论文电子信息类外文翻译
电子信息工程外文翻译 外文文献 英文文献
电子信息工程电路编程中的AT89C51单片机译文标题电路编程中的AT89C51单片机AT89C51 In-Circuit Programming 原文标题作者Robert W.Sparks等译名国籍美国斯帕克等W.罗伯特Atmel Corporation原文出处摘要本应用说明的是ATMEL公司AT89C51的电路可编程闪存的微控制器。
为在电路可编程AT89C51的应用提出了与应用程序相关的例子，它的修改要求支持在线编程。
这种方法显示在该应用程序中的AT89C51单片机可通过商业电话线远程改编。
本应用笔记中描述的电路，仅支持5伏电压下编程，需要使用一个AT89C51-XX-5。
标准A T89C51的需要12伏电压。
该应用程序的软件可从ATMEL下载。
总论当不在进行程序设计的时候，在电路设计中的AT89C51设计将变得透明化。
在编程期间必须重视EA/VPP这一脚。
在不使用外部程序存储器的应用程序中，这脚可能会永久接到VCC。
应用程序使用的外部程序存储器要求这一脚为低电平才能正常运行。
RST在编程期间必须为高电平。
应该提供一种方法使得电路通入电源以后，使RST代替主要的复位电路起到复位的作用。
在编程过程中，PSEN必须保持低电平，在正常运行期间绝不能使用。
ALE/ PRO在编程过程中输出低电平，在正常运行期间绝不能使用在编程过程中AT89C5I / 端口是用于模式应用程序，地址和数据选择的，可能要该控制器从应用的电路隔离。
如何做到这一点取决于应用程序输入端在编程过程中，控制器必须与应用电路的信号来源隔离。
带有三个输出状态的缓冲区在应用程序之间插入电路和控制器，同时在编程时缓冲区输出三种状态。
一个多路复用器用于信号源之间进行选择，适用于任何一方的应用电路或编程控制器电路的信号输出端如果应用的电路可以允许端口在编程过程中的状态变化，则不需要改变电路。
如果应电路的状态，必须事先在编程过程中的保持不变，可能在控制器和应用电路中插入锁存。
电子信息工程专业毕业论文外文翻译
本科毕业设计（论文) 中英文对照翻译院(系部）电气工程与自动化专业名称电子信息工程年级班级 04级7班学生姓名指导老师Infrared Remote Control SystemAbstractRed outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique，drive numerous hardware and software platform support. Red outside the transceiver product have cost low, small scaled turn，the baud rate be quick，point to point SSL，be free from electromagnetism thousand Raos etc.characteristics，can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission，at short distance wireless deliver aspect to own very obvious of advantage。
Along with red outside the data deliver a technique more and more mature，the cost descend，red outside the transceiver necessarily will get at the short distance communication realm more extensive of application。
电子信息工程专业外文翻译--滤波器
外文原文一、a question for study or discussion1．Research background and purpose1.1 conceptualizeElliptic filter (Elliptic filter), also known as the Call filter (Cauer filter), is in the passband and stopband ripple of a filter. Elliptic filter when compared to other types of filters, in order under the same conditions with minimal fluctuations in the passband and stopband. Same as its wave in passband and stopband, which distinguish it from the Butterworth filter with flat passband and stopband and flat passband and the stopband ripple or resistance with flat, cut than the snow filter passband ripple.A low-pass filter with a frequency response range of the ellipse：Four-order low-pass elliptic filter frequency response。
1.2 scientific researchIn the low-frequency (600Hz=500KHz) commonly used in band-pass filter, large LC filters, poor stability, stability of Crystal filters, but can only be made of narrow-band filter, bad shock and vibration resistance. Active filters are small, but stability and decay characteristics are often poor, and debugging easy. Ceramic filter is poor and low-frequency seismic performance of low temperature coefficient. And than snow filter Butterworth filter transfer function is a polynomial divided by a constant, for the whole network, all zeros in infinite, only infinite stopband attenuation is infinite, and the elliptic filter in both with zeros and poles on the limited frequency. Zero ripple in the passband, that it has a minimum across the passband and stopband ripple, This is distinguished from Butterworth filter with flat passband and stopband。
外文翻译排版格式参考
毕业设计(论文)外文资料翻译系别：电子信息系专业：通信工程班级：B100309姓名：张杨学号：B10030942外文出处：附件： 1. 原文； 2. 译文2014年03月An Introduction to the ARM 7 ArchitectureTrevor Martin CEng, MIEETechnical DirectorThis article gives an overview of the ARM 7 architecture and a description of its major features for a developer new to the device. Future articles will examine other aspects of the ARM architecture.Basic CharacteristicsThe principle feature of the ARM 7 microcontroller is that it is a register based load-and-store architecture with a number of operating modes. While the ARM7 is a 32 bit microcontroller, it is also capable of running a 16-bit instruction set, known as "THUMB". This helps it achieve a greater code density and enhanced power saving. While all of the register-to-register data processing instructions are single-cycle, other instructions such as data transfer instructions, are multi-cycle. To increase the performance of these instructions, the ARM 7 has a three-stage pipeline. Due to the inherent simplicity of the design and low gate count, ARM 7 is the industry leader in low-power processing on a watts per MIP basis. Finally, to assist the developer, the ARM core has a built-in JTAG debug port and on-chip "embedded ICE" that allows programs to be downloaded and fully debugged in-system.In order to keep the ARM 7 both simple and cost-effective, the code and data regions are accessed via a single data bus. Thus while the ARM 7 is capable of single-cycle execution of all data processing instructions, data transfer instructions may take several cycles since they will require at least two accesses onto the bus (one for the instruction one for the data). In order to improve performance, a three stage pipeline is used that allows multiple instructions to be processed simultaneously.The pipeline has three stages; FETCH, DECODE and EXECUTE. The hardware of each stage is designed to be independent so up to three instructions can be processed simultaneously. The pipeline is most effective in speeding up sequential code. However a branch instruction will cause the pipeline to be flushed marring its performance. As we shall see later the ARM 7 designers had some clever ideas to solve this problem.InstructionFig 1 ARM 3- Stage pipelineARM7 Programming ModelThe programmer's model of the ARM 7 consists of 15 user registers, as shown in Fig. 3, with R15 being used as the Program Counter (PC). Since the ARM 7 is a load-and- store architecture, an user program must load data from memory into the CPU registers, process this data and then store the result back into memory. Unlike other processors no memory to memory instructions are available.M1M2M34,R1,R2 (R4=R0+R2)3Fig 2 Load And Store ArchitectureAs stated above R15 is the Program Counter. R13 and R14 also have special functions; R13 is used as the stack pointer, though this has only been defined as a programming convention. Unusually the ARM instruction set does not have PUSH and POP instructions so stack handling is done via a set of instructions that allow loading and storing of multiple registers in a single operation. Thus it is possible to PUSH or POP the entire register set onto the stack in a single instruction. R14 has special significance and is called the "link register". When a call is made to a procedure, the return address is automatically placed into R14, rather than onto a stack, as might be expected. A return can then be implemented by moving the contents of R14 intoR15, the PC. For multiple calling trees, the contents of R14 (the link register) must be placed onto the stack.15 User registers +PCR13 is used as the stack pointer R14 is the link registerR14 is the Program Counter Current Program Status RegisterFig 3 User Mode Register ModelIn addition to the 16 CPU registers, there is a current program status register (CPSR). This contains a set of condition code flags in the upper four bits that record the result of a previous instruction, as shown in Fig 4. In addition to the condition code flags, the CPSR contains a number of user-configurable bits that can be used to change the processor mode, enter Thumb processing and enable/disable interrupts.31 30 29 28 27Negative Carry OverflowIRQ System UserUndefined instruction AbortThumb instruction setFig 4 Current Program Status Register and Flags Exception And Interrupt ModesThe ARM 7 architecture has a total of six different operating modes, as shown below. These modes are protected or exception modes which have associated interruptsources and their own register sets.User: This mode is used to run the application code. Once in user mode the CPSR cannot be written to and modes can only be changed when an exception is generated. FIQ: (Fast Interrupt reQuest) This supports high speed interrupt handling. Generally it is used for a single critical interrupt source in a systemIRQ: (Interrupt ReQuest) This supports all other interrupt sources in a system Supervisor: A "protected" mode for running system level code to access hardware or run OS calls. The ARM 7 enters this mode after resetAbort: If an instruction or data is fetched from an invalid memory region, an abort exception will be generatedUndefined Instruction:If a FETCHED opcode is not an ARM instruction, an undefined instruction exception will be generated.The User registers R0-R7 are common to all operating modes. However FIQ mode has its own R8 -R14 that replace the user registers when FIQ is entered. Similarly, each of the other modes have their own R13 and R14 so that each operating mode has its own unique Stack pointer and Link register. The CPSR is also common to all modes. However in each of the exception modes, an additional register一the saved program status register (SPSR)，is added. When the processor changes the current value of the CPSR stored in the SPSR，this can be restored on exiting the exception mode.System&User FIQ Supervisor Abort IRQ Undefined Fig 5 Full Register Set For ARM 7Entry to the Exception modes is through the interrupt vector table. Exceptions in the ARM processor can be split into three distinct types.(i) Exceptions caused by executing an instruction, these include software interrupts, undefined instruction exceptions and memory abort exceptions(ii) Exceptions caused as a side effect of an instruction such as a abort caused by trying to fetch data from an invalid memory region.(iii) Exceptions unrelated to instruction execution, this includes reset, FIQ and IRQ interrupts.In each case entry into the exception mode uses the same mechanism. On generation of the exception, the processor switches to the privileged mode, the current value of the PC+4 is saved into the Link register (R14) of the privileged mode and the current value of CPSR is saved into the privileged mode's SPSR. The IRQ interrupts are also disabled and if the FIQ mode is entered, the FIQ interrupts are also disabled, Finally the Program Counter is forced to the exception vector address and processing of the exception can start. Usually the first action of the exception routine will be to pushPrefetch Abort(instruction fetch memory abort)Software interrupt (SWI)Undefined instruction ResetData Abort (data access momory abort)IRQ (interrupt)FIQ (fast interrupt)Supervisor Undefined Supervisor Abort Abort IRQ FIQ0x000000000x0000001C0x000000040x0000000C 0x000000080x000000100x00000018Fig 6 ARM 7 Vector TableA couple of things are worth noting on the vector table. Firstly, there is a missing vector at 0x000000014. This was used on an earlier ARM architecture and is left empty on ARM 7 to allow backward compatibility. Secondly, the FIQ interrupt is at the highest address so the FIQ routines could start from this address, removing the need for a jump instruction to reach the routine. It helps make entry into the FIQ routine as fast as possible.Once processing of the exception has finished, the processor can leave the privileged mode and return to the user mode. Firstly the contents of any registers previously saved onto the stack must be restored. Next the CSPR must be restored from the SPSR and finally the Program Counter is restored by moving the contents of the link register to R15, (i.e. the Program Counter). The interrupted program flow can then restart.Data TypesThe ARM instruction set supports six data types namely 8 bit signed and unsigned, 16 bit signed and unsigned plus 32 bit signed and unsigned. The ARM processor instruction set has been designed to support these data types in Little or Big-endian formats. However most ARM silicon implementations use the Little-endian format. ARM instructions typically have a three-operand format, as shown belowADD Rl，R2, R3 ; Rl=R2+R3ARM7 Program Flow ControlIn all processors there is a small group of instructions that are conditionally executed depending on a group of processor flags. These are branch instructions such as branch not equal. Within the ARM instruction set, all instructions are conditionally executable.31 28CONDFig. 7 Instruction Condition Code BitsThe top four bits of each instruction contain a condition code that must be satisfied if the instruction is to be executed. This goes a long way to eliminating small branches in the program code and eliminating stalls in the pipeline so increasing the overall program performance. Thus for small conditional branches of three instructions or less, conditional execution of instructions should be used. For larger jumps, normal branching instructions should be used.Fig. 8 Instruction Condition CodesThus our ADD instruction below could be prefixed with a condition code, as shown. This adds no overhead to instruction executionEQADD R1，R2，R3 ;If(Zero flag = 1)then R1 = R2+R3The ARM7 processor also has a 32-bit barrel shifter that allows it to shift or rotate one of the operands in a data processing instruction. This takes place in the same cycle as the instruction. The ADD instruction could be expanded as followsEQADD R1，R2 R3，LSL #2 ; If ( Zero flag = 1) then R1 = R2+ (R3 x 4) Finally the programmer may decide if a particular instruction can set the condition code flags in the CPSR.EQADDS R1，R2 R3，LSL #2; If (Zero flag = 1) then R1 = R2 + (R3 x4)and set condition code flagsIn the ARM instruction set there are no dedicated call or return instructions. Instead these functions are created out of a small group of branching instructions.The standard branch (B) instruction allows a jump of around+-32Mb. A conditional branch can be formed by use of the condition codes. For example, a "branch notequal" would be the branching instruction B and the condition code "NE" for not equal giving "BNE". The next form of the branch instruction is the branch with link. This is the branch instruction but the current value of the PC +4 is saved into R14, the link register. This acts as a CALL instruction by saving the return address into R14. A return instruction is not necessary since a return can be implemented by moving R14 into the PC. The return is more complicated in the case of an interrupt routine. Depending on the type of exception, it may be necessary to modify the contents of the link register to get the correct return address. For example, in the case of an IRQ or FIQ interrupt, the processor will finish its current instruction, increment the PC to the next instruction and then jumping to the vector table. This means that the value in the link register is PC+4 or one instruction ahead of the return address. This means we need to subtract 4 from the value in the link register to get the correct return address. This can be done in a single instruction thus: SUBS pc, r14, #4// PC=Link register-40x80000x400PC=0x80000x4000x8000Fig 9 Branch and Branch Link Instruction OperationBranching instructions are also used to enter the 16-bit Thumb instruction set. Both the branch and branch-with-link may perform an exchange between 32-bit and 16-bit instruction sets and vice versa .The Branch exchange will jump to a location and start to execute 16-bit Thumb instructions. Branch link exchange will jump to a location, save PC+4 into the link register and start execution of 16-bit Thumb instructions. In both cases, the T bit is set in the CPSR. An equivalent instruction is implemented in the Thumb instruction set to return to 32-bit ARM instruction processing.0x8000T=1Y=10x4000x4000x8000Fig. 10 Branch Exchange and Branch Link Exchange Instruction Operation Software InterruptsThe ARM instruction set has a software interrupt instruction. Execution of thisinstruction forces an exception as described above; the processor will enter supervisor mode and jump to the SWI vector at 0x00000008.Fig. 11 Software Interrupt InstructionThe bit field 0-23 of the SWI instruction is empty and can be used to hold an ordinal. On execution of an SWI instruction, this ordinal can be examined to determine which SWI procedure to run and gives over 16 million possible SWI functions.…Swi_ #1 . call swi function one…Tn the swi handlerregister unsigned*link ptr asm ("r14")；// define a pointer to the hnk register Switch ((*(link-ptr-1))&Ox00FFFFFF) //calculate the number of the swi function{Case 0x01 : SWI_unction (); //Call the function…}This can be used to provide a hardware abstraction layer. In order to access OS calls or SFR registers, the user code must make a SWI call . All these functions are therunning in a supervisor mode, with a separate stack and link register.As well as instructions to transfer data to and from memory and to CPU registers, the ARM 7 has instructions to save and load multiple registers. It is possible to load or save all 16 CPU registers or a selection of registers in a single instruction. Needless tosay, this is extremely useful when entering or exiting a procedure.M0Fig. 12 Load and Store Multiple Instruction OperationThe CPSR and SPSR are only accessed by two special instructions to move their contents to and from a CPU register. No other instruction can act on them directly.MSRMRSR15R15Fig. 13 Programming The SPSR And CPSR RegistersTHUMB SupportThe ARM processor is capable of executing both 32-bit (ARM) instructions and 16- Bit (Thumb instructions). The Thumb instruction set must always be entered byrunning a Branch exchange or branch link exchange instruction and NOT by setting the T bit in the CPSR. Thumb instructions are essentially a mapping of their 32 bit cousins but unlike the ARM instructions, they are unconditionally executed except though for branch instructions.Fig. 14 Thumb Instruction ProcessingThumb instructions reduced number of only have unlimited access to registers RO-R7 and R13一Rl5. A instructions can access the full register set.Fig.15 Thumb programmers modelThe Thumb instruction set has the same load and store multiple instructions as ARM and in addition, has a modified version of these instructions in the form of PUSH and POP that implement a full descending stack in the conventional manner. The Thumb instruction set also supports the SWI instruction, except that the ordinal field is only 8 bits long to support 256 different SWI calls. When the processor is executing Thumb code and an exception occurs, it will switch to ARM mode in order to process the exception. When the CPSR is restored the, Thumb bit will be reset and the processor continues to run Thumb instructions.BCXBXFig.16 Thumb Exception ProcessingThumb has a much higher code density than ARM code, needing some 70% of the space of the latter. However in a 32-bit memory, ARM code is some 40% faster than Thumb. However it should be noted that if you only have 16-bit wide memory then Thumb code will be faster than ARM code by about 45%. Finally the other important aspect of Thumb is that it can use up to 30% less power than ARM code.ARM7的体系结构介绍特里沃马丁曾，鼠技术总监本文给出了ARM 7架构的概述和开发新的设备，以及主要功能的描述，未来将研究ARM体系结构的其他方面。
电子信息专业外文翻译---EDA的发展及VHDL的应用
