bus into the physical address in the physical memory according to the length format. The actual address is the normal address that appears on the processor's external bus. Huangyuan address used to record ten 256 bytes of memory compression area. The actual address space exists in the L1/L2/L3 cache for immediate access. The rest of the memory content exists in physical memory as compressed. The memory controller performs translation from the actual address to the physical address by querying the compressed translation table (CTT), which is kept at a location in the physical memory. Figure 2 is the format of the CTT table and the addressing mode of the memory controller.The actual address of each 1KB memory block is mapped to an item of CTT, while the CTT has a total of 16 bytes each, including four physical area addresses, each pointing to the physical memory and listening to a 256 byte region. For blocks less than 120 bits, such as an all zero block, we use a special CTT formatcalled a generic row format. In this format, the compressed data is all stored in the CTT entry instead of the four address pointer. Thus, a 1KB generic block occupies only 16 bytes of physical memory, with a compression ratio of 64:1.In a compressed memory controller, a series of registers are used to monitor physical memory usage. Sectors Used Register (SUR) reports compressed memory usage to the operating system. The, Sectors, Used, Threshold, Registers, SUTHR, and SUTLR are used to set the point of entry for memory exhaustion. The SUTLR register is the entrance to the PCI interrupt circuit INTA, and the SUTHR register is the gateway to the NMI interrupt. When the SUR exceeds the value of SUTLR, the memory controller generates an interrupt, and the operating system takes steps to prevent memory consumption.In a translation from the actual address to the physical address, a useful method is fast page manipulation. It allows the controller to modify only four pointers to the CTT item, so that the contents of the 4KB page can be swapped out or emptied. The quick page operation clears all of the contents of the 4KB page by modifying all the CTT items associated with the 4KB page to the common line format (that is, all zeros). Similarly, a pair of pages can exchange page content by exchanging their regional pointers to related CTT items. With no large amount of data movement occurring, fast pages are operating at a fairly rapid rate.The compression / decompression function of the compressed memory controller is based on the LempelZiv algorithm, so the next section gives a brief introduction to the idea of thealgorithm.3 memory compression algorithm Lempel-ZivThe vast majority of compression algorithms, including the particularly popular Lempel-Ziv compression algorithms, are based on the full repetitive detection of strings of atomic (Token) strings. Although this algorithm is not the best algorithm, but the Lempel-Ziv algorithm emphasizes the simplicity of the algorithm and the rate of achieving high compression rates, so it is still widely used in memory compression.The Lemple-Ziv algorithm (LZ) encodes a bit string into phrases, and then describes the stream as a series of pairs. Each pair makes up a new phrase, which contains a number (the identifier of the previous phrase) and a bit (appended to the previous phrase). This encoding is very large, but once applied to a suitable string, it is a fairly efficient encoding. Here's an example of how the algorithm is encoded.+ + (010++1=0101) U=0010001101, said the connection string is not compressed. C is a compressed string. P (x) stands for the number of phrases X. Take a look at U=0010001101 first and find that it can be written as U=0++010001101, so that P (1) =P (0) ++0 is obtained. Now continue to write it as U=0++02++0001101, and you can get P (2) =P (1) ++1. We have now described P (2) as a combination of the last phrase and a new bit. Next,U=0++01++00++01101, and get P (3) =P (1) ++0. Now we notice that there are U=0++01+00+011++01, and P (4) =011=P (2) ++1, and finally P (5) =P (1) ++1. The steps of the operation are listedin table 1.Once you have created table 1, you have the entire coded chart. To create the Lempel-Ziv data stream, you create the following formula. If the formula is P (x) =P (A) ++B, each pair is (A++B). Therefore, P (1) =P (0) ++0 becomes (00++0), P (2) =P (1) ++0 becomes (01++0), and so on, all these pairs are connected, and the final string is obtained, as shown in table 2. In this way, C becomes 000011010101011, and looks much longer than U. But because of the short length of the U, the advantage can not be seen, and the formula containing P (0) is not compressed,So it also causes an increase in length.Lempel-Ziv string decoding is very simple, that is, seize the pair, the control table 1 for reconstruction.Table 1 encoding processStep value formula U0 - P (0) 001000110110 P (1) =P (0) ++0 0++010001101201 P (2) =P (1) ++1 0++01++00++01101300 P (3) =P (1) ++0 0++01++00++011014011 P (4) =P (2) ++1 0++01++00++011++01501 P (5) =P (1) ++1 0++01++00++011++01Table 2 how to create a coded stringFormula P (0) ++0 P (2) =P (1) ++1 P (3) =P (1) ++0 P (4) =P (2) ++1 P (5) =P (1) =P (1) ++1Yes, 00++0=000, 01++1=011, 01++0=010, 10=++1=101, 01++1=011C000++011++010++101++011=0000110101010114 operating system support for memory compressionIn a compressed memory system, memory size refers to the actual memory size, which is larger than physical memory. At boot time, the memory size reported by the BIOS to the operating system is greater than the actual installed physical memory. For example, the hardware prototype is installed with 512MB's SDRAM, but the memory size reported by the BIOS to the operating system is 1GB. When the application data is compressed at 2:1 or higher, the actual memory operates the same way as the memory operations of the general operating system. But when the application in uncompressed data to fill the memory (such as a zip file can not achieve the compression ratio of 2:1), due to the general OS only to see the actual address space, so be aware of the physical memory has been exhausted. For example, an operating system has an actual memory of 1024MB and a priest memory of 512MB. At this point, the actual memory has been allocated 600MB, and the system displays the free memory of the 424MB. However,since the memory compression rate has been low, the physical memory usage has been close to 512MB. If you allocate memory further, then the system crashes because the physical memory is exhausted, although it still shows the free memory of the 424MB. In this case, the operating system must provide support for managing compressed memory.Since memory compression is a relatively new concept, there is no such mechanism in general for systems to distinguish between actual addresses and physical addresses and can not handle physical memory exhaustion. However, as long as you make some minor changes to the operating system kernel, or add a device driver on top of the operating system, you can achieve the goal.Generally speaking, compressed memory should be managed from the following aspects.