EDA的发展及VHDL的应用90's in 20 centuries, international last electronics and calculator technique more the forerunner's nation, has been being actively investigating a new design method of the electronics electric circuit, and carried on an exhaustive change in the aspects of designing a method, tool wait, obtain huge success.At the design realm of the electronics technique, the application of programmable logic spare part(like CPLD, FPGA), have already got extensive universality, these spare parts brought tremendous vivid for the design of numerical system.These spare parts can pass a software plait a distance but as to it's hardware structure and work the way carry on heavy Gou and make thus the design of hardware can like software design so convenient fast.The all these biggest changed a traditional numerical method, design process of the system design and design idea and promoted the EDA technical quick development.The EDA is an electronics design automation(the Automation of the Electronic Design) of abbreviation, design(CAD) from the calculator assistance at the beginning of 90's in 20 centuries, calculator assistance manufacturing(CAM), calculator assistance test(CAT) and calculator lend support to the concept of engineering(CAE) a development since then.The EDA technique is to take calculator as tool, design at EDA software terrace up, use the hardware description language HDL completion a design a document, then is of oneself completed logic to edit and translate, turn Chien, partitioned by the calculator, comprehensive, excellent turn, set up, cloth line with imitate really, until for particular target chip of proper go together with to edit and translate, the logic reflect to shoot with plait distance download etc. work.The EDA technical emergence, biggest raised efficiency and maneuverability of electric circuit design, eased to design of labor strength.These spare parts can pass a software plait a distance but as to it's hardware structure and work the way carry on heavy Gou and make thus the design of hardware can like software design so convenient fast.The all these biggest changed a traditional numerical method, design process of the system design and design idea and promoted the EDA technical quick development.Make use of EDA tool, the electronics designer can start design electronics system from the concept, calculate way, agreement...etc., a great deal of work can pass calculator completion, and can design the electronics product is from the electric circuit, the function analyze compute of the whole process of design an IC landscape or PCB landscape on board auto processing completion.Use to the EDA concept or category very breadth now.Include in each realm of the machine, electronics, correspondence, aviation aerospace, chemical engineering, mineral, living creature, medical science, military...etc., all there is EDA application.The EDA technique has already extensively used in each archduke department, the Qi business unit and research teaching section currently.For example in the airplane the manufacturing the process, from design, performance test and characteristic analytical until fly emulation, may involve an EDA technique.The EDA technique that this text point mainly to the design, PCB design of the electronics electric circuit and IC design. The EDA design can is divided into system class, electric circuit class and physics to carry out class. The EDA in common use software:The EDA tool pile up one after another and get into an our country currently and have the EDA software of extensive influence to have:MultiSIM 7(the latest edition of original EWB), PSPICE, OrCAD, PCAD, Protel, Viewlogic, Mentor, Graphics, Synopsys, LSIIogic, Cadence, MicroSim, ISE, modelsim etc..These tools all have stronger function, generally can used for a few aspects, for example a lot of softwares all can carry on an electric circuit design with imitate really, together entering can also carry on PCB to automatically set up cloth line, can output various net form a document with the third square software connect.The VHDL English full name be the HardwareDescription Language of the Integrated Circuit of the Very-High-Speed, birth in 1982.At the end of 1987, the VHDL is confirm by IEEE and American Ministry ofNational Defense to describe language for the standard hardware.Announced VHDL standard edition from the IEEE, IEEE-1076(call 87 versions) after, the each EDA company released own VHDL design environment one after another, or declared that the own design tool can connect with VHDL.Henceforth the VHDL designed realm to get to extensively accept in the electronics, and gradually replaced an originally not- standard hardware description language.In 1993, the IEEE carried on to revise to the VHDL, describe ability to up expand a VHDL contents from higher abstract layer and the system, announced the VHDL of new edition, namely IEEE standard of 1076-1993 editions, .(call 93 versions)Now, VHDL and Verilog are the industrial standard hardware description of the IEEEs language, again arrive support of numerous EDA companies, at electronics engineering realm, have become in general use hardware to describe language in fact.There is expert think, in the new century in, the VHDL will start to undertake a greatly part of numerical system design mission at the Verilog language. The VHDL language is a kind of deluxe language which useds for an electric circuit design.It expects to appear after the 80's of.BE at the beginning come out by American Ministry of National Defense development to provide the American solider with the credibility which uses to raise a design with cut 1 kind of development period to use the scope smaller design language.All of VHDL Englishes write BE:The Descriptiong Language of the VHSIC(the Speed Integrated of the Very High Circuit) Hardware.Translating into Chinese is soon extremely high the description language of the integrated circuit hardware.So it of the application mainly is an application in the design of numerical electric circuit.Currently, it is in the application most in China is the design which uses in the FPGA/CPLD/EPLD.Certainly in some units with stronger real strenght, it is also use to design ASIC.The VHDL mainly useds for the structure, behavior which describes numerical system, function with connect.In addition to implying many languages sentence which have a hardware characteristic, VHDL languages forms and description style and sentence construction are very similar at general calculator deluxe language.VHDL procedure structure characteristics is an engineering design, or call that the design entity(can be a component, an electric circuit mold piece or a system) is divided into exterior(or call but part, and port) with inner part(or call to can't see part), since involve internal function and calculate way of entity to complete part of.At to 1 designed entity to define exterior interface after, once it internal development completion after, other designs can directly adjust to use this entity.This kind of will design entity to be divided into a little bit basic VHDL system that is a VHDL system inside the concept of outside part design design of a little bit basic and other hardware describe the language compare and the VHDL has a following characteristics: The function is strong and the design be vivid.The VHDL has the function strong language structure, can describe a complicated logic control with the simple and direct and explicit source code.It has a multi-layer design description function, in multiple layers thin turn, finally directly born electric circuit class description.The VHDL supports synchronous electric circuit, difference's tread electric circuit with random the design of electric circuit, this be the other hardware description although the language can't compare to.The VHDL still supports various design method, since support from the bottom upward design, support again from the design of crest declivity;Since the support mold piece turns a design, support layer's turn a design again. Support extensively and be easy to a modification.Because the VHDL has already become IEEE standard the norm of hardware description language, most EDA tools almost support VHDL currently, this is VHDL of further expansion with extensively applied lay foundation.In the design process of the hardware electric circuit, the main design document is the source code which writes with the VHDL, the VHDL easily reads with the structure turn, so be easy to a modification design.The strong system hardware describes ability.The VHDL has a multi-layer design description function, since can describe system class electric circuit, can describe door class electric circuit again.And description since can adopt a behavior description, deposit a machine to deliver description or structure description, can also adopt thehybrid description of threes mixture.Moreover, VHDL support is inertial to delay and deliver to delay, can also accurately build up hardware electric circuit model.VHDL support prepare definite of with from definition of data type, bring hardware description a bigger freedom degree, make design the personnel can expediently establish the system model of high time. The independence is at the design of spare part, have nothing to do with the craft.Don't need to consider a choice completion the spare part of design first while designing a personnel to carry on a design with the VHDL, can concentrate energy to carry on design of excellent turn.When the design description complete after, can carry out its function with various different spare part structure. Very strong transplantation ability.The VHDL is a kind of hardware description for standardize language, the same of design description can be support by the different tool and make to design to describe of the transplantation make possible.Be easy to a share and reply to use.The VHDL adoption can build up various mold piece that can again make use of according to the design method of database(Library).These canned in advance design or use to design a medium backup mold a piece before and depositted these to the database in, can be in laterly of the design carry on replying to use, can make the design result be design the personnel's to carry on exchanges and share, decrease hardware electric circuit design.(1)compared with other hardware description languages, the VHDL have stronger behavior description ability, come to a decision him to become a system design realm the best hardware a description language thus.The strong behavior description ability is to avert from concrete spare part structure and describe and design important assurance of large-scale electronics system from the logic behavior.(2)the VHDL be abundant of imitate true language sentence and database function, make in any big system of the design can inspect a function possibility of design the system in early days, can carry on imitating true emulation to the design at any time.(3)the ability and procedure structure of the behavior description with lexical VHDL come to a decision the decomposition that he has to support a large-scale design with have already have design of again make use of function.Meet the market demanding large-scale system efficiently, the completion of the high speed has to include many people the several generation hair set even together and abreast works and then can carry out.(4)for use the design of an assurance of VHDL completion, can make use of EDA tool to carry on logic comprehensive with excellent turn, and auto of the VHDL describe the design change into the door class net form.(5)the description of VHDL to design have opposite and independent, the design can not understand the structure of hardware and need not manage the target spare part that the end design carry out, either is what, but carry on an independent design.Founded in 1981, this year has entered the Mentor of 25 years, is the oldest in the three major electronic design automation (EDA) vendors, and turnover ahead of a competitor four times, in addition to Mentor system design tools, market share, ranking first in the world, especially in the PCB layout, Mentor strengths which also ranked first in the world, its turnover is a full 1.5 times the second supplier. To assist customers in China "audiovisual" application-specific markets, "Technical Support" Mentor the largest part of human input (in the past each year is almost more than three times the rate of growth) in order to strengthen the ability of the Physical the Design and Functional Architecture ; and for the continued development of database management tool is also spared no effort in shipment volume growth of around 20% in the past five years, 15% of the revenue progress, is the fastest-growing EDA manufacturers.20世纪90年代，国际上电子和计算机技术较先进的国家，一直在积极探索新的电子电路设计方法，并在设计方法、工具等方面进行了彻底的变革，取得了巨大成功。
论文中英文翻译(译文)
编号：桂林电子科技大学信息科技学院毕业设计(论文)外文翻译（译文）系别：电子工程系专业：电子信息工程学生姓名：韦骏学号：0852100329指导教师单位：桂林电子科技大学信息科技学院姓名：梁勇职称：讲师2012 年6 月5 日设计与实现基于Modbus 协议的嵌入式Linux 系统摘要：随着嵌入式计算机技术的飞速发展，新一代工业自动化数据采集和监测系统，采用核心的高性能嵌入式微处理器的，该系统很好地适应应用程序。
它符合消费等的严格要求的功能，如可靠性，成本，尺寸和功耗等。
在工业自动化应用系统，Modbus 通信协议的工业标准，广泛应用于大规模的工业设备系统，包括DCS，可编程控制器，RTU 及智能仪表等。
为了达到嵌入式数据监测的工业自动化应用软件的需求，本文设计了嵌入式数据采集监测平台下基于Modbus 协议的Linux 环境采集系统。
串行端口的Modbus 协议是实现主/从式，其中包括两种通信模式：ASCII 和RTU。
因此，各种药膏协议的设备能够满足串行的Modbus通信。
在Modbus 协议的嵌入式平台实现稳定和可靠。
它在嵌入式数据监测自动化应用系统的新收购的前景良好。
关键词：嵌入式系统，嵌入式Linux，Modbus 协议，数据采集，监测和控制。
1、绪论Modbus 是一种通讯协议，是一种由莫迪康公司推广。
它广泛应用于工业自动化，已成为实际的工业标准。
该控制装置或不同厂家的测量仪器可以链接到一个行业监控网络使用Modbus 协议。
Modbus 通信协议可以作为大量的工业设备的通讯标准，包括PLC，DCS 系统，RTU 的，聪明的智能仪表。
随着嵌入式计算机技术的飞速发展，嵌入式数据采集监测系统，使用了高性能的嵌入式微处理器为核心，是一个重要的发展方向。
在环境鉴于嵌入式Linux 的嵌入式工业自动化应用的数据，一个Modbus 主协议下的采集监测系统的设计和实现了这个文件。
因此，通信设备，各种药膏协议能够满足串行的Modbus。
电子信息工程毕业设计外文翻译
xx大学毕业设计外文翻译系别职业技术教育学院专业电子信息工程班级电子Z091 学号 x姓名 x指导教师 x2013年5月16日MM420 inverter energy-saving measures in the water supply system-Nanjing Hangda Yihang Technology Co., Ltd.Because the frequency conversion velocity modulation does not need to construct the tradition for the aqueous system for the aqueous system top digit water tank, the water tank, avoided two times polluting and reducing the construction investment, moreover designed reasonably can achieve the good energy conservation effect.In gives in the aqueous system, the constant speed pump only then in its highly effective section movement can guarantee the system normal work also does not have the energy dissipation.In the design, (this time current capacity is generally biggest by the pipe network most unfavorable situation, must lift is also biggest) takes the choice water pump unit the main basis, but when the pipe network current capacity reduces, the energy waste is inevitable, when also possibly creates the low current capacity in pipeline overpressure question.The water pump basis system current capacity real-time change realization stepless speed regulation movement, is solves above problem well, achieves one of energy conservation goal ways.The water pump velocity modulation may through the very many way realization, in which frequency conversion velocity modulation be the present ideal one kind.The frequency conversion velocity modulation is through will give on the aqueous system pipe network the pressure transmitter to carry on the sampling to the pipe network hydraulic pressure, transforms the pressure signal into the electrical signal, and delivers to the PID regulator and the user establishment value of pressure it carries on the comparison and the operation, finally will transform for the frequency control signal delivers to the frequency changer.The frequency changer basis transmits frequency control signal adjustment water pump electrical machinery supply frequency, thus realizes adjusts the water pump the rotational speed.May divide into two kinds according to the customer in actual use request frequency conversion velocity modulation for the aqueous system: The live pressure variable gives the aqueous system for the aqueous system and the constant pressure variable.The live pressure variable establishes for the aqueous system pressure transmitter in the service pipe net terminal, the PID regulator setting value the service flood peakvalue which needs for the pipe network terminal user.The system causes the pipe network terminal hydraulic pressure maintenance through the automatic control to be constant, causes the pipeline characteristic curve and system static lifting is invariable, but the water pump water outlet pressure changes along with the volume of diversion change according to the pipeline characteristic curve, therefore theoretically realized “the system to need how many, the unit provided how many”, could not because the volume of diversion reduced has unnecessary static lifting, the energy conservation effect was satisfied.But this is only one kind of ideal situation, also in the system only has the frequency conversion pump alone to work.Because the frequency conversion equipment quite is expensive, large-scale often uses the frequency conversion pump and the constant speed pump parallel operation way water supply for the aqueous system.Presently establishes a frequency conversion pump and a power frequency pump and the combined transport behavior example by the system in.When the pipe network current capacity reduces, needs to lift reduces correspondingly, the frequency conversion pump may through the deceleration movement realization.But also must reduce correspondingly for guarantee parallel unit normal work power frequency pump lifting, this only can through increase the current capacity realization, thus creates the water volume the dropout, also possibly causes the power frequency pump to leave the highly effective section work, namely has not achieved the true energy conservation the goal.Meets has above situation, may take following measure to improve its energy conservation effect:①Gives the aqueous system regarding the small scale, may only suppose a frequency conversion pump, and causes the pump the highly effective area (its highly effective scope to move the time scope compared to power frequency pump to want as far as possible many including to appear the probability big operating point in a big way).②Uses the multi-Taiwan pump velocity modulation movement, certainly, quite is expensive as a result of the frequency conversion speeder price, should overall evaluation its economic agent decide.③When choice power frequency pump, should cause the system when the most disadvantageous spot work, the power frequency pump operating point approaches left side of as far as possible its highly effective area; If the most unfavorable situation appears the probability to be small, may enable it to deviate slightly the highlyeffective area, falls in the highly effective area left flank.Thus, when system lifting reduces, the power frequency pump still may in the highly effective area work.The constant pressure variable is located in the water pump unit water outlet for the aqueous system the pressure transmitter, is for the purpose of causing the water pump water outlet pressure maintenance to be constant, general hypothesis for most disadvantageous operating mode when the water pump water outlet needs the value of pressure.Still by a frequency conversion pump and a power frequency pump and combined transport behavior example.When the pipe network current capacity reduces, the frequency conversion pump through the deceleration movement, maintenance lifting invariable reduces the water discharge.Because the outlet pressure is invariable, the power frequency pumps out the water volume not to be able to change (i.e. movement operating mode invariably), still in highly effective area work, thus achieves the energy conservation goal.Needs to point out, the system needs when the current capacity changes small, the water pump water outlet pressure (still for the most unfavorable situation in system needs pressure) to be bigger than the pressure which the pipeline this time needs, thus still could cause static lifting to a certain extent the waste.Following two measures may improve its energy conservation effect:①Enlarges the pipe network suitably the caliber, causes the pipeline characteristic curve to hasten gently, but this can increase the pipe network the disposable investment, needs and the energy conservation effect makes the comprehensive economical comparison.②When choice power frequency pump causes each pump the operating point to fall as far as possible on the highly effective area.For aqueous system when water used trough (for example at night), in the system the water consumption is very small, even achieved the zero current capacity, is called “the micro current capacity”.In this case, if depends upon at the highly effective area great current capacity scope movement water pump maintains the system pressure, not only buckle water pump life, moreover the efficiency is low, cannot achieve the energy conservation the goal.Theoretically, the frequency conversion pump current capacity may approach in the highly effective scope in the zero, but in fact the water pump rotational speed not impossible unlimited to reduce, only depends on the frequency conversion pump to be competent the micro current capacity operating mode with difficulty toward the dealings.The actual project uses generally when the system additionally builds the small current capacity power frequency auxiliary pump,small current capacity facilities and so on frequency conversion auxiliary pump, barometric pressure pot maintain the micro current capacity the system pressure.To the different system micro current capacity question should the special details concrete analysis, and carries on the overall evaluation to the disposable investment and the long-term operating cost to be able to make the reasonable solution.In the frequency conversion velocity modulation for in the aqueous system design process, should choose the pump reasonably according to the service pipe net characteristic, achieved in satisfies the operation requirements under the premise, both saves the goal which the investment and conserves energy.MM420变频器在给水系统的几点节能措施-南京航大意航科技股份有限公司由于变频调速给水系统不需要建造传统给水系统的高位水箱、水塔，避免了二次污染并减少了土建投资，而且设计得合理能达到较好的节能效果。
电子信息工程外文翻译--使用自适应预测和自适应算术编码的有损图像的无损压缩
中文3595字附录B 外文参考文献Lossless Image Compression with Lossy Image Using AdaptivePrediction and Arithmetic CodingSeishi Taka and Mikio TakagiInstitute of Industrial Science,University of TokyoAbstractLossless gray scale image compression is necessary in many purposes, such as medical image, image database and so on. Lossy image is important as well, because of its high compression ratio. In this paper, we propose a Lossless image compression Scheme using a lossy image generated with PEG-DCT scheme. Our concept is, send a PEG-compressed lossy image primary, then send residual information and reconstruct the original image using both the lossy image and residual information. 3-dimensional adaptive prediction and an adaptive arithmetic coding are used, which fully uses the statistical parameter of distribution of symbol source. The optimal number of neighbor pixels and lossy pixels used for prediction is discussed. The compression ratio is better than previous work and quite close to the originally Lossless algorithm.IntroductionToday there are many studies on image compression, particularly on lossy and very low bit rate compression. For image database, such high compression ratio is Important for storage and also for quick transmission,but to deal with various kinds of users demand, Lossless image transmission is indispensable.In this paper, we propose an effective Lossless compression algorithm for gray image using lossy compressed image. The lossy compression scheme uses the Joint Photographic Experts Group discrete cosine transform (PEG-DCT) algorithm as the lossy coding algorithm.First we search the similar pairs of pixels (conlexts), according to their neighbor pixels. For such pixels which have contexts,we predict their values from the contexts and the neighbors. On the other hand, for each pixel which doesn't have its context pairs, we calculate the edge level according to the difference of adjacent pixel values. For each edge level of pixels, we calculate the predictive coefficients of linear combination under the least square error criterion. Not only the pixels which havealready processed but also the pixels of the lossy image is used for prediction.For every pixel, the difference between predicted value and real value iscalculated, and the difference is converted to anon-negative value before beingencoded, according to their distribution. In entropy coding stage,we use the arithmeticcoding. It is made adaptive,and initialerror distribution is given only by one para meter, which is specific for each edgelevel's statistical distribution. The pixels belonging to the difference edge levels areencoded independently.Experimental results and good performance are shown. Like the otherLPL(L0ssy Plus Lossless) approaches, our compression ratio is less than that oforiginally Lossless scheme,but the difference is slight. Of all things, however, usersget the great merit That they can browse the image before the Losslessdecompression.Many such schemes have been proposed in the literature, but most ofthem treat the lossy image and its Lossless residual as independent symbol source.One of the exceptions is Mem on ’s algorithm[6]. We utilize the lossy datathoroughly,and much better result is obtained.1.1 Pixel estimationNormally the image data is scanned along the scan-line direction.In figure 1.current pixel is processed pixels are .Ordinal pixel estimation method predicts the NFL,value of current pixel usingPI .. .P 4 . Then calculate the prediction error e=-. Normally the linear combinationis used for prediction as follows,where TI . . .T4 are the coefficients. This Figure 1:Current pixel is the extrapolative prediction.processed neighbor pixels=c t p t p t p t p ++++44332211(1)Usually, the zero-order entropy of set {e} is lower than that of set {z}.Therefore,after entropy coding scheme such as Huffman coding[l] or Arithmetic coding[2] orLempel-Ziv coding[3], data size is reduced.Principally, we also use the linear combination like equation (1) for prediction,but the process is more adaptive than normal prediction method. And we use moreneighbor pixels (up to ten), also using the pixels of lossy image and prediction error eis converted to another form before encoding.2.1 Grouping the pixels^x x x ^Each image pixel has different property under certain criterion. From a point of image compression, grouping similar pixels and encode them together causes effectiveresult. For grouping the pixels, we use the Q value:Q=|||||pppp|pp|pp|15141312-+-+-+-(2)Using this Q value, we classify each pixel into several groups according to table 1Table 1:Grouping tableFigure 2: (a)Original image ‘Girl’and (b)JPEG compressed image(qua1ity value=5)Figure 3: (a)Image of Q value, (b)Image of prediction error of simple predictionFigure 3(a)shows the Q value and (b) shows the error of simple prediction.As canbe seen from them, the value Q correlate closely with the prediction error. Therefore the prediction coefficients are calculated independently in each group.2.2 Context searchTable 2 shows each group ’s final zero-order entropy of prediction result of image ‘Girl ’. Obviously,the upper groups are more difficult to be compressed than the lower groups. We use the context-based prediction method to deal with such upper groups.The region where we search the similar area (we denote this “context ”)is shown in figure 4. This is restricted within already processed pixels ’area. The procedure is Described below:1. Scan the area and find points that satisfy70)('>x Q and10|)()(|'<-x Q x Q (3)2. Within such points, find one that minimizes||||-||a -b |-|-||a c a b ''''a c C --+= (4)3. If the C min is smaller than 12, treat it as the context of the current point.Otherwise, return failure (not found).2.3 Prediction2.3.1 Prediction of normal groupsFor each group,we predict the value of a current pixel by linear combination of itsneighbors ’ pixel values. The coefficients are calculated by least square error method. The neighbor pixels used for prediction are shown in figure 5 (Pi ...Pia).Number ofpixels are variable (up to 10pixels), and afterwards we will choose it optimumly. The priority is shown by the suffix number in the figure. The most effective number willbe discussed later.Table 2: Group V .S. Entropy (image ‘Girl ’)Figure 4: Context-search region Figure 5: Pixels used forpredictionHere, some of the lossy pixels (RI. . .&,) got from PEG-compressed image areAlso used. Using these pixels, something like interpolative prediction is achieved.This prediction contributes the reduction of compressed size.2.3.2 Prediction of contextUnder the criterion of condition (3) and (4). a pair of context have thesimilar shapes of height. Therefore, we predict the value 2 from {a ’,b ’, c ‘, z‘, a,b, c}(see figure4). We also use the least square error estimation. The mostdifferent point from prediction of non-context pixels is, not only using the values ofneighbor pixels but also using the closest context. This scheme is effective forcontinuous edges,because nearby an edge there is a sequence of similar lookingpixels.2.4 Error conversionIf each pixel has 8 bits, the prediction error e=-can have the real numberbetween -255 and +255 (roughly). After prediction, e should be expressed as aninteger. One easy way for conversion is, simply round the value off the integer(calculate Le +0.51) and consider it as the 2’s complement 8-bit number.Our conversion algorithm is totally based on Tanigu chi ’s method[5]. After this conversion,we can also get the 8-bit non-negative integer E. First we obtainthe upper and lower bound of the group (max, min).Then, according to the figure 6,convert the actual pixel value into integer. (In this figure, if actual pixel is equal to “ax ’, E = 9.) For each group,we get the maximum and minimum pixel value andconvert the prediction error respectively. This conversion is reversible. f you get thepredicted value and the converted number E (and also upper and lower bound), youcan obtain the actual pixel value from similar numerical line.2.5 Adaptive arithmetic coding2.5.1 Fitting of the distribution of EAccording to the experimental result, the distribution of E(figure7(a)), aftererror conversion, looks very close to the right half of a Gaussian distribution:)2e x p ()2(1222f )(2σπσσx x -= (5)^x xFigure 6: Algorithm of error conversion (example)Figure 7: (a)Distribution of E (image=‘Moon ’), (b)Fitting of Ewhere the variance is 2σ.As this distribution is limited right half, 2σis equal to , where N isthe number of samples. The fitting line (estimated frequency)of E ’s distribution is Calculated )(f 22x N σ.Their graphs are shown in figure 7(b). You can see that using this Gaussian model,the distribution of E is approximated well.2.5.2 Adaptive arithmetic codingThe probability density function of this fitting curve can be expressed by only oneparameter 2σ.This distribution is used to generate the initial distribution table for encoder(and also or decoder), instead of passing the large amount of actual frequency table. For this purpose, arithmetic coding is very suitable. For this purpose, our coderis made adaptive, each symbol from the data stream renews the frequency table. By using 2σand adaptive arithmetic coder,even small amount of data is coded with high coding rate.Experimental ResultsTo generate a lossy image, we adopt the JPEG compression scheme. The reasonis that P E G is the standard scheme for still image compression and users car1 find PEG-tools easily.We use the tools named ‘cjpeg’and ‘djpeg’, which is the products of IndependentP E G Group. To create the P E G image, cjpeg -quality quality-value -optimize filename and to decompress the P E G file, djpegipeg-file is invoked. The option ’-optimize performs optimization of entropy encoding parameters. It usually makes the P E G file a little smaller. ‘djpeg’has the optionTable 3: Effect of context search (N=9, N L 4 , quality=5)‘block smooth’,which performs cross-block smoothing,but from experimental results,it made the compression ratio worse, therefore this option is not used. Parameters which are necessary for decompression are put together and also encoded by adaptive arithmetic coder. Only several percent compression is achieved, but better than doing nothing.3.1 Effect of context searchWe use three test images ‘Girl’, ‘Couple’and ‘Moon’,which are chosen from SIDBA(Standard Image Data Base).For these images, the bit rate of compressing with and without context search is compared. The results are shown in table 3. NL is the number of lossy pixels used for prediction. N is the number of Lossless neighbor pixels.3.2 Effect of the quality value on compression ratioP E G provides a fine tuning factor (quality value),which corresponds to different Qualities of the compressed images. For typical image data, a low quality value such as 20provideshigh compression with poor image fidelity. As the quality value increases the fidelity improves at the expense of compression ratio.Figure 8 shows the bit rate and quality value. As the quality value decreases, the total bit rate decreases,too. Later we use the image quality value of 5,which is enough for understanding the image roughly (see figure 2(b)).Figure 8: Bit rate V.S.Quality value Figure 9: Bit rate V.S. NL (N=10,(N=10, -9,images‘Gir1’) quality=5, image=‘Girl ’)Table 4: Result of bit rate (quality=5, N=9, NL=4)3.3 Effect of using a lossy imageThere might be a doubt that the lossy image looks similar with the original to our eyes, but differs much from a standpoint of pixel-value, therefore it hardly helps the prediction.Figure9 shows the bit rate and the number of lossy pixels used for prediction(NL).From this figure, it is known even the poor image (quality=5) helps the compression ratio considerably.There as on why the bit rate increases gradually where NL is greaterthan 4 is, that additional parameter (coefficients)is necessary for each pixel position. The optimum NL is 4. Moreover we conducted experiments to find the optimum number of N. and obtained9.3.4 Comparison with the other methodsTable 4 shows the result of the compression. Taniguchi’s method[5] is originally Lossless oriented one, therefore the results are slightly better than ours. In our method, N and NL are set optimally.MAW method is proposed by Memon[6]. It also uses a lossy P E G image toreconstruct a Lossless image. Our result is about0.5 bit/pel better than MAW, and 0.03 to 0.12 bid\pel worse than Taniguchi’s method. As the MAW’S result is given only by entropy, the difference of performance from ours might be bigger.ConclusionIn this paper, we proposed the algorithm of Lossless image compression. Unlike other literatures,we have discussed not only the entropy of residual,but how to encode it efficiently and the final size of the compressed product. This provides an attractive option in applications that have need for quick transmission on the one hand and exact Reconstruction on the other. Furthermore,using this lossy image thoroughly, the total bit rate is considerably low.Searching the contexts and using it for prediction is proved to work.We will research more effective way of using context.Our algorithm is applicable for originally Lossless oriented one (not using lossyimage). In some images,we have obtained better results than Taniguchi’s method. We are proceeding the investigation in this standpoint.We are examining if there is a more suitable algorithm for lossy compression other than P E G . And also speculating the more accurate error distribution fitting other than Gaussian model.References[11 D. A. Huffman:“A method for the construction of minimum redundancy codes”,Proceedings of IRE40,pp. 41 1420,1951[2] J. J. Rissanenet al.: “Arithmetic coding”,IBM Journalor Research and Development, 23(2),pp. 188-193,1976[3] J. Ziv and A. Lempel: “A Universal Algorithm for Sequential Data Compression”, IEEE Transactions on Information Theory,IT-23(3), pp. 337-343, May 1997 [4] Paul G. Howard and Jefferey Scott Vitter: “New Methods for Lossless Image Compression Using Arithmetic Coding”, Proceedings of Data Compression Conference ’91,pp. 257-266.199 1[5] Takayuki Taniguchietal.: “Variable-Length-Code-Selective Reversible Predictive Coding for Multi-Level Images”,The Transactions of the Institute of Electronics, Information and Communication Engineers,V ol.J70-B, pp.654-663, Jun. 1987[6] Nasir D. Memon et al.:“Simple method for enhancing the performance of lossy plus Lossless image compression schemes”, Journal of Electronic Imaging 2(3), pp. 245-252, Jul. 1993[71 DmitryA. Novik: “Compression Through Decompression into Browse and Residual Images”, Proceedings of 1993 Space and Earth Science Data Compression Workshop, NASA Conference Publication3191,pp. 7-12, Apr. 1993使用自适应预测和自适应算术编码的有损图像的无损压缩摘要多用无损灰度图像压缩是必要的，如医学图像，图像数据库等。
毕业设计(论文)外文资料翻译(学生用)
毕业设计外文资料翻译学院：信息科学与工程学院专业：软件工程姓名： XXXXX学号： XXXXXXXXX外文出处： Think In Java (用外文写)附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂，而且极易出错。
程序员必须掌握与网络有关的大量细节，有时甚至要对硬件有深刻的认识。
一般地，我们需要理解连网协议中不同的“层”（Layer）。
而且对于每个连网库，一般都包含了数量众多的函数，分别涉及信息块的连接、打包和拆包；这些块的来回运输；以及握手等等。
这是一项令人痛苦的工作。
但是，连网本身的概念并不是很难。
我们想获得位于其他地方某台机器上的信息，并把它们移到这儿；或者相反。
这与读写文件非常相似，只是文件存在于远程机器上，而且远程机器有权决定如何处理我们请求或者发送的数据。
Java最出色的一个地方就是它的“无痛苦连网”概念。
有关连网的基层细节已被尽可能地提取出去，并隐藏在JVM以及Java的本机安装系统里进行控制。
我们使用的编程模型是一个文件的模型；事实上，网络连接（一个“套接字”）已被封装到系统对象里，所以可象对其他数据流那样采用同样的方法调用。
除此以外，在我们处理另一个连网问题——同时控制多个网络连接——的时候，Java内建的多线程机制也是十分方便的。
本章将用一系列易懂的例子解释Java的连网支持。
15.1 机器的标识当然，为了分辨来自别处的一台机器，以及为了保证自己连接的是希望的那台机器，必须有一种机制能独一无二地标识出网络内的每台机器。
早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。
但Java面向的是整个因特网，这要求用一种机制对来自世界各地的机器进行标识。
为达到这个目的，我们采用了IP（互联网地址）的概念。
IP以两种形式存在着：(1) 大家最熟悉的DNS（域名服务）形式。
我自己的域名是。
所以假定我在自己的域内有一台名为Opus的计算机，它的域名就可以是。
单片机基础毕业设计外文翻译