(1) monitor physical memory usageView the use of physical memory by polling or interrupt, and give warning before physical memory is exhausted. Compressed memory management routines are to compress physical memory by monitoring some registers in the memory controller. SUR reports the use of physical memory, and SUTHR and SUTLR are used to set the interrupt threshold. The compressed memory management algorithm is based on four physical memory states, namely steady, acquire, danger and interrupt, whose critical value is mc_th_acquire<mc_th_danger<mc_th_interrupt.We can monitor by combining polling and interruption, and react to changes in physical memory usage. The wheel routine is passedby the clock interrupt, which reads the value of the SUR once every 10ms and compares it to the critical value set by the system. When the system is in the steady state, without taking any action; when using more than mc_th_acquire, nr_rsrv_pages should be increased to limit the memory allocation, but it did not cause the lack of memory; when using more than mc_th_danger, should be increased to nr_rsrv_pages caused by lack of memory, and cause the page allocator and replacement process to reclaim memory page, once entered into the state of physical memory management routines will wake up the replacement process memory recovery.(2) reclaiming memory and emptying the content of free pages to reduce usageTake the standard Linux kernel as an example, there are two major variables in the operating system to manage too little memory. These two variables are nr_free_pages and struct freepages. To check if memory is exhausted, check it before allocating memory.If (nr_free_pages<freepages.min) {* memory is too small, the recovery page.}Else{/* can be assigned.In the memory compression system, this function is accomplished by adding a new variable, nr_rsrv_pages. This turns the minimum number of free pages to: freepages.min"=freepages.min+nr_rsrv_pages".By dynamically adjusting the nr_rsrv_pages variables,Compressed memory management routines can artificially cause memory shortages, causing the replacement process to reclaim pages, which temporarily suspend the call process. The recovery memory includes reducing various buffers and replacing the process page on the disk. When the page returns to the free page pool, they are cleared. We can use the quick page manipulation mentioned earlier to reduce the overhead of empty page operations.(3) blocking the CPU cycle to reduce physical memory usageWhen the physical memory is used more than the threshold value of mc_th_interrupt, the controller interrupts the processor, adds nr_rsrv_pages further, and then the CPU blocker starts running. We also use interrupt mechanism based on polling mechanism, because interrupt mechanism is faster than polling mechanism. If the physical memory usage suddenly rises in the 10ms interval, the hardware interrupt detects this earlier than the polling routine. To make it more secure, we use CPUblocker to block the processes that cause physical memory usage. CPU blocker is a free thread, they can make CPU free. Because pages are replaced by disks, they operate at a machine speed, while physical memory usage can be accessed at memory speed, increasing in speed. When the memory usage continues toincrease, and the page also cannot alleviate, the process needs to be blocked. We'll start by CPUblocker to block CPU cycle until the paging mechanism can effectively reduce the use of physical memory. CPUblocker does not block interrupts, and every 40ms, it makes CPU so that other processes are starved to death.Application of 5 memory compression technology in embedded systemAn embedded system is a special computer system that is part of a larger system or device. Typically, an embedded system resides on the bottom board of a uniprocessor and its application is stored in ROM. In fact, all devices with digital interfaces - monitors, microwave ovens, VCRs, automobiles - all use embedded systems. Some embedded systems include an operating system called an embedded operating system. In order to meet the special requirements of embedded applications, embedded microprocessors although the function and standard microprocessor is basically the same, but compared with the industrial control computer, the embedded microprocessor has the advantages of small size, light weight, low cost, reliability, the memory is still a valuable resource, so the research has a certain application value of memory compression technology in embedded system in.The idea of memory compression has actually been embodied in some embedded operating systems. For example, in VxWorks, when one of the operating systems is downloaded to the target, one way is to store the bootstrap and VxWorks images in the ROM. To decompress it, copy it from ROM to RAM. This software basedcompression can save ROM space, but its boot process is relatively slow.More memory compression technology has been applied in ROM, but for RAM, the software compression technology based on memory, because of its access to the compressed data can cause delays and uncertainties will be for real time embedded system and cause. Therefore, like virtual memory technology, it has not been widely used in embedded systems.The memory compression system introduced in this article is hardware based. Under the same benchmark, the test results show that the system runs at 1.3 times faster than the standard system. If you want to achieve the same size of memory, the memory compression system hardware cost is lower than the cost of buying RAM, and the greater the memory, the more savings it costs, you can achieve half the price. Therefore, in the embedded system with extremely precious memory resources, it is of great value to implement hardware based memory compression system.epilogueThe memory compression system introduced in this paper is based on specialized hardware support, namely, L3 cache and memory controller. At present most of the above framework of Pentium hardware platform, you only need to do some small shoes to the operating system kernel, and increase the service or a device driver, you can complete this function. Due to the requirements of real-time embedded systems, real-time hardware memory compression technology can not affect system to increaseavailable memory at the same time based on the RAM hardware cost is relatively lower price, has a certain practical value.。