本科生毕业设计（论文）外文翻译毕业设计题目：外文题目：Fundamentals of Single-chip Microcomputer 译文题目：单片机基础学院：信息科学与工程学院专业班级：电子信息工程0802班学生姓名：指导教师：外文原文Fundamentals of Single-chip MicrocomputerDr. Dobbs MacintoshJournalAbstractT h e s i n gl e-chi p m i c r o com pu t er i s t h e cul m i na t i on of bo t h t h e d e v el opm e nt o f t h e di gi t al c om p ut e r a nd t h e i nt e gra t e d c i r c ui t a rgu a b l y t h e t ow m o st s i gn i fi c ant i nv en t i on s of t h e 20t h ce n t u r y .T h es e t o w t yp e s o f a rc hi t e c t u r e a r e fo un d i n s i n gl e-c hi p m i c r o com pu t e r.S om e e m p l o y t h e s pl i t p ro gr a m/d at a m em o r y o f t h e H a r v a rd a r ch i t e ct u r e, s ho wn i n F i g.3-5A-1, ot h er s f o l l o w t he p hi l o so ph y,w i d e l y a d a p t ed f o r ge n e r al-pu rp os e com p ut e rs and m i c r op r oc e s s o rs,of m ak i n g n o l o gi c al di s t i nc t i on be t w ee n p ro gr a m a n d d at a m em o r y a s i n t h e P r i n c et on ar c hi t e ct u r e.In ge n e r a l t er m s a si n gl e-c hi p m i cro c om put e r i s c ha r ac t e ri z ed b y t h e i n co r po r at i o n o f al l t h e u ni t s o f a c om put e r i n t o a s i n gl e d e vi c e.Keyword: Single-chip Microcomputer ROM RAM Programming Algorithm Features• Compatible with MCS-51™ Products• 4K Bytes of In-System Reprogrammable Flash Memory– Endurance: 1,000 Write/Erase Cycles• Fully Static Operation: 0 Hz to 24 MHz• Three-level Program Memory Lock• 128 x 8-bit Internal RAM• 32 Programmable I/O Lines• Two 16-bit Timer/Counters• Six Interrupt Sources• Programmable Serial Channel• Low-power Idle and Power-down ModesDescriptionThe AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4Kbytes of Flash programmable and erasable read only memory (PEROM). The deviceis manufactured using Atmel’s high-density nonvolatile memory technology and iscompatible with the industry-standard MCS-51 instruction set and pinout. Theon-chipFlash allows the program memory to be reprogrammed in-system or by a conventionalnonvolatile memory programmer. By combining a versatile 8-bit CPU with Flashon a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which providesa highly-flexible and cost-effective solution to many embedded control applications.The AT89C51 provides the following standard features: 4Kbytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bittimer/counters, a five vector two-level interrupt architecture,a full duplex serial port, on-chip oscillator and clock circuitry.In addition, the AT89C51 is designed with static logicfor operation down to zero frequency and supports twosoftware selectable power saving modes. The Idle Modestops the CPU while allowing the RAM, timer/counters,serial port and interrupt system to continue functioning. ThePower-down Mode saves the RAM contents but freezesthe oscillator disabling all other chip functions until the nexthardware reset.Pin ConfigurationsBlock DiagramPin DescriptionVCCSupply voltage.GNDGround.Port 0Port 0 is an 8-bit open-drain bi-directional I/O port. As anoutput port, each pin can sink eight TTL inputs. When 1sare written to port 0 pins, the pins can be used as highimpedanceinputs.Port 0 may also be configured to be the multiplexed loworderaddress/data bus during accesses to external programand data memory. In this mode P0 has internalpullups.Port 0 also receives the code bytes during Flash programming,and outputs the code bytes during programverification. External pullups are required during program verification.Port 1Port 1 is an 8-bit bi-directional I/O port with internal pullups.The Port 1 output buffers can sink/source four TTL inputs.When 1s are written to Port 1 pins they are pulled high bythe internal pullups and can be used as inputs. As inputs,Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2Port 2 is an 8-bit bi-directional I/O port with internal pullups.The Port 2 output buffers can sink/source four TTL inputs.When 1s are written to Port 2 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @DPTR). In this application, it uses strong internal pullups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register.Port 2 also receives the high-orderaddress bits and some control signals during Flash programming and verification.Port 3Port 3 is an 8-bit bi-directional I/O port with internal pullups.The Port 3 output buffers can sink/source four TTL inputs.When 1s are written to Port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functions of various special features of the AT89C51 as listed below:Port 3 also receives some control signals for Flash programmingand verification.ALE/PROGAddress Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.In normal operation ALE is emitted at a constant rate of 1/6the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory.If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSENProgram Store Enable is the read strobe to external program memory.When theAT89C51 is executing code from external programmemory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.EA/VPPExternal Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH.Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require 12-volt VPP.XTAL1Input to the inverting oscillator amplifier and input to the internal clock operating circuit.XTAL2Output from the inverting oscillator amplifier.Oscillator CharacteristicsXTAL1 and XTAL2 are the input and output, respectively,of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2. There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed.Idle ModeIn idle mode, the CPU puts itself to sleep while all the onchip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special functions registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset. It should be noted that when idle is terminated by a hard ware reset, the device normally resumes programexecution,from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a port pin when Idle is terminated by reset, the instruction following the one that invokes Idle should not be one that writes to a port pin or to external memory.Figure 1. Oscillator ConnectionsFigure 2. External Clock Drive ConfigurationPower-down ModeIn the power-down mode, the oscillator is stopped, and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values until the power-down mode is terminated. The only exit from power-down is a hardware reset. Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize.Program Memory Lock BitsOn the chip are three lock bits which can be left unprogrammed (U) or can be programmed (P) to obtain the additional features listed in the table below.When lock bit 1 is programmed, the logic level at the EA pin is sampled and latched during reset. If the device is powered up without a reset, the latch initializes to a random value, and holds that value until reset is activated. It is necessary that the latched value of EA be in agreement with the current logic level at that pin in order for the device to function properly.Programming the FlashThe AT89C51 is normally shipped with the on-chip Flash memory array in the erased state (that is, contents = FFH) and ready to be programmed. The programming interface accepts either a high-voltage (12-volt) or a low-voltage (VCC) program enable signal. The low-voltage programming mode provides a convenient way to program theAT89C51 inside the user’s system, while the high-voltage programming mode is compatible with conventional thirdparty Flash or EPROM programmers. The AT89C51 is shipped with either the high-voltage or low-voltage programming mode enabled. The respective top-side marking and device signature codes are listed in the following table.The AT89C51 code memory array is programmed byte-bybyte in either programming mode. To program any nonblank byte in the on-chip Flash Memory, the entire memory must be erased using the Chip Erase Mode.Programming Algorithm: Before programming the AT89C51, the address, data and control signals should be set up according to the Flash programming mode table and Figure 3 and Figure 4. To program the AT89C51, take the following steps.1. Input the desired memory location on the address lines.2. Input the appropriate data byte on the data lines.3. Activate the correct combination of control signals.4. Raise EA/VPP to 12V for the high-voltage programming mode.5. Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-write cycle is self-timed and typically takes no more than 1.5 ms.Repeat steps 1 through 5, changing the address and data for the entire array or until the end of the object file is reached.Data Polling: The AT89C51 features Data Polling to indicate the end of a write cycle. During a write cycle, an attempted read of the last byte written will result in the complement of the written datum on PO.7. Once the write cycle has been completed, true data are valid on all outputs, and the next cycle may begin. Data Polling may begin any time after a write cycle has been initiated.Ready/Busy: The progress of byte programming can also be monitored by theRDY/BSY output signal. P3.4 is pulled low after ALE goes high during programming to indicate BUSY. P3.4 is pulled high again when programming is done to indicate READY.Program Verify: If lock bits LB1 and LB2 have not been programmed, the programmed code data can be read back via the address and data lines for verification. The lock bits cannot be verified directly. Verification of the lock bits is achieved by observing that their features are enabled.Chip Erase: The entire Flash array is erased electrically by using the proper combination of control signals and by holding ALE/PROG low for 10 ms. The code array is written with all “1”s. The chip erase operation must be executed before the code memory can be re-programmed.Reading the Signature Bytes: The signature bytes are read by the same procedure as a normal verification of locations 030H, 031H, and 032H, except that P3.6 and P3.7 must be pulled to a logic low. The values returned are as follows.(030H) = 1EH indicates manufactured by Atmel(031H) = 51H indicates 89C51(032H) = FFH indicates 12V programming(032H) = 05H indicates 5V programmingProgramming InterfaceEvery code byte in the Flash array can be written and the entire array can be erasedby using the appropriate combination of control signals. The write operation cycle is selftimed and once initiated, will automatically time itself to completion. All major programming vendors offer worldwide support for the Atmel microcontroller series. Please contact your local programming vendor for the appropriate software revision.外文资料翻译译文单片机基础摘要：单片机是电脑和集成电路发展的巅峰，有据可查的是它们也是20世纪最意义的两大发明。
电子信息工程外文翻译--杜比实验室谈杜比
毕业设计(论文)外文资料翻译系别：信息专业：电子信息工程班级： 081姓名：学号：附件：1.外文资料翻译译文；2外文原文指导教师评语：签名：年月日Dolby laboratory on DolbyAuthor: TigerMultichannel perceptual codingDolby AC-3is a kind of efficiency, quality and functional aspects with unprecedented effect perceptual digital audio coding technology. From the beginning of 1992, it has been for the cinema provide multichannel digital audio system and achieved in 1994into the two channel I BS application. It in the cassette and disc type family television system for transmitting multichannel digital sound function has been to the consumer electronics industry with very excited. In the United States, high definition television ( HDTV ) broadcasting the selected Dolby digital surround sound transmission, estimated that in 1996will be put into a test screening.Many have been announced and the potential applications of the technology of test shows, Dolby AC-3decoder has a beautifully versatility. AC-3 is not a single machine system, but a kind of use can make such as bit rate and number of channels such parameters to adapt to different special application flexible procedures for the treatment of familial. Various types of all decoder in order to work on the same principle as the foundation, and designed to take full account of the future need for compatibility and adaptability. Important is, Dolby AC-3will be high quality sound and excellent digital efficiency is very perfect combination. Because of the Dolby Laboratory for more than 20 years focus on human auditory research, in the development of signal processing field has accumulated rich experience, so, although AC-3than in the CD disk to the last channel lower bit rate to create a multi-channel surround sound, however, it makes the sound quality fully meet the listener expectations.Audio : past present and futureIn 30, the famous Baer Laboratories began using the three channel stereo sound. In 50, when the stereo into public movie, it uses the channel in four above, sometimes reaching over seven channels. A few years later, the stereo into families, since all of the phonograph records only with dual channel matching, so the family leave acoustic device only by dual channel playback, the technical limitations, can not the listener will generally two-channel stereo as the home audio selection criteria.But the film makers have channel 1( left, right, center ) and surround channel2as a compelling vivid sound minimum requirements. This can be from 70 time end, eighty time period the film industry widely adopted Dolby stereo to record film confirmed, Dolby stereo is the principle, let four channel matrix coding input two optical sound track, then an appropriate audio processor will restore it into four channels matrix coding reproduction.When Dolby stereo film is converted into audio signals, four channel coding retained the dubbing integrity, from 80 time begin first, Dolby surround has made multiple channel decoding into family time, today, tens of thousands of home audio systems are equipped with Dolby surround sound system, in fact, multi-channel surround sound system sales has been farbeyond the two-channel stereo system sales, at present, Dolby surround sound has been widely used in film, TV and music on CD recording studio, and its accompanying family Dolby surround systems on the market rapid development.With multi-channel audio in consumer electronics in the field of rapid growth, a more advanced technology was born, the technology is born there is nothing comparable to this, it has simulated realistic sound effects, and can satisfy various listening conditions and high demand cannot imagine adaptability, this is Dolby AC-3decoding technology Dolby AC-3 decoder, the successful development and application, is the world's electro-acoustic industry a major achievement.Dolby AC-3In 1987, high-definition television channel in the United States has officially become the standard process, its audio track is used for the first time in the four channel matrix encoding conversion for transmission of digital code stereo. However, by 1990, in order to avoid audio matrix are affected, four mono or stereo combined configuration as the optimal configuration. Due to time technical limitations, such an arrangement would have to increase by at least a bit rate.It is in this context, Dolby AC-3was born. It has the advantage of only two independent stereo more code rates can realize multi-channel audio code. Dolby advanced to the transmission of the code technology, such as Dolby AC-2 decoder for Dolby AC-3's successful development paved the way, but the complexity of multichannel code also need further research, including a new type of bit allocation technique.The Dolby laboratory is established by Rui Milton Dolby. Dr. Dolby was born in 1933 in the United States Portland Oregon City, grew up in the San Francisco Bay area. At the age of 16 he was still in high school, in Ampex company works. The company is the United States 's first production of magnetic tape recording equipment manufacturers. Later, he is responsible for the development of the company developed the world's first practical VCR portion of an electronic circuit.In 1957 Dolby graduated from Stanford University, University of Cambridge, Marshall won the British provided scholarships, study of L-band X light. In 1961 he received a doctor's degree in physics. In 1963, he accepted the UN appointed to India as a two-year consultant.As an amateur recording enthusiasts, Dr. Dolby over the years to recognize on the tape recording audio or video signal when background noise on the recording quality damage. While in India he began thinking seriously about a noise reduction without compromising the recording quality approach. His exploration of these became the Dolby A B noise reduction and noise reduction, noise reduction system based on C.In 1965, returning to England, in London he established his own laboratory in order to carry out in India he thought scheme. Set up in 1968 to" the Dolby lab" named company. Although the company was founded10 years ago, the work of the centre in the UK, but it has been an American company. After 1976, the company's main work moved to San francisco.In 1965, the first Dolby A type noise reducer ( A representing audio Audio ) production out of. The design of the system for a variety of audio noise reduction application, especially can solve the studio recording tape when the tape recorder generated noise. Until 1966, there have beenseveral noise reducing technology available, but they are much to damage the recording quality. So Dr Dolby faced difficulty is how to make the personage inside course of study and potential customers to believe his technique. At that time, multitrack recorder, from the 4 rail, track 8, track 16to 24 track, start the application, when multitrack recording tape audio mixing, the mixing of the two track tape noise level than double direct recording of the master tape is much higher.In 1966January, Decca Records UK Department believes that Dolby A type noise reducer can indeed as Dr. Dolby described that play a role, and then ordered9Dolby A301A type noise reducer, applied for the first time in 1966May in Vienna to record Ashe Ken that Qi played some of Mozart's piano concerto. In 1966November, Decca published the first application of Dolby A type noise reducer record by Georg Solti / Muller second symphony. Subsequently, the recording industry began to recognize and use a large amount of Dolby A type noise reduction system. Initially used only recorded classical music, when multitrack recording technology promotion, will be more widely applied. Soon, the whole world of professional and non-professional begin to" Dolby" with high quality recording together.With the hope that Dolby will be present and noise reduction technology for civilian recorder voice rising, in an American commercial tape recorder manufacturer KLH company 's urging,1967April Dolby lab started to develop more practical civil noise reduction technology, initially known as the" simplified Dolby system", which later became known as Dolby B type noise reduction technology. In the Dolby B noise reduction technology development is nearing completion, Dr. Dolby made the decision, Dolby laboratory will not civilian production of audio products, consumer electronics products, but to the manufacturers authorized Dolby technology has been very mature, then by manufacturers for production. By the end of 1974, the Dolby laboratory authorized manufacturers already amounted to 47, including all consumer audio equipment manufacturers.Thereafter, Dolby laboratory has developed a series of Technology: C type noise reduction, SR ( spectral recording ), S type noise reduction, HXPro, stereo surround Dolby, Dolby, Dolby Pro Logic, AC1, AC2, Dolby digital ( AC3), Dolby E. These techniques are widely used in civil and professional audio equipment, sound recording film, cinema playback apparatus, digital broadcast etc..In addition to the headquarters in San Francisco, Dolby laboratory at present in the world have established branches or liaison offices: Losangeles, Wootton