Procedia Computer Science
Unlocking the promise of mobile value-added services byapplying new collaborative business models Original ResearchArticleTechnological Forecasting and Social Change , Volume 77, Issue 4, May 2010, Pages 678-693Peng-Ting Chen, Joe Z. Cheng Show preview | Related articles | Related reference work articlesPurchase $ 41.95 602 Software performance simulation strategies for high-level embedded system design Original ResearchArticlePerformance Evaluation , Volume 67, Issue 8, August2010, Pages 717-739Zhonglei Wang, Andreas Herkersdorf Close preview | Related articles |Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractAs most embedded applications are realized in software, softwareperformance estimation is a very important issue in embedded system design.In the last decades, instruction set simulators (ISSs) have become anessential part of an embedded software design process. However, ISSs areeither slow or very difficult to develop. With the advent of multiprocessorsystems and their ever-increasing complexity, the software simulation strategybased on ISSs is no longer efficient enough for exploring the large designspace of multiprocessor systems in early design phases. Motivated by thelimitations of ISSs, a lot of recent research activities focused on softwaresimulation strategies based on native execution. In this article, we firstintroduce some existing software performance simulation strategies as well asour own approach for source level simulation, called SciSim , and provide adiscussion about their benefits and limitations. The main contribution of thisarticle is to introduce a new software performance simulation approach, callediSciSim (intermediate Source code instrumentation based Simulation), whichachieves high estimation accuracy, high simulation speed and lowPurchase $ 41.95implementation complexity. All these advantages make iSciSim well-suited for system level design. To show the benefits of the proposed approach, we present a quantitative comparison between iSciSim and the other discussed techniques, using a set of benchmarks.Article Outline1. Introduction2. Software performance simulation strategies2.1. Instruction set simulators2.2. Binary (Assembly) level simulation2.3. Source level simulation2.4. IR level simulation3. The SciSim approach for source level simulation3.1. Source code instrumentation3.2. Simulation3.3. Advantages and limitations of SciSim4. The iSciSim approach for performance simulation of compiler-optimized embedded software4.1. Intermediate source code generation4.2. Intermediate source code instrumentation4.2.1. Machine code extraction and mapping list construction4.2.2. Basic block list construction4.2.3. Static timing analysis4.2.4. Back-annotation of timing information4.3. Simulation4.3.1. Dynamic timing analysis4.3.2. Hardware and software co-simulation in SystemC5. Experimental results5.1. Source code vs. ISC5.2. Benchmarking SW simulation strategies 5.3. Dynamic cache simulation5.4. Simulation in SystemC6. Discussions and conclusions AcknowledgementsReferencesVitae603Computer anxiety and ICT integration in English classesamong Iranian EFL teachers Original Research ArticleProcedia Computer Science, Volume 3, 2011, Pages 203-209Mehrak Rahimi, Samaneh YadollahiClose preview | PDF (190 K) | Related articles | Related reference work articlesAbstract | ReferencesAbstractThe purpose of this study was to determine Iranian EFL teachers’ level of computeranxiety and its relationship with ICT integration into English classes and teachers’ personalcharacteristics. Data were collected from 254 Iranian EFL teachers by Computer AnxietyRating Scale, ICT integration rating scale, and a personal information questionnaire. Theresults indicated a positive relationship between computer anxiety and age; however,computer anxiety, gender, and experience of teaching were not found to be related. Aninverse correlation was found between computer anxiety and ICT integration. While ICTintegration correlated negatively with age and years of teaching experience, it was notfound to be related to gender.604An environmental decision support system for spatialassessment and selective remediation OriginalResearch ArticleEnvironmental Modelling & Software, Volume 26, Issue 6,June 2011, Pages 751-760Purchase$ 19.95Robert N. Stewart, S. Thomas Purucker Close preview | Related articles | Related reference work articles Abstract | Figures/Tables | ReferencesAbstractSpatial Analysis and Decision Assistance (SADA) is a Windows freewareprogram that incorporates spatial assessment tools for effective environmentalremediation. The software integrates modules for GIS, visualization,geospatial analysis, statistical analysis, human health and ecological riskassessment, cost/benefit analysis, sampling design, and decision support.SADA began as a simple tool for integrating risk assessment with spatialmodeling tools. It has since evolved into a freeware product primarily targetedfor spatial site investigation and soil remediation design, though itsapplications have extended into many diverse environmental disciplines thatemphasize the spatial distribution of data. Because of the variety of algorithmsincorporated, the user interface is engineered in a consistent and scalablemanner to expose additional functionality without a burdensome increase incomplexity. The scalable environment permits it to be used for both applicationand research goals, especially investigating spatial aspects important forestimating environmental exposures and designing efficient remedial designs.The result is a mature infrastructure with considerable environmental decisionsupport capabilities. We provide an overview of SADA’s central functions anddiscuss how the problem of integrating diverse models in a tractable mannerwas addressed.Article OutlineNomenclature1. Introduction2. Methods2.1. Sample design2.2. Data management and exploratory data analysis2.3. Spatial autocorrelation2.4. Spatial models3. Results 3.1. Scalable interfacing and decision support3.2. Risk assessment3.2.1. Human health risk3.2.2. Ecological risk3.3. Selective remedial design4. Discussion and ConclusionAcknowledgementsReferencesResearch highlights ► SADA is mature software for data visualization, processing, analysis, and modeling. ► User interface balances functional scalability and decision support. ► Widely used due to free availability and shallow learning curve . ► Integration of spatial estimation and risk tools allows for rich decision support. 605 CoDBT: A multi-source dynamic binary translator using hardware –software collaborativetechniques Original Research ArticleJournal of Systems Architecture , Volume 56, Issue 10,October 2010, Pages 500-508Haibing Guan, Bo Liu, Zhengwei Qi, Yindong Yang,Hongbo Yang, Alei LiangShow preview | Related articles | Related reference work articles Purchase $ 31.50606 An analysis of third-party logistics performance and service provision Original Research ArticleTransportation Research Part E: Logistics andTransportation Review , Volume 47, Issue 4, July 2011, Pages 547-570Chiung-Lin Liu, Andrew C. Lyons Purchase$ 41.95Show preview | Related articles | Related reference work articles 607 Intelligent QoS management for multimedia services support in wireless mobile ad hoc networks OriginalResearch ArticleComputer Networks , Volume 54, Issue 10, 1 July 2010, Pages 1692-1706Lyes Khoukhi, Soumaya Cherkaoui Show preview | Related articles | Related reference work articlesPurchase $ 31.50 608 Limit to improvement: Myth or reality?: Empirical analysis of historical improvement on threetechnologies influential in the evolution ofcivilization Original Research ArticleTechnological Forecasting and Social Change ,Volume 77,Issue 5, June 2010, Pages 712-729 Yu Sang Chang, Seung Jin Baek Show preview| Supplementary content| Related articles | Relatedreference work articlesPurchase $ 41.95 609An enhanced concept map approach to improving children’s storytelling ability Original Research ArticleComputers & Education , Volume 56, Issue 3, April 2011, Pages 873-884Chen-Chung Liu, Holly S.L. Chen, Ju-Ling Shih, Guo-Ting Huang, Baw-Jhiune Liu Show preview | Related articles | Related reference work articlesPurchase $ 24.95610Human –computer interaction: A stable discipline, a nascent science, and the growth of the longtail Original Research ArticleInteracting with Computers , Volume 22, Issue 1, January 2010,Pages 13-27Alan Dix Show preview | Related articles | Related reference work articlesPurchase$ 31.50 611Post-agility: What follows a decade of agility? Original Research ArticleInformation and Software Technology , Volume 53, Issue 5,May 2011, Pages 543-555Richard Baskerville, Jan Pries-Heje, Sabine MadsenShow preview | Related articles | Related reference work articlesPurchase $ 19.95612Confidentiality checking an object-oriented class hierarchy Original Research ArticleNetwork Security , Volume 2010, Issue 3, March 2010, Pages 16-20S. Chandra, R.A KhanShow preview | Related articles | Related reference work articlesPurchase $ 41.95 613 European national news Computer Law & Security Review , Volume 26, Issue 5, September 2010, Pages 558-563 Mark Turner Show preview | Related articles | Related reference work articlesPurchase $ 41.95 614 System engineering approach in the EU Test Blanket Systems Design Integration Original Research ArticleFusion Engineering and Design , In Press, CorrectedProof , Available online 23 February 2011D. Panayotov, P. Sardain, L.V. Boccaccini, J.-F. Salavy, F.Cismondi, L. Jourd’Heuil Show preview | Related articles | Related reference work articlesPurchase $ 27.95 615A knowledge engineering approach to developing mindtools for context-aware ubiquitouslearning Original Research ArticleComputers & Education, Volume 54, Issue 1, January 2010, Pages 289-297Hui-Chun Chu, Gwo-Jen Hwang, Chin-Chung Tsai Show preview | Related articles |Related reference work articles Purchase $ 24.95616“Hi Father”, “Hi Mother”: A multimodal analysis of a significant, identity changing phone call mediated onTV Original Research Article Journal of Pragmatics, Volume 42, Issue 2, February 2010,Pages 426-442Pirkko Raudaskoski Show preview | Related articles | Related reference work articlesPurchase $ 19.95 617Iterative Bayesian fuzzy clustering toward flexible icon-based assistive software for the disabled OriginalResearch ArticleInformation Sciences , Volume 180, Issue 3, 1 February 2010, Pages 325-340Purchase$ 37.95Sang Wan Lee, Yong Soo Kim, Kwang-Hyun Park,Zeungnam BienShow preview | Related articles | Related reference work articles 618 A framework of composable access control features: Preserving separation of access control concerns from models to code Original Research ArticleComputers & Security , Volume 29, Issue 3, May 2010, Pages 350-379Jaime A. Pavlich-Mariscal, Steven A. Demurjian, LaurentD. MichelShow preview | Related articles | Related reference work articlesPurchase $ 31.50 619 Needs, affect, and interactive products – Facets ofuser experience Original Research ArticleInteracting with Computers , Volume 22, Issue 5, September 2010, Pages 353-362Marc Hassenzahl, Sarah Diefenbach, Anja Göritz Show preview | Related articles | Related reference work articlesPurchase $ 31.50 620 An IT perspective on integrated environmental modelling: The SIAT case Original Research ArticleEcological Modelling , Volume 221, Issue 18, 10 September 2010,Pages 2167-2176P.J.F.M. Verweij, M.J.R. Knapen, W.P. de Winter, J.J.F. Wien, J.A. te Roller, S. Sieber, J.M.L. JansenShow preview | Related articles | Related reference work articlesPurchase $ 31.50。
Microcomputers notes
Prerequisites
Microcomputer Lab (EB 106)
2
CPE 323
LAB Session
on-line LAB manual Access cards Accounts
Lab Assistant: Joel Wilder Lab sessions
Embedded systems: structure and organization Applications Technology Trends Historical perspective
CPE/EE 421/521 Microcomputers
4
Embedded Computer Systems
CPE 323 Introduction to Embedded Computer Systems: Introduction
Instructor: Dr Aleksandar Milenkovic Lecture Notes
CPE 323
Syllabus
textbook & other references grading policy important dates course outline memory organization decoding combinatorial and sequential logic important for system architecture Introduction sessions Lab instructor CPE/EE 421/521 Microcomputers
数据库系统概念(database system concepts)英文第六版 第一章
Databa se Sy stem Concept s - 6th Edition
1 .3
©Silber schatz , Korth and S u dar
n Relational model (Chapter 2) n Example of tabular data in the relational model Columns
_____ Rows
Databa se Sy stem Concept s - 6th Edition
1 .10
©Silber schatz , Korth and S u dar
n Physical Data Independence – the ability to modify the physical schema without changing the logical schema l Applications depend on the logical schema l In general, the interfaces between the various levels and components should be well defined so that changes in some parts do not seriously influence others.