Barcelona ( UK), London, Brisbane, New York, Tokyo, Shanghai, Beijing, Hongkong.AC-3 multi-channel frameDolby surround ( Dolby Surround ) is the original Dolby multichannel film analog format consumer version. In the production of Dolby surround sound, a 4Channel -- left, right, and surround sound channel audio information through matrix coding in two tracks on a record. The two tracks from stereo format program source such as a video and television broadcast program and carrying into the family, and decoded the original 4channels of information can be reduced and surround sound. Hundreds of thousands of home videos and TV shows by Dolby surround coding." Dolby surround ( Dolby Surround ) as the most primary surround sound standard, provides a 4channel surround sound support.Dolby surround and DTS surround is similar in that they are lossy digital compression technology. This is referred to as" emotional" data compression technique is based on the human psychoacoustics that possess sound characteristics -- for high level sensitive voices, while shielding the other is not sensitive to the sound development of.Because Dolby stereo is a coding technology of digital stereo, and decoding technique uses a direction identifying circuit or a directional logic circuit, so that the use of Dolby company this circuit technology of sound is called Dolby Pro Logic sound; with Dolby 's proprietary specific decoding technology is called a Dolby Pro logic decoder decoder.Of course, only with the use of Dolby to the logic function of the AV amplifier, played by Dolby sound recording software, can hear the true high fidelity digital stereo sound effect. Dolby digital systems will generally be5.1 channel sound compression to 384bps, and some CD with 448bps, the maximum to the 640bps; DTS usually use much larger bit rate --1536bps. If other conditions are the same, is a bit more quality is better, this assertion is wrong? Unfortunately, the answer to this question is not so easy, because the Dolby Digital ( abbreviated as DD ) and DTS data compression circuit is different. For example, a coding efficiency very low signal, even if the bit rate is very high, also just wasted bits and disc space, but does not improve sound quality. Once a system is said to be" transparent", increase the bit rate without causing it to improve the sound quality. In addition because the DTS bit rate higher than Dolby, need takes up more space, if the DVD disk capacity constraints, may produce adverse effects on image quality, or to increase the additional cd.Dolby Pro-Logic surround sound ( Dolby Pro Logic ) is Dolby developed a surround sound system. It is the four track stereo recording by a specific encoding means for the synthesis of two channel, the original left channel ( L ), the right channel ( R ), the center channel ( C ), surround channel ( S ) of the 4signal, encoded into LT, RT composite double channel signal, replay through the decoder will encoded two-channel composite signals LT and RT reduction for encoding the left, right, in around four, each stem and independent signal, amplified respectively input left, right, center and surround sound speakers.In order to playback symmetry reasons, surround speakers using the left and right surround speakers, respectively, from the output of the amplifier, so the business to Dolby Pro-Logic surround sound output called channel five. But due to a left, right surround sound speakers connected in a channel, the output is the same as the surround channel information, the essence is still four channel. The business also has six channels and seven channels Dolby Pro Logic AV amplifier. The six track is the central channel two amplifying circuit is respectively connected with the output, in left center speaker and right center speaker. But left, right center speaker connected to a center channel, it is essentially a four channel. Seven channel surround sound channels is divided into four channel output, i.e. left rear surround, right rear surround sound, and adopts four surround sound, which became a seven channel output. But the output of the seven track four surround speakers are connected in a surround channel, also can calculate the output of four sound channels. So with Dolby Pro logic decoder AV amplifier whether five channel output, six channels of output or the seven output channels, is essentially a four channel. Dolby Pro-Logic surround sound in the left, right, three channel frequency range can reach 20-20000Hz, can meet the full range of requirements, but surround channel frequency range is narrow, only 100-7000Hz.Dolby E is designed for digital TV broadcast and post-production and the design of aprofessional audio coding system. Using the Dolby E, a AES / EBU channel can send up to 8channels of high quality digital audio stream, and also can be loaded Dolby digital control data signals (often called the metadata, including the Dolby digital mono mode, dynamic range, type, output level automatic adjustment of parameters, to ensure that users can correct Dolby digital program ). Dolby E with its advanced coding algorithm and higher data transmission rate, can ensure the digital TV audio signals through as many as 10cycle coding - decoding or other editing process, and does not cause quality deterioration. Dolby E audio can be associated with various formats of video signal is a good match, won't because video interference blind audio, sound burr or other distortion. Dolby E audio and video frames in the sequence are completely corresponding, can achieve precise audio and video integrated editing. More importantly, by use of this new type of coding technology, the existing radio and television system without large-scale transformation can spread multi-channel digital TV audio signals, thereby greatly reducing the system cost.Dolby E application is in digital television stations intermediate transfer, from a local television program transmitted by satellite to another local TV station. Dolby E in conveying to the transmitting terminal will be converted to PCM audio, and then encoded into Dolby digital signal, transmitted to thousands of households. Therefore, consumers in the home can be directly received by Dolby E signal, but only receives a digital signal on channel 5.1Dolby. In order to avoid the confusion, usually Dolby E called transfer coding system, and Dolby will be called to launch digital coding system.Dolby E standard data transfer rate is 1.92Mbits / sec (20bit / 48kHz for audio signal ), typical operating mode is "5.1+2", using six channel transmits a 5.1channel surround sound signal, the other two channel transmission of two-channel matrix coding signal ( such as Dolby Pro-Logic surround sound ) or dual mono stereo signal. Can also work in other modes, such as with two mono signal"5.1+1+1" pattern, three way stereo signal "3x 2" mode and a six single channel signal"6x 1" mode. Dolby's current version supports 29.97fps frame rate ( NTSC standard, PAL25FPS ),20bit length and 48kHz sampling frequency of the audio signal, a future version will support25FPS,16bit or24bit audio signal.AC-3 transmission formAC-3 based transmission system into a more extensive application field is feasible in technology. At the end of the century before, several AC-3 based application technology into commercial production.High definition television ( HDTV ) is declared using a AC-3 code first application technology. Grand Alliance has selected the United States developed this technique. For its high definition television system with digital surround sound and in 1996Atlanta Olympic Games for the first time as media.Because the AC-3effects and can be associated with high definition television matches the standard features of digital cable TV system, therefore, is a natural candidate for AC - 3. The first test transmission was 1994year. Due to the current available programs can use a single sound, stereo can also use with matrix ( matrix - sur-round ) stereo, therefore, a AC-3dual channel decoder for has been developed. And when the multi-channel digital program for transmission, high function converter ( converter ) will create a synthetic stereo downwardmixing effect.Always as home theater the highest quality image source DVD ( (LD ) as Dolby surround digital multi-channel audio examples show. Using AC-3bit stream ( bit stream ) alternative FM channel in a channel, so that the stereo pulse code modulation ( PCM ) digital audio soundtrack with FM mono cooperate with each other, so that it can be compatible with existing any player. With cable, DBS and DAB is realized by AC-3spectrum effect, quality and multi channel features a unique mix of choice. The first use of AC-3DBS system has been introduced in 1994, it can be for commercial organizations to provide a single transmitter transmission up to 120 stereo music channel transmission system.Other areas of application include medical telemetry devices suitable for very low bit-rate code under development. Potential users and system developers and the Dolby laboratory, in order to obtain the AC-3 technical support.AC-3 integrated circuitDolby surround digital main technical progress is Rolland ( Irap ) Company IR38000, which is a can perform AC-3decoder to decode single chip digital sound field processor ( DSP ). It was first used in second generation Dolby stereo digital cinema in the decoding unit.A Rolland company development, lower cost, especially suitable for consumer electronics equipment and also can provide the program logic decoding ( Pro Logic decoding ) AC--3 decoder integrated circuit in the middle of 1994launch. This is a dual channel integrated circuit chip can be used, such as cable television 's top decoder. Other semiconductor manufacturers have been or are ready to supply the AC-3 decoder integrated circuit.Dolby and digitalAC-3 is Dolby's laboratory developed the third generation of perceptual coding system. Each code system will be a special psychological acoustics ( psycho acoustics ) knowledge and advanced digital signal processing technology combine very well.AC-1 initially by the Australian Broadcasting Corporation in 1985 for its DBS system. Perhaps partly because AC-1 decoder cost reasons, it appears to be widely applied to other DBS services, satellite communication network and digital" wired broadcasting system". According to their different applications, each channel code rate for 220-325bit / sec. As an adaptation of delta modulation ( ADM ) in the form of a digital stream, ( datastream) contains information not by audio signal absolute value provided, but by different sampling ( Sample ) value changes identified. By Dolby transform to noise reduction techniques, such as: continuous transformation step and pre-emphasis can greatly improve the adaptation of delta modulation ( ADM ) basic performance.Dolby AC-2advanced adaptive transmission code used in professional audio transmission and storage, which each channel digital rate of 128 or192day / sec. Narrow band multiplicity of frequency control signal program fully adopted the noise masking superiority, resulting in an efficient reduction rate and high signal transparent effect. In other applications, such as: a long distance transmission, real time (real-time ) recording, mixing and adding storage ( ADR ) are very widely used for connecting remote recording studio or film shooting field. AC =3 is alsoused to connect the BBC Transmitter Room and the Dolby DSTLR system core equipment. AC-3 is in the AC-1and AC-2is developed on the basis of multi channel coding technology, to retain the original AC - 2such as window function, exponential transform coding, adaptive bit allocation and many other features, but also a new stereophonic sound channel coding technology strategy for the coupling and rematrix algorithm. In general, the stereo left channel and a right channel signal in the sense of hearing is very similar, there are many repetitive redundancy information, will be the two channel signals combine to be coded, can remove redundant signal and will not affect the original sound quality. Here AC-3array low bit rate and an effective means of.AC-3PC voice data input, output the compressed digital bit stream. Coding is the first step, using the TDAC ( Time Domain Aliasing Cancellation ) filter the time-domain PC sampling data is transformed into a frequency domain blocks into a series of transform coefficients, each transform coefficient in binary exponential notation, namely an exponent and a mantissa. Exponent part encoded constitutes the entire signal substantially the spectrum, also known as the spectral envelope. Using the spectrum including and shaded by line correlation decision each mantissa bit allocation. Because the bit allocation is adopted in the anterior / posterior to the hybrid adaptive bit allocation and public bit pool technology, which can make the limited rate in the channel between the different frequency components, between the rational allocation of the mantissa; in quantization process, the mantissa is shaking, shaking the pseudo random number generator can be on a different platform to get the same results. By the end of six blocks of the spectral envelope, coarse quantization of the mantissa and the corresponding parameters consisting of AC-3 data frame format, continuous frame merged into a digital stream output.By the time domain is transformed to the frequency domain block length selection is the exponential transform coding based on. As defined in AC-3two length switching, a512sample value point of the long block, a256sample value point of short block. In the analysis of signal spectrum, to deal with the channel signal blocks cut made longer, so that you can get a better frequency resolution, but also can get higher coding efficiency. But long data block may contain a number of different possible recognition of noise, such as pre-echo. That is to say the ear due to time and frequency exists on the shadowing effect in the exponential transform coding is a contradiction, not at the same time, must plan as a whole processing. For the steady state signal, whose frequency varies with time transform slow, in order to improve the coding efficiency, requirement filter has good frequency resolution, which requires a long block; as for the rapidly changing signal, requires good time resolution, which requires a short block. In the encoder, the input signal after3Hz high-pass filter removes the DC component, and then through a8kHz high-pass filter out high-frequency components, with its energy are compared with a preset threshold, in order to detect the signal transient situation.AC-3based on the modified discrete cosine transform ( MDCT ) adaptive transform coding ( ATC ) algorithm. Although defined in AC-3 standard MDCT transform, but the actual using a N / 4IFFT ( FFT ), plus two simple Pre-IFFT and Post-IFFT as adjustment, in order to achieve a N IMDCT transform. ATC algorithm is an important consideration is based on auditory masking effect critical band theory, namely in the critical band within a voice to another voice signal shielding effect the most obvious. Therefore, dividing the band filter group to have fast enough to ensure that critical band frequency response, and noise attenuation is large enough,the time and frequency of noise within the defined in the masking threshold.The AC-3 encoder bit allocation technique, has been applied widely on the forward and backward adaptive bit allocation rule. Forward adaptive bit allocation method is the encoder calculation, and the bit allocation information explicitly incorporated into the stream of data bits, and is characterized in that the front end of the encoding process uses auditory model, thus modifying the model the receiving side decoding process has no effect; the disadvantage of reducing coding efficiency, because of the need to transfer the bit allocation information while occupying a part effective bits. To the adaptive method did not get encoder clear bit allocation information, but from a digital stream in which the bit allocation information, has the advantages of no occupation of the effective bits, thus has higher transmission efficiency. Its drawback is from received data to calculate the bit allocation, if the calculation is too complex to the rising cost of decoder. In addition, the decoder algorithm also with encoder auditory model change. AC-3using hybrid backward / forward adaptive bit allocation, in enhancing the rate and reduce the cost of strikes a balance between.AC-3 decoder decoding principle basically is encoded by the reverse process, firstly, the decoder must with the encoded data stream synchronization, and then from a data error correction of digital flow separation control data, system configuration, the encoded spectral envelope and the quantized mantissas and other content, according to the sound spectrum envelope to generate the bit allocation information, the mantissa part of inverse quantization, restoring the transform coefficient exponent and mantissa, after synthesis filter banks, the data from the frequency domain to time domain, the final output of the PCM sample signal reconstruction.Through the understanding of AC-3, you can see the AC-3technology makes full use of the human ear sensory model, according to the different properties of signal, to take the corresponding effective algorithm, achieved at a high quality under the premise of achieving a higher rate for the intended purpose, is a very efficient and economical digital audio compression system. AC-3 is the American digital television system of mandatory standard, is the European digital television system recommended standard, at the same time, AC-3or DVD system of compulsory standards. At present our country is the development and promotion of digital TV system, all have reasons to believe that AC-3 technology will have a good prospect of application.Dolby Chun chamber ( About DolbyLaboratoies ) from the analog noise reduction ( analog noisereduction ) to the digital code ( digitalcode ), Dolby has concentrated on rooted in laboratory to ear sound perception based audio processing development. In the process of development, Dolby has always been the emphasis is on the critical listening and tested. Either analog or digital program program, their results are the same, with low cost, greatly improves the efficiency of communication media. In some cases, it also for the improvement of new products, such as: Dolby surround sound ( DolbySurround ) and home theater ( home theater T ) make contribution.The Dolby laboratory consists of the following components: investment and Technology Development Engineering Department, occupation audio product design and manufacturing sector, experts the organization and distribution of all over the world in the field of support group. Dolby products from companies located in modern American and British manufacturing plant. Lyrics by the world's major consumer electronics manufacturers group; for each license。
电子信息毕业设计外文翻译--微型计算机控制系统(单片机控制系统)
毕业设计外文资料翻译Graduation design foreign language translation学院：电气工程与自动化学院专业班级：电子信息科学与技术三班学生姓名：学号：指导教师：外文资料：Microcomputer SystemsElectronic systems are used for handing information in the most general sense; this information may be telephone conversation, instrument read or a company‟s accounts, but in each case the same main type of operation are involved: the processing, storage and transmission of information. in conventional electronic design these operations are combined at the function level; for example a counter, whether electronic or mechanical, stores the current and increments it by one as required. A system such as an electronic clock which employs counters has its storage and processing capabilities spread throughout the system because each counter is able to store and process numbers.Present day microprocessor based systems depart from this conventional approach by separating the three functions of processing, storage, and transmission into different section of the system. This partitioning into three main functions was devised by V on Neumann during the 1940s, and was not conceived especially for microcomputers. Almost every computer ever made has been designed with this structure, and despite the enormous range in their physical forms, they have all been of essentially the same basic design.In a microprocessor based system the processing will be performed in the microprocessor itself. The storage will be by means of memory circuits and the communication of information into and out of the system will be by means of special input/output(I/O) circuits. It would be impossible to identify a particular piece of hardware which performed the counting in a microprocessor based clock because the time would be stored in the memory and incremented at regular intervals but the microprocessor. However, the software which defined the system‟s behavior would contain sections th at performed as counters. The apparently rather abstract approach to the architecture of the microprocessor and its associated circuits allows it to be very flexible in use, since the system is defined almost entirely software. The design process is largely one of software engineering, and the similar problems of construction and maintenance which occur inconventional engineering are encountered when producing software.The figure1-1 illustrates how these three sections within a microcomputer are connected in terms of the communication of information within the machine. The system is controlled by the microprocessor which supervises the transfer of information between itself and the memory and input/output sections. The external connections relate to the rest (that is, the non-computer part) of the engineering system.Fig.1-1 Three Sections of a Typical Microcomputer Although only one storage section has been shown in the diagram, in practice two distinct types of memory RAM and ROM are used. In each case, the word …memory‟ is rather inappropriate since a computers memory is more like a filing cabinet in concept; information is stored in a set of numbered …boxes‟ and it is referenced by the serial number of the …box‟ in question.Microcomputers use RAM (Random Access Memory) into which data can be written and from which data can be read again when needed. This data can be read back from the memory in any sequence desired, and not necessarily the same order in which it was written, hence the expres sion …random‟ access memory. Another type of ROM (Read Only Memory) is used to hold fixed patterns of information which cannot be affected by the microprocessor; these patterns are not lost when power is removed and are normally used to hold the program which defines the behavior of a microprocessor based system. ROMs can be read like RAMs, but unlike RAMs they cannot be used to store variable information. Some ROMs have their data patterns put in during manufacture, while others are programmable by the user by means of special equipment and are called programmable ROMs. The widely used programmable ROMs are erasable by means of special ultraviolet lamps and are referred to as EPROMs, short for Erasable Programmable Read Only Memories. Other new types of device can be erased electrically without the need for ultraviolet light, which are called Electrically Erasable Programmable Read OnlyMemories, EEPROMs.The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor.The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor.The microprocessor , memory and input/output circuit may all be contained on the same integrated circuit provided that the application does not require too much program or data storage . This is usually the case in low-cost application such as the controllers used in microwave ovens and automatic washing machines . The use of single package allows considerable cost savings to e made when articles are manufactured in large quantities . As technology develops , more and more powerful processors and larger and larger amounts of memory are being incorporated into single chip microcomputers with resulting saving in assembly costs in the final products . For the foreseeable future , however , it will continue to be necessary to interconnect a number of integrated circuits to make a microcomputer whenever larger amounts of storage or input/output are required.Another major engineering application of microcomputers is in process control. Here the presence of the microcomputer is usually more apparent to the user because provision is normally made for programming the microcomputer for the particular application. In process control applications the benefits lf fitting the entire system on to single chip are usually outweighed by the high design cost involved, because this sort lf equipment is produced in smaller quantities. Moreover, process controllers are usually more complicatedso that it is more difficult to make them as single integrated circuits. Two approaches are possible; the controller can be implemented as a general-purpose microcomputer rather like a more robust version lf a hobby computer, or as a …packaged‟ system, signed for replacing controllers based on older technologies such as electromagnetic relays. In the former case the system would probably be programmed in conventional programming languages such as the ones to9 be introduced later, while in the other case a special-purpose language might be used, for example one which allowed the function of the controller to be described in terms of relay interconnections, In either case programs can be stored in RAM, which allows them to be altered to suit changes in application, but this makes the overall system vulnerable to loss lf power unless batteries are used to ensure continuity of supply. Alternatively programs can be stored in ROM, in which case they virtually become part of the electronic …hardware‟ and are often referred to as firmware. More sophisticated process controllers require minicomputers for their implementation, although the use lf large scale integrated circuits …the distinction between mini and microcomputers, Products and process controllers of various kinds represent the majority of present-day micro computer applications, the exact figures depending on one‟s interpretation of the word …product‟. Virtually all engineering and scientific uses of microcomputers can be assigned to one or other of these categories. But in the system we most study Pressure and Pressure Transmitters. Pressure arises when a force is applied over an area. Provided the force is one Newton and uniformly over the area of one square meters, the pressure has been designated one Pascal. Pressure is a universal processing condition. It is also a condition of life on the planet: we live at the bottom of an atmospheric ocean that extends upward for many miles. This mass of air has weight, and this weight pressing downward causes atmospheric pressure. Water, a fundamental necessity of life, is supplied to most of us under pressure. In the typical process plant, pressure influences boiling point temperatures, condensing point temperatures, process efficiency, costs, and other important factors. The measurement and control of pressure or lack of it-vacuum-in the typical process plant is critical.The working instruments in the plant usually include simple pressure gauges, precision recorders and indicators, and pneumatic and electronic pressure transmitters. A pressure transmitter makes a pressure measurement and generates either a pneumatic orelectrical signal output that is proportional to the pressure being sensed.In the process plant, it is impractical to locate the control instruments out in the place near the process. It is also true that most measurements are not easily transmitted from some remote location. Pressure measurement is an exception, but if a high pressure of some dangerous chemical is to be indicated or recorded several hundred feet from the point of measurement, a hazard may be from the pressure or from the chemical carried.To eliminate this problem, a signal transmission system was developed. This system is usually either pneumatic or electrical. And control instruments in one location. This makes it practical for a minimum number of operators to run the plant efficiently.When a pneumatic transmission system is employed, the measurement signal is converted into pneumatic signal by the transmitter scaled from 0 to 100 percent of the measurement value. This transmitter is mounted close to the point of measurement in the process. The transmitter output-air pressure for a pneumatic transmitter-is piped to the recording or control instrument. The standard output range for a pneumatic transmitter is 20 to 100kPa, which is almost universally used.When an electronic pressure transmitter is used, the pressure is converted to electrical signal that may be current or voltage. Its standard range is from 4 to 20mA DC for current signal or from 1 to 5V DC for voltage signal. Nowadays, another type of electrical signal, which is becoming common, is the digital or discrete signal. The use of instruments and control systems based on computer or forcing increased use of this type of signal.Sometimes it is important for analysis to obtain the parameters that describe the sensor/transmitter behavior. The gain is fairly simple to obtain once the span is known. Consider an electronic pressure transmitter with a range of 0～600kPa.The gain isdefined as the change in output divided by the change in input. In this case, the output is electrical signal (4～20mA DC) and the input is process pressure (0～600kPa). Thus the gain. Beside we must measure Temperature Temperature measurement is important in industrial control, as direct indications of system or product state and as indirect indications of such factors as reaction rates, energy flow, turbine efficiency, and lubricant quality. Present temperature scales have been in use for about 200 years, the earliestkPamA kPa mA kPa kPa mA mA Kr 027.0600160600420==--=instruments were based on the thermal expansion of gases and liquids. Such filled systems are still employed, although many other types of instruments are available. Representative temperature sensors include: filled thermal systems, liquid-in-glass thermometers, thermocouples, resistance temperature detectors, thermostats, bimetallic devices, optical and radiation pyrometers and temperature-sensitive paints.Advantages of electrical systems include high accuracy and sensitivity, practicality of switching or scanning several measurements points, larger distances possible between measuring elements and controllers, replacement of components(rather than complete system), fast response, and ability to measure higher temperature. Among the electrical temperature sensors, thermocouples and resistance temperature detectors are most widely used.DescriptionThe AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel‟s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications. Function characteristicThe AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.Pin DescriptionVCC：Supply voltage.GND：Ground.Port 0：Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as highimpedance inputs.Port 0 may also be configured to be the multiplexed loworder address/data bus during accesses to external program and data memory. In this mode P0 has internal pullups.Port 0 also receives the code bytes during Flash programming,and outputs the code bytes during programverification. External pullups are required during programverification.Port 1Port 1 is an 8-bit bi-directional I/O port with internal pullups.The Port 1 output buffers can sink/source four TTL inputs.When 1s are written to Port 1 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2Port 2 is an 8-bit bi-directional I/O port with internal pullups.The Port 2 output buffers can sink/source four TTL inputs.When 1s are written to Port 2 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 2 pins that are externally being pulled low will source current, because of the internal pullups.Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses. In this application, it uses strong internal pullupswhen emitting 1s. During accesses to external data memory that use 8-bit addresses, Port 2 emits the contents of the P2 Special Function Register.Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.Port 3Port 3 is an 8-bit bi-directional I/O port with internal pullups.The Port 3 output buffers can sink/source four TTL inputs.When 1s are written to Port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functionsof various special features of the AT89C51 as listed below:Port 3 also receives some control signals for Flash programming and verification.RSTReset input. A high on this pin for two machine cycles while the oscillator is running resets the device.ALE/PROGAddress Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory.If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSENProgram Store Enable is the read strobe to external program memory.When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.EA/VPPExternal Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset.EA should be strapped to VCC for internal program executions.This pin also receives the 12-volt programming enable voltage(VPP) during Flash programming, for parts that require12-volt VPP.XTAL1Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2Output from the inverting oscillator amplifier.Oscillator CharacteristicsXTAL1 and XTAL2 are the input and output, respectively,of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1.Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2.There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed.中文翻译：微型计算机控制系统（单片机控制系统）广义地说，微型计算机控制系统（单片机控制系统）是用于处理信息的，这种被用于处理的信息可以是电话交谈，也可以是仪器的读数或者是一个企业的帐户，但是各种情况下都涉及到相同的主要操作：信息的处理、信息的存储和信息的传递。
外文翻译--基于51单片机温度报警器的设计(适用于毕业论文外文翻译+中英文对照)
外文翻译--基于51单片机温度报警器的设计(适用于毕业论文外文翻译+中英文对照)XXX: Design of a Temperature Alarm Based on 51 MCUDepartment: n EngineeringMajor: Measurement and Control Technology and nClass:Student ID:Name:Supervisor:Date:A microcontroller。
also known as a single-chip computer system。
XXX its ns being integrated on a small chip。
it has most of the components needed for a complete computer system。
such as CPU。
memory。
internal and external bus systems。
and mostof them also have external storage。
At the same time。
it integrates XXX interfaces。
timers。
real-time clocks。
etc。
The most XXX integrate sound。
image。
ork。
and complex input-output systems on a single chip.XXX used in the industrial control field。
Microcontrollers XXX CPUs inside the chip。
The original design concept was to integrate a large number of peripheral devices and CPUs on a chip to make the computer system XXX's Z80 was the first processor designed according to this concept。
外文翻译--燃气报警器
外文翻译--燃气报警器福州大学至诚学院本科生毕业设计（论文）外文翻译题目：基于单片机可燃气体检测报警器的设计姓名：蔡佳阳学号： 211014128系别：信息工程系专业：电子信息工程年级： 2010级指导教师：（签名）年月日附录：外文文献及译文外文原文1 ：Combustible gas alarmCombustible gas alarmto prevent gas leakage as a powerful weapon, it has, however, does not seem to have attracted the attention it deserves. This security and household fire extinguishers can be placed on a par, or even more than the fire extinguisher into the family of the little things that most families do not see it as one thing, do not even know there can be such a fundamental solution to gas poisoning and gas explosion, "the protection of God" exists. Shanghai as an example, last year, due to poisoning and cooking gas water heater overflow out, piece of rubber hose off the aging caused by gas leakage and poisoning caused by a total of 86 deaths, accounting for all the gas data of accidents were 84%. However, according to an authoritative department to another survey released shows that in Shanghai, about three million gas users, the installation of domesticgas leakage alarm of less than 10%.In their daily lives, whether it is gas poisoning or gas explosion, because of gas leak into the sky. Home life, no one is inseparable from the use of gas, no matter what you do more preventive measures, but a hundred secret inevitably very careful, not to mention of any fire safety measures are not taken on even more dangerous family. Therefore it is necessary to prepare a Combustible gas at home at any time for the owner guardian of the gas appliances, a gas alert to this invisible killer slipped quietly out to help the owner of the elimination offamily problems in the bud, the domestic security of the good housekeeper, so that family members with the use of gas, the use of hearts at ease. For example, there are many families of fire gas explosion, do not know in the room full of gas leaking out, the blind use of electricalswitches and tragedy in an instantif there is an alarm, a tragedy like this ,can be greatly avoided.Combustible gas alarm into the family, will become a good home security to help, this is an indisputable fact Product Description:Detection of gas: natural gas, liquefied petroleum gas, city gas (H2)Size: 115mm * 71mm * 43.3mm(1) add automatic sensor drift compensation, the real and omitted to prevent the false positives.(2) The failure prompted the police to enable the user to replace and repair, to prevent the non-reported.(3) MCU control the entire process, working temperature -40 degrees to 80 degrees. Operating voltage: 220V AC or 110V AC, 12VDC-20VDC Additional features: linkage exhaust fan, the manipulator, the solenoid valveNetworking: wired networking functions: (NO, NC) Wireless networking: 315MHZ/433MHZ (2262 OR 1527)译文：燃气报警器燃气报警器作为预防燃气泄漏的有力武器，它的出现却似乎并没有引起人们应有的注意。
【计算机专业文献翻译】信息系统的管理
传播媒体必须经过仔细选择，平衡每个媒体的优点和缺点，这个选择决定网络的速度。改变一个已经安装好的网络媒体通常非常昂贵。最实用的传播媒体是电缆，光纤，广播，光，红外线。
本科生毕业设计（论文）外文资料译文
（2009届）
论文题目
基于Javamail的邮件收发系统
学生姓名
学号
专业
计算机科学与技术
班级
指导教师
职称
讲师、副教授
填表日期
2008年 12月 10 日
信息科学与工程学院教务科制
外文资料翻译（译文不少于2000汉字）
1．所译外文资料：信息系统的管理Managing Information Systems
数据共享是网络的重要应用之一。网络可以共享交易数据，搜索和查询数据，信息，公告板，日历，团队和个人信息数据，备份等。在交易的时候，连接一个公司的电脑的中央数据库包括现有库存信息和出售的数据信息。如果数据被储存在一个中央数据库中，搜查结果便可从中获取。电子邮件的发送已经成为同事之间最常用的信息共享的方式之一。
自从信号在空中传输后，广播，光以及红外线作为传播媒体已经不需要电缆。
传输能力，即一个传播媒体一次性传输的数据量，在不同的媒体中，材料不同，安装时付出的劳动不同，传输的能力有很大的区别。传播媒体有时候被合并，代替远地域之间的高速传播媒体，速度虽慢，但是成本低，在一幢大楼中进行信息传播。
连接设备包括网络连接卡NICS，或者在计算机和网络间进行传输和信号传递的局域网LAN卡。其他常用的设备连接不同的网络，特别是当一个网络使用不用的传输媒体的时候。使用一个对很多用户都开放的系统很重要，比如windows/NT,Office2000，Novell，UNIX.