1 .5
©Silber schatz , Korth and S u dar
n Phys ical level : describes how a record (e.g., customer) is stored. n Logical level : describes data stored in database, and the relationships among the data. type instructor = record ID : string;
测控技术与仪器专业培养方案
西北工业大学本科生培养方案Northwestern Polytechnical UniversityUndergraduate Program专业名称Specialty 中测控技术与仪器Techniques and Instrumentations forMeasurement &Control英专业代码080401Specialty Code学院名称自动化学院College of Automation Section培养方案制定人签字蒋东方 2009年月日Signature of Program Designer院长签字 2009年月日Signature of Dean校长签字 2009年月日Signature of President西北工业大学Northwestern Polytechnical University测控技术与仪器专业本科培养方案Undergraduate Program for Specialty in Techniques and Instrumentations for Measurement & Control一、培养目标I. Educational Objectives培养德、智、体全面发展，具有系统、扎实的理论基础和在测控领域具有较宽广的专业知识、较强的英语语言能力和较强的工程实践能力，良好的人文素质和创新精神，测量与控制技术、精密仪器与机械方面具有特色，毕业生能在信息技术产业、科研部门、高等院校及其相关领域从事测量与控制技术和仪器与系统的研究、设计、集成与开发等方面的高级研究性及应用性人才。
The program is aimed at educating and training the students to develop thoroughly in ethics, intelligent, and physical practice. The students are expected to have systematic, solid theoretical knowledge in measurement and control technique field, good skills in using English and in solving engineering problems, excellent personality and strong motility in innovation. The students are expected to show special ability in measurement and control techniques, precision instrumentation and mechanic fields. The students are educated aiming at doing research, design, system integration, and product development work as advanced researchers or engineers in IT industry, research institute or university after graduation.二、培养要求II. Educational Requirements毕业生应获得以下几个方面的知识和能力1. 具有较扎实的数理基础；2. 掌握测量与控制领域的基本理论和方法；3. 具有研究测控领域理论问题和解决实际问题的能力；4. 了解测控领域的发展动态；5. 具有较强的英语语言能力；6. 掌握文献检索、资料查询的方法和撰写科学论文的能力；7. 具有较好的人文社科知识和人文素质，以及较强的协调、组织能力；8. 具有较强的创新精神。
14.1-Embedded elements
ABAQUS Analysis User's Manual20.4.1 Embedded elementsProducts: ABAQUS/Standard ABAQUS/Explicit ABAQUS/CAEReferences•“Kinematic constraints: overview,” Section 20.1.1•*EMBEDDED ELEMENT•“Defining embedded region constraints,” Section 15.13.6 of the ABAQUS/CAE User's ManualOverviewThe embedded element technique:•is used to specify an element or a group of elements that lie embedded in a group of host elements whose response will be used toconstrain the translational degrees of freedom of the embedded nodes(i.e., nodes of embedded elements);•can be used in geometrically linear or nonlinear analysis;•is not available for host elements with rotational degrees of freedom;•can be used to model a set of rebar-reinforced membrane, shell, or surface elements that lie embedded in a set of three-dimensionalsolid (continuum) elements; a set of truss or beam elements that lieembedded in a set of solid elements; or a set of solid elements thatlie embedded in another set of solid elements;•will not constrain rotational degrees of freedom of the embedded nodes when shell or beam elements are embedded in solid elements; and •can be imported from ABAQUS/Standard into ABAQUS/Explicit and vice versa.IntroductionThe embedded element technique is used to specify that an element or group of elements is embedded in “host” elements. The embedded element technique can be used to model rebar reinforcement. ABAQUS searches for the geometric relationships between nodes of the embedded elements and the host elements. If a node of an embedded element lies within a host element, the translational degrees of freedom at the node are eliminated and the node becomes an “embedded node.” The translational degrees of freedom of the embedded node are constrained to the interpolated values of the corresponding degrees of freedom of the host element. Embedded elements are allowed to have rotational degrees of freedom, but these rotations are not constrained by the embedding. Multiple embedded element definitions are allowed.Available embedded element typesDifferent element types can be used in the element set containing embedded elements and the element set containing the host