电子信息工程专业毕设 文献翻译 附英文原文
5.3. 时钟独立的显性误差
对于每一个特定的GPS时钟，在每个适用的时间从KF1相位偏差估计值减去 UECC估计值， 去估计其OEIC的相位。 在测量加工， OEIC包含在几部分纳秒内(见 图4)。图4展示了的两种情况下地面工作站时钟S1的OEIC。在蓝线的可见区间和 KF1测距处理显然有别于没有测量的传播间隔。在测量处理期间，KF1估计误差 的观察目标部分包含在几部分纳秒内。OEIC的协方差顺序计算需要每个时间点 的 KF1相位偏差估计误差和UECC估计误差的互协方差矩阵值。 我尚未能计算这
X K 1|K 1 X K 1|K K K 1[ y K 1 y( X K 1|K )]
Hale Waihona Puke （5）5. 难以观察的 GPS 时钟系统
GPS时间是由作战空军（USAF）卡尔曼滤波器处理 GPS伪距测量产生的。 GPS时间是多个GPS时钟的平均相位， 可是， 通过 GPS伪距测量， 每个运行的GPS 时钟的时钟相位是难以观察的，演示如下。GPS导航星的轨道参数是从GPS伪距 观测可观察到的。从GPS伪距测量可以得到USAF（美国空军）卡尔曼滤波器估 计轨道参数和时钟同步参数， 因此以这种方式将状态估计值分为隐式的时钟参数 子集和显式的轨道参数子集。通过应用谢尔曼有关MU函数的定理，演示了这种 分区方式。
4.3.2. 非线性函数 MU
计算 n ×1 矩阵滤波器增益 K K 1 ：
T T 1 K K 1 PK 1|K H K 1 [ H K 1 PK 1| K H K 1 R K 1 ]
（4）
滤波器测量更新 n×1 状态估计矩阵 X K 1|K 1 ，观测 yK+1 得
态估计误差协方差方阵（正特征值）
外文翻译----调幅无线电
毕业设计/论文外文文献翻译系别信息科学与技术系专业班级电子信息工程0601调幅无线电历史无线电的历史及早期的无线电电台可以追溯到20世纪前八十年，利用调幅无线电通信进行广播是非常有效的方式，进入二十一世纪，这一方式，仍被广泛采用。
调幅广播开始的第一次，是在圣诞前夕的1906年由加拿大研究者Reginald Fessenden 实验播出，并直至第一次世界大战，用它进行了小规模的语音和音乐播放。
旧金山，加利福尼亚州电台KCBS自称是KQW的继承者，由无线电实验者Charles "Doc" Herrold，在加利福尼亚州圣何塞建立的，每周定期播出的广播成立于1909年6月。
在此基础上KCBS自称是世界上最古老的广播站，并在2009年夏天庆祝成立100周年。
第一次世界大战后，随着无线电试验站在世界范围的广泛增多，调幅无线电的应用得到了广泛地增加，第一次的调幅无线电商业广播服务始于20世纪20年代。
Montreal XWA，Quebec （后来的CFCF，现在的CINW）宣称作为世界第一大商业电视台的地位，于1920年5月20日开始正式广播。
首家拥有正常营业执照的美国电台由Frank Conrad, KDKA 在Pittsburgh, Pennsylvania开始营业，无线电节目的大发展还是在“ 无线电黄金时代”（20世纪20-50年代）。
这一时期戏剧，喜剧和所有其他形式的娱乐都相继得到创造发展，而广播新闻和音乐也不例外。
调幅收音机的技术要比调频收音机、DAB、卫星广播和高清广播简单得多。
一个调幅接收器在一个特定频率检测无线电波的振幅变化。
然后通过放大信号电压来驱动扬声器或耳机。
最早的晶体收音机接收器使用没有放大功能的晶体二极管探测器。
在北美的广播实践，商业调幅电台传到天线的发射功率从约250瓦-5万瓦特。
实验许可证上表明最多发出五十万瓦特辐射功率，在灾害时期，包括广域通信的通信站，包括Cincinnati的通信站 WLW，这种辐射功率一直到第二次世界大战前都在用。
电子信息工程专业外文翻译----一个高效率的CMOS超宽带信号产生模块
毕业设计（论文）外文翻译资料翻译资料名称(外文) A Power-Efficient CMOS UWBSignal-Generation Module翻译资料名称(中文)一个高效率的CMOS超宽带信号产生模块电子信息工程院（系）电子信息工程专业学号B06093011学生姓名指导教师起讫日期2009. 2. 23 ~ 2009. 6. 4设计地点中文译文一个高效率的CMOS超宽带信号产生模块摘要这篇论文提出了一个新的载波超宽带发射机结构，同时给出了它的CMOS实现结构。
这新的发射机拓扑结构采用一个两级开关。
它增强了射频功率效率，降低了直流功率的损耗和电路的复杂性。
发射机使用0.18μm CMOS工艺实现，超宽带信号生成模块包括一个超宽带SPST开关和一个可调脉冲发生器。
测量结果表明，产生10dB可变的超宽带信号，其信号带宽从0.5GHz变化到4GHz，并且调谐中心频率覆盖了整个超宽带频率，即从3.1GHz到10.6GHz。
CMOS模块直流功耗小于2mW。
本文中提出的载波超宽带发射机和论证的模块提供了一个对超宽带信号产生有吸引力的方法，同时他们可以应用于超宽带通信和雷达。
1、引言超宽带技术获得重大的利益，尤其是在1998年的FCC的调查公告和在2002年在3.1-10.6GHz频段中无牌使用超宽带设备的调查与整治。
超宽带技术是有前途的技术，它的能力包括准确的定位和高效短距离点对点网络以及高分辨率遥感。
载波超宽带信号已广泛应用于各种雷达和通信系统中。
通过天线它们拥有更加方便的频谱管理和减少失真的优势。
在典型的超宽带发射机中，生成载波的超宽带电压信号必须被发射到一个宽带功率放大器，从而获得达到所需的功率水平。
这个方法有两个重要的缺点：第一，超宽带功率放大器的设计挑战；第二，在低脉冲重复频率中的低功率效率。
在本文中，提出了一种新的载波超宽带发射机结构。
它不仅仅提高了功率效率，而且减少电路的复杂性。
同时文章论证了新的CMOS发射机模块性能可操作性和性能，频率覆盖了整个3.1GHz到10.6GHz的超宽带频带和可变带宽500MHz到4GHz。
毕业设计英文 翻译(原文)
编号：毕业设计(论文)外文翻译（原文）院（系）：桂林电子科技大学专业：电子信息工程学生姓名： xx学号： xxxxxxxxxxxxx 指导教师单位：桂林电子科技大学姓名： xxxx职称： xx2014年x月xx日Timing on and off power supplyusesThe switching power supply products are widely used in industrial automation and control, military equipment, scientific equipment, LED lighting, industrial equipment,communications equipment,electrical equipment,instrumentation, medical equipment, semiconductor cooling and heating, air purifiers, electronic refrigerator, LCD monitor, LED lighting, communications equipment, audio-visual products, security, computer chassis, digital products and equipment and other fields.IntroductionWith the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly close, and electronic equipment without reliable power, into the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer Power new generation to enter the switching power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, communications, electronic testing equipment power control equipment, power supply, etc. have been widely used in switching power supply, but also to promote the rapid development of the switching power supply technology .Switching power supply is the use of modern power electronics technology to control the ratio of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation (PWM) ICs and switching devices (MOSFET, BJT) composition. Switching power supply and linear power compared to both the cost and growth with the increase of output power, but the two different growth rates. A power point, linear power supply costs, but higher than the switching power supply. With the development of power electronics technology and innovation, making the switching power supply technology to continue to innovate, the turning points of this cost is increasingly move to the low output power side, the switching power supply provides a broad space for development.The direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switching power supply into a wider range of application areas, especially in high-tech fields, and promote the miniaturization of high-tech products, light of. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.classificationModern switching power supply, there are two: one is the DC switching power supply; the other is the AC switching power supply. Introduces only DC switching power supply and its function is poor power quality of the original eco-power (coarse) - such as mains power or battery power, converted to meet the equipment requirements of high-quality DC voltage (Varitronix) . The core of the DC switching power supply DC / DC converter. DC switching power supply classification is dependent on the classification of DC / DC converter. In other words, the classification of the classification of the DC switching power supply and DC/DC converter is the classification of essentially the same, the DC / DC converter is basically a classification of the DC switching power supply.DC /DC converter between the input and output electrical isolation can be divided into two categories: one is isolated called isolated DC/DC converter; the other is not isolated as non-isolated DC / DC converter.Isolated DC / DC converter can also be classified by the number of active power devices. The single tube of DC / DC converter Forward (Forward), Feedback (Feedback) two. The double-barreled double-barreled DC/ DC converter Forward (Double Transistor Forward Converter), twin-tube feedback (Double Transistor Feedback Converter), Push-Pull (Push the Pull Converter) and half-bridge (Half-Bridge Converter) four. Four DC / DC converter is the full-bridge DC / DC converter (Full-Bridge Converter).Non-isolated DC / DC converter, according to the number of active power devices can be divided into single-tube, double pipe, and four three categories. Single tube to a total of six of the DC / DC converter, step-down (Buck) DC / DC converter, step-up (Boost) DC / DC converters, DC / DC converter, boost buck (Buck Boost) device of Cuk the DC / DC converter, the Zeta DC / DC converter and SEPIC, the DC / DC converter. DC / DC converters, the Buck and Boost type DC / DC converter is the basic buck-boost of Cuk, Zeta, SEPIC, type DC / DC converter is derived from a single tube in this six. The twin-tube cascaded double-barreled boost (buck-boost) DC / DC converter DC / DC converter. Four DC / DC converter is used, the full-bridge DC / DC converter (Full-Bridge Converter).Isolated DC / DC converter input and output electrical isolation is usually transformer to achieve the function of the transformer has a transformer, so conducive to the expansion of the converter output range of applications, but also easy to achieve different voltage output , or a variety of the same voltage output.Power switch voltage and current rating, the converter's output power is usually proportional to the number of switch. The more the number of switch, the greater the output power of the DC / DC converter, four type than the two output power is twice as large,single-tube output power of only four 1/4.A combination of non-isolated converters and isolated converters can be a single converter does not have their own characteristics. Energy transmission points, one-way transmission and two-way transmission of two DC / DC converter. DC / DC converter with bi-directional transmission function, either side of the transmission power from the power of lateral load power from the load-lateral side of the transmission power.DC / DC converter can be divided into self-excited and separately controlled. With the positive feedback signal converter to switch to self-sustaining periodic switching converter, called self-excited converter, such as the the Luo Yeer (Royer,) converter is a typical push-pull self-oscillating converter. Controlled DC / DC converter switching device control signal is generated by specialized external control circuit.the switching power supply.People in the field of switching power supply technology side of the development of power electronic devices, while the development of the switching inverter technology, the two promote each other to promote the switching power supply annual growth rate of more than two digits toward the light, small, thin, low-noise, high reliability, the direction of development of anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, AC / AC DC / AC, such as inverters, DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardization, and has been recognized by the user, but AC / DC modular, its own characteristics make the modular process, encounter more complex technology and manufacturing process. Hereinafter to illustrate the structure and characteristics of the two types of switching power supply.Self-excited: no external signal source can be self-oscillation, completely self-excited to see it as feedback oscillation circuit of a transformer.Separate excitation: entirely dependent on external sustain oscillations, excited used widely in practical applications. According to the excitation signal structure classification; can be divided into pulse-width-modulated and pulse amplitude modulated two pulse width modulated control the width of the signal is frequency, pulse amplitude modulation control signal amplitude between the same effect are the oscillation frequency to maintain within a certain range to achieve the effect of voltage stability. The winding of the transformer can generally be divided into three types, one group is involved in the oscillation of the primary winding, a group of sustained oscillations in the feedback winding, there is a group of load winding. Such as Shanghai is used in household appliances art technological production of switching power supply, 220V AC bridge rectifier, changing to about 300V DC filter added tothe collector of the switch into the transformer for high frequency oscillation, the feedback winding feedback to the base to maintain the circuit oscillating load winding induction signal, the DC voltage by the rectifier, filter, regulator to provide power to the load. Load winding to provide power at the same time, take up the ability to voltage stability, the principle is the voltage output circuit connected to a voltage sampling device to monitor the output voltage changes, and timely feedback to the oscillator circuit to adjust the oscillation frequency, so as to achieve stable voltage purposes, in order to avoid the interference of the circuit, the feedback voltage back to the oscillator circuit with optocoupler isolation.technology developmentsThe high-frequency switching power supply is the direction of its development, high-frequency switching power supply miniaturization, and switching power supply into the broader field of application, especially in high-tech fields, and promote the development and advancement of the switching power supply, an annual more than two-digit growth rate toward the light, small, thin, low noise, high reliability, the direction of the anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, the DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardized, and has been recognized by the user, but modular AC / DC, because of its own characteristics makes the modular process, encounter more complex technology and manufacturing process. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.The switching power supply applications in power electronic devices as diodes, IGBT and MOSFET.SCR switching power supply input rectifier circuit and soft start circuit, a small amount of applications, the GTR drive difficult, low switching frequency, gradually replace the IGBT and MOSFET.Direction of development of the switching power supply is a high-frequency, high reliability, low power, low noise, jamming and modular. Small, thin, and the key technology is the high frequency switching power supply light, so foreign major switching power supply manufacturers have committed to synchronize the development of new intelligent components, in particular, is to improve the secondary rectifier loss, and the power of iron Oxygen materials to increase scientific and technological innovation in order to improve the magnetic properties of high frequency and large magnetic flux density (Bs), and capacitor miniaturization is a key technology. SMT technology allows the switching power supply has made considerable progress, the arrangement of the components in the circuit board on bothsides, to ensure that the light of the switching power supply, a small, thin. High-frequency switching power supply is bound to the traditional PWM switching technology innovation, realization of ZVS, ZCS soft-switching technology has become the mainstream technology of the switching power supply, and a substantial increase in the efficiency of the switching power supply. Indicators for high reliability, switching power supply manufacturers in the United States by reducing the operating current, reducing the junction temperature and other measures to reduce the stress of the device, greatly improve the reliability of products.Modularity is the overall trend of switching power supply, distributed power systems can be composed of modular power supply, can be designed to N +1 redundant power system, and the parallel capacity expansion. For this shortcoming of the switching power supply running noise, separate the pursuit of high frequency noise will also increase, while the use of part of the resonant converter circuit technology to achieve high frequency, in theory, but also reduce noise, but some The practical application of the resonant converter technology, there are still technical problems, it is still a lot of work in this field, so that the technology to be practical.Power electronics technology innovation, switching power supply industry has broad prospects for development. To accelerate the pace of development of the switching power supply industry in