elements. However, all the host elements can have only translational degrees of freedom, and the number of translational degrees of freedom at a node on the embedded element must be identical to the number of translational degrees of freedom at a node on the host element. The following general types of “embedded elements-in-host elements” are provided:•Two-dimensional models:•Beam-in-solid•Solid-in-solid•Truss-in-solid•Axisymmetric models:•Membrane-in-solid (ABAQUS/Standard only)•Shell-in-solid•Solid-in-solid•Surface-in-solid (ABAQUS/Standard only)•Three-dimensional models:•Beam-in-solid•Membrane-in-solid•Shell-in-solid•Solid-in-solid•Surface-in-solid•Truss-in-solidSpecifying the host elementsBy default, the elements in the vicinity of the embedded elements are searched for elements that contain embedded nodes; the embedded nodes are then constrained by the response of these host elements. To precludecertain elements from constraining the embedded nodes, you can define a host element set; the search will be limited to this subset of the host elements in the model. This feature is strongly recommended if the embedded nodes are close to discontinuities in the model (cracks, contact pairs, etc.).Input File Usage: *EMBEDDED ELEMENT, HOST ELSET=nameThe *EMBEDDED ELEMENT option must be included in themodel definition portion of the input file. Multiple *EMBEDDEDELEMENT options are allowed.ABAQUS/CAE Usage: Interaction module: Create Constraint: Embedded region:choose Select Region from the prompt area whenselecting the host regionSpecifying the embedded elementsYou must specify the embedded elements. Individual elements or element sets can be specified.An embedded element may share some nodes with host elements. These nodes, however, will not be considered to be embedded nodes.Input File Usage: *EMBEDDED ELEMENTembedded elementsABAQUS/CAE Usage: Interaction module: Create Constraint: Embedded region:select the embedded regionDefining geometric tolerancesA geometric tolerance is used to define how far an embedded node can lie outside the regions of the host elements in the model. By default, embedded nodes must lie within a distance calculated by multiplying the average size of all non-embedded elements in the model by 0.05; however, you can change this tolerance.You can define the geometric tolerance as a fraction of the average size of all non-embedded elements in the model. Alternatively, you can define the geometric tolerance as an absolute distance in the length units chosen for the model. If you specify both exterior tolerances, ABAQUS uses the tighter tolerance of the two. The exterior tolerance for embedded elements in host elements is indicated by the shaded region in Figure 20.4.1–1.The exterior tolerance for embedded elements.Figure 20.4.1–1If an embedded node is located inside the specified tolerance zone, the node is constrained to the host elements. The position of this node will be adjusted to move the node precisely onto the host elements. If an embedded node is located outside the specified tolerance zone, an error message will be issued.Input File Usage: Use the following option to define the tolerance as a fraction:*EMBEDDED ELEMENT, EXTERIOR TOLERANCE=toleranceUse the following option to define the tolerance as anabsolute distance:*EMBEDDED ELEMENT,ABSOLUTE EXTERIOR TOLERANCE=toleranceABAQUS/CAE Usage: Interaction module: Create Constraint: Embedded region:Fractional exterior tolerance or Absolute exteriortoleranceAdjusting the positions of embedded nodesIf an embedded node lies close to an element edge or an element face within a host element, it is computationally efficient to make a small adjustment to the position of the embedded node so that the node will lie precisely on the edge or face of the host element. A small tolerance, below which the weight factors of the nodes on a host element associated with an embedded node will be zeroed out, is defined. The small weight factors will be redistributed to the other nodes on the host element in proportion to their initial weights, and the position of the embedded node will be adjusted based on the new weight factors. This adjustment is performed only at the start of the analysis and does not create any strain in the model. It is most useful for making small adjustments to make the embedded nodes lie on the edge or face of a host element. If a large nondefault value of the roundoff tolerance is used to make significant adjustments to the positions of the embedded nodes, you should carefully review the mesh obtained after adjusting.Input File Usage: *EMBEDDED ELEMENT, ROUNDOFF TOLERANCE=toleranceABAQUS/CAE Usage: Interaction module: Create Constraint: Embedded region:Weight factor roundoff toleranceUse with other multiple kinematic constraints inABAQUS/StandardIn ABAQUS/Standard if an embedded node is also tied by multi-point, equation, kinematic coupling, surface-based tie, or rigid body constraints, an overconstraint is introduced and an error message will be issued. If a boundary condition is applied to an embedded node, the embedded element definition always takes precedence. The boundary condition will be neglected, and a warning message will be issued.LimitationsThe following limitations exist for the embedded element technique: •Elements with rotational degrees of freedom cannot be used as host elements.•Rotational, temperature, pore pressure, acoustic pressure, and electrical potential degrees of freedom at an embedded node are notconstrained.•Host elements cannot be embedded themselves.•The material defined for the host element is not replaced by the material defined for the embedded element at the same location of the integration point.•Additional mass and stiffness due to the embedded elements are added to the model.ExampleConsider the example in Figure 20.4.1–2.Figure 20.4.1–2 Elements lie embedded in host elements.Elements 3 (truss) and 4 (membrane) lie embedded in elements 1 and 2. Element 1 is formed by nodes a, b, c, d, e, f, g, and h; element 2 is formed by nodes e, f, g, h, i, j, k, and l; element 3 is formed by nodes A and B; and element 4 is formed by nodes C, D, E, and F. If the host element set includes elements 1 and 2 and the embedded element sets contain elements 3 and 4, respectively, ABAQUS will attempt to find if there are any embedded nodes (A, B, C, D, E, and F) lying within host elements 1 or 2. If node A is found to be lying close to the a-b-f-e face of element 1, all the degrees of freedom at node A are constrained to nodes a, b, f, and e, with appropriate weight factors being determined based on the geometriclocation of node A in element 1. Similarly, if node B is found to be lying inside element 1 and node E is found to be lying close to the g–k edge of element 2, respectively, all the degrees of freedom at node B are constrained to nodes a, b, c, d, e, f, g, and h, and all the degrees of freedom at node E are constrained to nodes g and k, with appropriate weight factors being determined based on the geometric location of node B in element 1 and the geometric location of node E on the g–k edge of element 2, respectively.You should make sure that all the nodes on the embedded elements are properly constrained to nodes on the host elements. This can be verified by performing a data check analysis (see “Execution procedure forABAQUS/Standard and ABAQUS/Explicit,” Section 3.2.2). For each embedded node a list of nodes that are used to constrain this node and the associated weight factors are output to the data file during the data check analysis. An error message is issued if an embedded node is not constrained.Template*HEADING…*NODEData line to define the nodal coordinates*ELEMENT, TYPE=C3D8, ELSET=SOLID3DData line to define the solid elements*ELEMENT, TYPE=T3D2, ELSET=TRUSSData line to define the truss elements*ELEMENT, TYPE=M3D4, ELSET=MEMBData line to define the membrane elements*EMBEDDED ELEMENT, EXTERIOR TOLERANCE=tolerance, HOST ELSET=SOLID3D TRUSS, MEMB*STEP*STATIC(or any other allowable procedure)Data line to define step time and control incrementation…*END STEPABAQUS Analysis User's Manual。