China, it must take the road of technological innovation, out of joint production and research development path with Chinese characteristics and contribute to the rapid development of China's national economy.Developments and trends of the switching power supply1955 U.S. Royer (Roger) invented the self-oscillating push-pull transistor single-transformer DC-DC converter is the beginning of the high-frequency conversion control circuit 1957 check race Jen, Sen, invented a self-oscillating push-pull dual transformers, 1964, U.S. scientists canceled frequency transformer in series the idea of switching power supply, the power supply to the size and weight of the decline in a fundamental way. 1969 increased due to the pressure of the high-power silicon transistor, diode reverse recovery time shortened and other components to improve, and finally made a 25-kHz switching power supply.At present, the switching power supply to the small, lightweight and high efficiency characteristics are widely used in a variety of computer-oriented terminal equipment, communications equipment, etc. Almost all electronic equipment is indispensable for a rapid development of today's electronic information industry power mode. Bipolar transistor made of 100kHz, 500kHz power MOS-FET made, though already the practical switching power supply is currently available on the market, but its frequency to be further improved. Toimprove the switching frequency, it is necessary to reduce the switching losses, and to reduce the switching losses, the need for high-speed switch components. However, the switching speed will be affected by the distribution of the charge stored in the inductance and capacitance, or diode circuit to produce a surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Which, in order to prevent the switching Kai - closed the voltage surge, RC or LC buffers can be used, and the current surge can be caused by the diode stored charge of amorphous and other core made of magnetic buffer . However, the high frequency more than 1MHz, the resonant circuit to make the switch on the voltage or current through the switch was a sine wave, which can reduce switching losses, but also to control the occurrence of surges. This switch is called the resonant switch. Of this switching power supply is active, you can, in theory, because in this way do not need to greatly improve the switching speed of the switching losses reduced to zero, and the noise is expected to become one of the high-frequency switching power supply The main ways. At present, many countries in the world are committed to several trillion Hz converter utility.the principle of IntroductionThe switching power supply of the process is quite easy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the PWM switching power supply to the power transistor turns on and off state, in both states, on the power transistor V - security product is very small (conduction, low voltage, large current; shutdown, voltage, current) V oltammetric product / power device is power semiconductor devices on the loss.Compared with the linear power supply, the PWM switching power supply more efficient process is achieved by "chopping", that is cut into the amplitude of the input DC voltage equal to the input voltage amplitude of the pulse voltage. The pulse duty cycle is adjusted by the switching power supply controller. Once the input voltage is cut into the AC square wave, its amplitude through the transformer to raise or lower. Number of groups of output voltage can be increased by increasing the number of primary and secondary windings of the transformer. After the last AC waveform after the rectifier filter the DC output voltage.The main purpose of the controller is to maintain the stability of the output voltage, the course of their work is very similar to the linear form of the controller. That is the function blocks of the controller, the voltage reference and error amplifier can be designed the same as the linear regulator. Their difference lies in the error amplifier output (error voltage) in the drive before the power tube to go through a voltage / pulse-width conversion unit.Switching power supply There are two main ways of working: Forward transformand boost transformation. Although they are all part of the layout difference is small, but the course of their work vary greatly, have advantages in specific applications.the circuit schematicThe so-called switching power supply, as the name implies, is a door, a door power through a closed power to stop by, then what is the door, the switching power supply using SCR, some switch, these two component performance is similar, are relying on the base switch control pole (SCR), coupled with the pulse signal to complete the on and off, the pulse signal is half attentive to control the pole voltage increases, the switch or transistor conduction, the filter output voltage of 300V, 220V rectifier conduction, transmitted through the switching transformer secondary through the transformer to the voltage increase or decrease for each circuit work. Oscillation pulse of negative semi-attentive to the power regulator, base, or SCR control voltage lower than the original set voltage power regulator cut-off, 300V power is off, switch the transformer secondary no voltage, then each circuit The required operating voltage, depends on this secondary road rectifier filter capacitor discharge to maintain. Repeat the process until the next pulse cycle is a half weeks when the signal arrival. This switch transformer is called the high-frequency transformer, because the operating frequency is higher than the 50HZ low frequency. Then promote the pulse of the switch or SCR, which requires the oscillator circuit, we know, the transistor has a characteristic, is the base-emitter voltage is 0.65-0.7V is the zoom state, 0.7V These are the saturated hydraulic conductivity state-0.1V-0.3V in the oscillatory state, then the operating point after a good tune, to rely on the deep negative feedback to generate a negative pressure, so that the oscillating tube onset, the frequency of the oscillating tube capacitor charging and discharging of the length of time from the base to determine the oscillation frequency of the output pulse amplitude, and vice versa on the small, which determines the size of the output voltage of the power regulator. Transformer secondary output voltage regulator, usually switching transformer, single around a set of coils, the voltage at its upper end, as the reference voltage after the rectifier filter, then through the optocoupler, this benchmark voltage return to the base of the oscillating tube pole to adjust the level of the oscillation frequency, if the transformer secondary voltage is increased, the sampling coil output voltage increases, the positive feedback voltage obtained through the optocoupler is also increased, this voltage is applied oscillating tube base, so that oscillation frequency is reduced, played a stable secondary output voltage stability, too small do not have to go into detail, nor it is necessary to understand the fine, such a high-power voltage transformer by switching transmission, separated and after the class returned by sampling the voltage from the opto-coupler pass separated after class, so before the mains voltage, and after the classseparation, which is called cold plate, it is safe, transformers before power is independent, which is called switching power supply.the DC / DC conversionDC / DC converter is a fixed DC voltage transformation into a variable DC voltage, also known as the DC chopper. There are two ways of working chopper, one Ts constant pulse width modulation mode, change the ton (General), the second is the frequency modulation, the same ton to change the Ts, (easy to produce interference). Circuit by the following categories:Buck circuit - the step-down chopper, the average output voltage U0 is less than the input voltage Ui, the same polarity.Boost Circuit - step-up chopper, the average output voltage switching power supply schematic U0 is greater than the input voltage Ui, the same polarity.Buck-Boost circuit - buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, the inductance transmission.Cuk circuit - a buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, capacitance transmission.The above-mentioned non-isolated circuit, the isolation circuit forward circuits, feedback circuit, the half-bridge circuit, the full bridge circuit, push-pull circuit. Today's soft-switching technology makes a qualitative leap in the DC / DC the U.S. VICOR company design and manufacture a variety of ECI soft-switching DC / DC converter, the maximum output power 300W, 600W, 800W, etc., the corresponding power density (6.2 , 10,17) W/cm3 efficiency (80-90)%. A the Japanese Nemic Lambda latest using soft-switching technology, high frequency switching power supply module RM Series, its switching frequency (200 to 300) kHz, power density has reached 27W/cm3 with synchronous rectifier (MOSFETs instead of Schottky diodes ), so that the whole circuit efficiency by up to 90%.AC / DC conversionAC / DC conversion will transform AC to DC, the power flow can be bi-directional power flow by the power flow to load known as the "rectification", referred to as "active inverter power flow returned by the load power. AC / DC converter input 50/60Hz AC due must be rectified, filtered, so the volume is relatively large filter capacitor is essential, while experiencing safety standards (such as UL, CCEE, etc.) and EMC Directive restrictions (such as IEC, FCC, CSA) in the AC input side must be added to the EMC filter and use meets the safety standards of the components, thus limiting the miniaturization of the volume of AC / DC power, In addition, due to internal frequency, high voltage, current switching, making the problem difficult to solve EMC also high demands on the internal high-density mountingcircuit design, for the same reason, the high voltage, high current switch makes power supply loss increases, limiting the AC / DC converter modular process, and therefore must be used to power system optimal design method to make it work efficiency to reach a certain level of satisfaction.AC / DC conversion circuit wiring can be divided into half-wave circuit, full-wave circuit. Press the power phase can be divided into single-phase three-phase, multiphase. Can be divided into a quadrant, two quadrant, three quadrants, four-quadrant circuit work quadrant.he selection of the switching power supplySwitching power supply input on the anti-jamming performance, compared to its circuit structure characteristics (multi-level series), the input disturbances, such as surge voltage is difficult to pass on the stability of the output voltage of the technical indicators and linear power have greater advantages, the output voltage stability up to (0.5)%. Switching power supply module as an integrated power electronic devices should be selected。
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3.3网络应用和测试
在实际应用中,收集的样本数据为272个随机组合的常用的负载类型。首先将200个样品作为测试部分,其余的72个样本则用于评价。在测试过程中系统采用梯度最速下降法，其中：学习因子η= 0.0075，动量因子α= 0.085。经测试结果表明,均方误差为0.118348,相关系数为0.994。以上数据则表明网络识别满足实际应用需求。
2.2多功能电源控制柜
多功能电源控制柜是整个系统的核心部分。它不仅对多用户的电气参数进行实时测量，而且还对负荷具有自动识别，切断危险载荷故障，记录数据和定时等功能。为了便于系统维护，模块化设计部分的应用程序有三个部分构成：包括输入接口板部分，主控板部分和输出接口板部分。
2.2.1输入和输出接口板
输入接口部分有16个模拟信号输入通道。第一个通道为相电压信号输入通道,其余15个通道为负载用户当前的信号通道。每个阶段的15个通道的各相电压和电流信号分别转换为0 ~ 3.3 v的模拟信号，再通过变压器、运算放大器和滤波器电路送入主控板TMS320F2812 ADC模块，以满足TMS320F2812 ADC模块的单极性特性。交流零电平的输入信号提高至1.6 v作为高精度电源参考值。输出接口部分同பைடு நூலகம்5个用户通道的继电器连接在一起。基于负载识别结果信息反馈和管理人员的命令指示，TMS320F2812的输出端口可以直接驱动ULN2804来控制相应的继电器。
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是
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图1 多功能电源控制柜的软件流程图
5．结论
本文介绍了一种用于宿舍的智能电源管理DCS系统。基于长期的实际操作，它表明系统测量、控制准确，可靠且易于使用。目前系统的应用能够大大降低宿舍的火灾风险且能减轻管理人员的作业负担。此外，系统还实现了校园水、电和热的集中网络监控和控制并且影响着其在未来的发展和应用。
2012年国际研讨会上的信息与电子工程（IWIEE）
开发一种新型多功能电源管理DCS系统
摘要
本文介绍了一个为宿舍火灾应急处理提供的双层网络智能电源管理DCS系统。本课题设计采用基于ARM Cortex -M3的LM3S8962微处理器，它很容易完成以太网和RS485总线的直接互连。软件设计部分建立在μC/OS-II嵌入式实时操作系统平台。为了提高多用户电参数的实时测量精度，底层的电源控制使用 TMS320F2812 DSP对数据进行采样和实时处理。由于电网存在频率漂移,系统对交流电源采用锁相技术来产生同步的多个频率脉冲。所以整周期采样措施可以完全实现。该系统采用小波神经网络技术来解决本课题复杂的载荷识别问题，从而达到大大降低宿舍火灾的风险的目的，并且减轻了管理人员的负担。经长期的实际运行，结果表明该系统测量准确、控制方便，可靠且易于使用。
1．介绍
在学生宿舍用电安全是非常重要的事情。随着电力设备的实时更新和多元化的发展与应用，为大学生提供一个更加安全、舒适的生活环境是一个时刻需要考虑的问题。目前，一些高校采用IC卡技术，实现了自动功率测量和公寓管理。但是，由于IC卡技术不具备负载识别功能，也无法从根本上消除用电安全隐患。因此，需要开发一个综合载荷识别、测量，和控制的公寓用电管理系统。
该系统开发过程中应用了通信技术、微电子技术和模式识别技术，同时系统也集成了多用户的网络监控和电源管理功能，能够自动识别负载类型和对其实施控制，此外系统还具有配额情报反馈、信用预警、高风险的负载切断、文档存储和定时功能。
2.硬件电路设计
本系统是一个两层网络的分布式控制系统，其中包括：管理计算机，RS485-以太网网关和多功能电源控制柜。管理员可以有效地通过WEB页面监控每个学生宿舍的用电情况。收集的数据从电源控制柜通过RS485总线传输到网关。
3.非线性负载识别
3.1负载特征提取
宿舍内用电设备通常分为线性和非线性两类负载。对于线性负载的电流和电压波形基本上是相同的。但对于非线形负载部分往往内部有大容量的电容器，这就导致了每个周期强烈的冲击电流和平坦的顶电压波形。在目前的实际应用中，Dmeyer与5级小波分解应用于构造特征参数以对载荷进行识别。非线性负载以总能量、第五层能量的细节部分、第五层总体与细节的能量比率为特征。
6．致谢
该研究项目的财政支持源于河北省教育厅（批准号NO.2010273）的科研计划。在整个研究中也得到了很多人士的支持。我们在此感谢DSP实验室中的所有成员，感谢他们为我们提供的实验设备和仪器。同时我们也表达我们心中的关爱和感激之情，我们亲爱的家人，感谢你们无尽的理解和支持。
7.参考文献
[1]刘锴.ARM嵌入式应用技术基础[M].清华大学出版社2009年，第100-120页（中国）
3.2神经网络模型设计
由于功率和非线性负载，所提取的特征参数之间存在着复杂的非线性映射的三层BP网络应用。电源电压，负载总功率，负载电流小波分解后的细节部分，第五级能源的总能量以及一般的和详细的第五级之间的能量比例作为特征参数的神经网络输入。非线性负载功率作为神经网络的输出。由于没有确定隐层节点数，本研究中的理论指导，隐藏节点被选为节点6。S型函数用于输入层与隐含层之间，而purelin函数则用于隐层到输出层。
2.1嵌入式网关
嵌入式网关选用LuminaryMicro公司的LM3S8962控制芯片。LM3S8962微处理器基于ARM Cortex -M3[1]。这是一个具有32位处理性能的RISC，工作频率能够高达50MHz，处理能力为1.25DMIPS/MHz。LM3S8962自开发以来已经集成了10/100以太网和两个完全可编程的16C550型UART，可以根据需求对外扩展添加一个RS485总线驱动器，网络隔离变压器和一些相关辅助硬件设备。隔离变压器HR601680network设计和生产地在Han Ren。为了保存网关设置的重要参数和控制柜的相关重要信息指标，该系统还配备了一个32K的非易失性铁电存储器FM24CL256。
4．软件设计
本系统软件由管理平台、嵌入式网关和多功能电力控制柜组成。管理平台软件基于B / S架构。它能够实现实时监控，并且具有图形显示，自动统计，数据存储，管理报告，目标比较和数据上传等功能。嵌入式网关软件建立在μC/OS-II嵌入式实时操作系统平台之上。它有四个模块：主程序模块、RS485通讯模块、以太网通讯模块和协议转换模块。其中主程序模块将兼顾系统初始化、任务创建和调度功能。RS485总线通信模块主要用来完成数据的初始化，接收和传输，以太网通信模块控制，以太网数据的接收和发送等功能。控制柜是基于模块化的软件架构设计，包括电气参数计算，电力计费，载荷识别，异常处理和电力通信网关等部分。下图所示为多功能电源控制柜的软件流程图。
2.2.2主控制板
主控制板电路采用由德州仪器公司生产的TMS320F2812的高速数字信号处理芯片。TMS320F2812的CPU时钟频率高达150MHz。该芯片包含16个通道，12位A / D且A / D转换时间小于100ns。
任何交流电源都存在频率漂移现象。如果内部定时器TMS320F2812每次A / D转换起始值被设置为20/N毫秒，其中N是采样点的一个周期，取值为128，另外，采样周期与电源工作频率不可能完全同步，并且整个周期可能会引起非采样测量误差，为了解决这一问题，本系统采用特殊的数字锁相芯片CD404612和二进制计数器CD4040构成的锁相电路。CD4046输出引脚的多个频率脉冲将被用来作为同步脉冲信号，每次启动A / D转换，以此可以实现精确的信号采样间值。
日历时钟芯片PCF8583通过I2C总线的应用以此来提供秒、分、小时、日、周、月和年的此类信息。断电故障和过载信息将被存储在非易失性EEPROM芯片24LC256中，并进一步通过网络送入SCITMS320F2812芯片模块。此外，本系统还配备有备用电池和断电延时关断电路，以便在断电的情况下，以确保数据的安全性和可靠性。