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• 2004年，软件统计数据为：
• 套装软件共计478亿元，为具有独立产品形态的软件。
– 其中包括系统软件89亿元（操作系统44.19亿元、数据库管理系统 20.06亿元、支撑软件25.71亿元）、
– 中间件软件6.98亿元、 – 应用软件304.53亿元（包括通用应用软件（安全软件、办公软
医疗市场
• 心脏除颤器 • 心脏起搏器 • 患者信息和监视系统 • 理疗控制系统 • 电磁成像系统等
军事领域
军事工业应用特点 • 市场垄断性强 • 高利润 • 可靠性要求高 • 安全性要求高 • 成本要求不高
军事工业产品
• 数字化单兵信息装备 • 夜视扫描、全球定位、指挥通信
21世纪部队旅及旅以下作战指挥系统 （FBCB2） C4ISR系统(指挥、控制、通讯、电脑、情报、监视、侦察)
• ARM嵌入式处理器结构与应用基础，马忠 梅等，北航出版社，2002
• 嵌入式系统开发圣经，探矽工作室，中国 青年出版社，2002
参考文献(2)
• 嵌入式Linux系统设计与应用.王学龙. 清 华大学出版社，2001年
• UC/OS-II－源代码公开的实时嵌入式操 作系统.邵贝贝. 中国电力出版社，2001
– 嵌入式系统工业的基础是以应用为中心的“芯 片”设计和面向应用的软件产品开发。
嵌入式系统具有的产品特征
• 面向用户、面向产品、面向应用 • 升级换代也是和具体产品同步 ,具有较长的
生命周期
– 软件和硬件结合紧密
• 嵌入式处理器的发展也体现出稳定性
– 普通处理器18月 – 嵌入式处理器8~10年
嵌入式系统软件的特征
• 4.温度和湿度:
– 大多数军事和空间系统是工作在温度和湿度环境相对不可控的条件下。 用于军事和空间产品的电子产品的可靠工作范围必须在-40℃~+85℃。
嵌入式系统热点应用
• 信息家电 • 车载系统 • 军事工业 • 医疗器械
信息家电应用特点
• 市场巨大 • 低成本要求 • 利润空间小 • 竞争激烈 • 人机界面友好 • 网络化
– 电池寿命自然是设计运动或可携带军事系统和空间设备的关键问题。因 为发热与功耗成正比，降低功耗就成了对工作在较高温度环境中的系统 的重要要求。
• 3.震动和冲击:
– 军事和空间系统要适合在恶劣运动环境中工作和贮存。这些环境包括： 大范围或小范围的重复运动；芯片、模块和模板可能部分或全部变位或 断线；由于震动而加重的电化学反应引起的腐蚀，使模板互连金手指管 脚的导电性能变差；由于使用硬盘驱动器致使数据的完整性成为难题 等。
件、管理软件、游戏软件、教育软件等）与行业应用软件（金 融、电信、政府等））、
• 嵌入式软件（673.62亿元）
• 另外软件服务（937.48亿元）：除生产产品化软件之外的 所有的软件研发及相关活动，包括系统集成、软件外包、 咨询、数据加工和处理等
Q101 Q201 Q301 Q401 Q102 Q202 Q302 Q402 Q103 Q203 Q303 Q403 Q104 Q204 Q304 Q404 Q105 Q205 Q305 Q405 Q106
• 可编程逻辑器件及设计 Xilinx, altera等 的官方网站
嵌入式教学国内背景
单一课程：2002年开始，研究生课程:《嵌入式系统设计》、 《嵌入式操作系统》等 2004年开始，本科生选修课《嵌入式系统概论》 2005年个别院校转为相关专业的专业基础课
独立专业：2003年，北大软件学院成立“嵌入式系统”专业 2005年北航软件学院成立嵌入式软件专业， 部分高职院校设立嵌入式专业；
ROM/EPROM、RAM、总线、总线逻辑、定时/ 计数器、WatchDog、I/O、串行口、脉宽调制输 出、A/D、D/A、Flash RAM、EEPROM等各种必 要功能和外设 • 微控制器的最大特点是单片化，体积大大减小， 从而使功耗和成本下降、可靠性提高。
嵌入式微控制器(MCU)
• 代表性的通用系列包括8051、P51XA、 MCS-251、MCS-96/196、C166/167、 MC68HC05/11/12/16、68300等。
运输市场
• 航空、铁路、公路运输系统 • 航空管理、雷达系统 • 交通指挥系统 • 停车系统、售票系统 • 乘客信息系统 • 检票系统 • 行李处理系统 • 应急设备等
建筑市场
• 电力供应，备用电源和发电机，火警控制 系统，供热和通风系统，电梯和升降系 统，车库管理，安保系统，电子门锁系 统，楼宇管理系统，闭路电视系统，电子 保险柜，警铃等
• 软件要求固态化存储 • 软件代码高质量、高可靠性 • 系统软件(OS)的高实时性是基本要求 • 多任务操作系统是知识集成的平台和走向
工业标准化道路的基础
• 据CCID2003年的数据显示，2000年嵌入式 软件市场规模为70.33亿元，2001年为 95.43亿元，2002年118.56亿元，三年平均 增长38.85%。
• 目前IP电话发展现状
– 据ＩＤＣ统计，全球ＩＰ电话业务收入综合年增长率 将以１０８％的速度增长，到２００３年ＩＰ电话已 占国际电话业务量的三分之一。到２００４年，国际 长途将占ＩＰ业务市场的７５％。ＩＰ电话已成为当 前各国电话运营重点发展的业务之一。
PDA的应用领域及市场潜力
通讯产品
工业市场
• 嵌入式系统则是要和构各件个不化同行业的应用
相结合的，其开发人员往往是各个应用领 域的专家。
因此开发工具的易学、易用、可靠、高效 是基本要求。
嵌入式系统的组成
2 嵌入式系统的应用
嵌入式系统无处不在
家用市场
• 机顶盒、掌上电脑、DVD、MP3、数码 相机、数字电视、WebTV、网络冰 箱、网络空调、家庭网关、智能家用 电器、嵌入式视频服务器、车载导航 器系统等
• 能执行特定功能的计算机硬件和软件的结合体 • 微软在2002年将嵌入式系统定义为完成某一特定
功能、或是使用某一特定嵌入式应用软件的计算 机或计算装置。 • 广义定义:任何一个非计算机的计算系统
• 传统嵌入式系统 :应用于军事、工业控制和 仪器仪表等
• 新型嵌入式系统 : 3C ( Computer, Consumer & Communication ) 和信息家电 IA ( Information Appliance )
嵌入式系统简介
Dr. Wang Hongpeng TA: Zhou JunFei Office：C305C Telephone：26033618 Email：wanghp@
参考资料
• 嵌入式计算机系统设计原理，computers as components, principles of embedded computing system design, wayne wolf, 机械工业出版社，2002
– 只保留和嵌入式应用有关的母板功能
• 增强工作温度、抗电磁干扰、可靠性等方面 • 功能与和工业控制计算机相似 • 嵌入式处理器目前主要有Am186/88、386EX、
SC-400、Power PC、68000、MIPS、ARM系列 等
嵌入式微控制器(MCU)
• 又称单片机 • 以某一种微处理器内核为核心，芯片内部集成
嵌入式系统软件需要RTOS开发平台
• 通用计算机具有完善的操作系统和应用程 序接口(API)，但一 般不是实时的。
• 嵌入式系统则不同，应用程序可以没有操 作系统直接在芯片上运行。
• 但为了保证程序执行的实时性、可靠性， 并减少开发时间，保障软件质量。需要选 配RTOS开发平台
以应用为主
• 通用计算机的开发人员一般是计算机科学 或计算机工程方面的专业人士。
嵌入式视频服务器的架构
数码多媒体产品
现代化家庭
信息家电
中国数字电视发展规划
• 2002年完成地面广播传输标准的测试； • 2002年底颁布国家数字电视有线传输标准； • 2003年底前颁布国家数字电视地面广播标准和相
关配套标准，确定数字电视标准体系； • 2005年在有条件的城市推广数字电视播出； • 2008年的北京奥运会上向全世界传输数字高清晰
专业方向：2004年，部分院校本科专业设立嵌入式专业方向
计算机系统的三大领域
• 服务器
– 利润最大的市场 – 可用性 – 可扩展性 – 有效带宽
• 桌面
– 最广阔的市场
• 嵌入式
– 潜力最大的市场
1 嵌入式系统定义
• 嵌入式系统是嵌入至对象体内的专用计算机系统 (IEEE)
• 任何包含一个或多个专用的计算机、微处理器或 微控制器的电子设备
度电视节目，主要的大城市开始数字电视商业广 播； • 2015年数字电视成为我国电视播出的主要方式。
信息家电
通信市场
• 电话交换系统 • 电缆系统 • 卫星和全球定位系统 • 数据交换设备 • 移动电话 • PDA • 等等
• 智能网络电话机
– 通过普通电话线与网络相连。
• 宽带网络电话机
– 通过宽带接入Internet。
• 美国科学家预言：嵌入式是继PC和网络之后 的最伟大发明，未来将会成为主流技术。
嵌入式产品种类多样
> 90%
CPU
< 10%
21世纪嵌入 式系统应用 无处不在
带带44个个轮轮子子 的的计计算算机机
嵌入式系统的应用
嵌入式系统的特点和要求
• 嵌入式系统是不可垄断的高度分散的行业
– PC由WINTEL垄断
• 制造工厂污水处理系统 • 发电站和电力传输系统 • 自动化工厂控制系统开发，维护和测试的
工具 • 石油提炼和相关的贮运设施，建筑设备 • 计算机辅助制造系统 • 能源控制系统，核电站 • 机器人系统等