外文翻译-EDA的发展及VHDL的应用

0外文资料ThedevelopmentofEDAandtheapplicationofVHDL90sin20centuries,internationallastelectronicsandcalculatortechniquemoretheforerunnersnation,hasbeenbeingactivelyinvestigatinganewdesignmethodoftheelectronicselectriccircuit,andcarriedonanexhaustivechangeintheaspectsofdesigningamethod,toolwait,obtainhugesuccess.Atthedesignrealmoftheelectronicstechnique,theapplicationofprogrammablelogicsparepart(likeCPLD,FPGA),havealreadygotextensiveuniversality,thesesparepartsbroughttremendousvividforthedesignofnumericalsystem.ThesesparepartscanpassasoftwareplaitadistancebutastoitshardwarestructureandworkthewaycarryonheavyGouandmakethusthedesignofhardwarecanlikesoftwaredesignsoconvenientfast.Theallthesebiggestchangedatraditionalnumericalmethod,designprocessofthesystemdesignanddesignideaandpromotedtheEDAtechnicalquickdevelopment.TheEDAisanelectronicsdesignautomationofabbreviation,designfromthecalculatorassistanceatthebeginningof90sin20centuries,calculatorassistancemanufacturing,calculatorassistancetestandcalculatorlendsupporttotheconceptofengineeringadevelopmentsincethen.TheEDAtechniqueistotakecalculatorastool,designatEDAsoftwareterraceup,usethehardwaredescriptionlanguageHDLcompletionadesignadocument,thenisofoneselfcompletedlogictoeditandtranslate,turnChien,partitionedbythecalculator,comprehensive,excellentturn,setup,clothlinewithimitatereally,untilforparticulartargetchipofpropergotogetherwithtoeditandtranslate,thelogicreflecttoshootwithplaitdistancedownloadetc.work.TheEDAtechnicalemergence,biggestraisedefficiencyandmaneuverabilityofelectriccircuitdesign,easedtodesignoflaborstrength.ThesesparepartscanpassasoftwareplaitadistancebutastoitshardwarestructureandworkthewaycarryonheavyGouandmakethusthedesignofhardwarecanlikesoftwaredesignsoconvenientfast.Theallthesebiggestchangedatraditionalnumericalmethod,designprocessofthesystemdesignanddesignideaandpromotedtheEDAtechnicalquickdevelopment.MakeuseofEDAtool,theelectronicsdesignercanstartdesignelectronicssystemfromtheconcept,calculateway,agreement.etc.,agreatdealofworkcanpasscalculatorcompletion,andcandesigntheelectronicsproductisfromtheelectriccircuit,thefunctionanalyze1computeofthewholeprocessofdesignanIClandscapeorPCBlandscapeonboardautoprocessingcompletion.UsetotheEDAconceptorcategoryverybreadthnow.Includeineachrealmofthemachine,electronics,correspondence,aviationaerospace,chemicalengineering,mineral,livingcreature,medicalscience,military.etc.,allthereisEDAapplication.TheEDAtechniquehasalreadyextensivelyusedineacharchdukedepartment,theQibusinessunitandresearchteachingsectioncurrently.Forexampleintheairplanethemanufacturingtheprocess,fromdesign,performancetestandcharacteristicanalyticaluntilflyemulation,mayinvolveanEDAtechnique.TheEDAtechniquethatthistextpointmainlytothedesign,PCBdesignoftheelectronicselectriccircuitandICdesign.TheEDAdesigncanisdividedintosystemclass,electriccircuitclassandphysicstocarryoutclass.TheEDAincommonusesoftwareandtoolpileuponeafteranotherandgetintoanourcountrycurrentlyandhavetheEDAsoftwareofextensiveinfluencetohave:MultiSIM7(thelatesteditionoforiginalEWB),PSPICE,OrCAD,PCAD,Protel,Viewlogic,Mentor,Graphics,Synopsys,LSIIogic,Cadence,MicroSim,ISE,modelsimetc.Thesetoolsallhavestrongerfunction,generallycanusedforafewaspects,forexamplealotofsoftwaresallcancarryonanelectriccircuitdesignwithimitatereally,togetherenteringcanalsocarryonPCBtoautomaticallysetupclothline,canoutputvariousnetformadocumentwiththethirdsquaresoftwareconnect.TheVHDLbirthin1982.Attheendof1987,theVHDLisconfirmbyIEEEandAmericanMinistryofNationalDefensetodescribelanguageforthestandardhardware.AnnouncedVHDLstandardeditionfromtheIEEE,IEEE-1076(call87versions)after,theeachEDAcompanyreleasedownVHDLdesignenvironmentoneafteranother,ordeclaredthattheowndesigntoolcanconnectwithVHDL.HenceforththeVHDLdesignedrealmtogettoextensivelyacceptintheelectronics,andgraduallyreplacedanoriginallynot-standardhardwaredescriptionlanguage.In1993,theIEEEcarriedontorevisetotheVHDL,describeabilitytoupexpandaVHDLcontentsfromhigherabstractlayerandthesystem,announcedtheVHDLofnewedition.VHDLandVerilogaretheindustrialstandardhardwaredescriptionoftheIEEEslanguage,againarrivesupportofnumerousEDAcompanies,atelectronicsengineeringrealm,havebecomeingeneralusehardwaretodescribelanguageinfact.Thereisexpertthink,inthenewcenturyin,theVHDLwillstarttoundertakeagreatlypartofnumericalsystemdesignmissionattheVeriloglanguage.TheVHDLlanguageisakindofdeluxelanguagewhichusedsforanelectriccircuit2design.Itexpectstoappearafterthe80sof.BEatthebeginningcomeoutbyAmericanMinistryofNationalDefensedevelopmenttoprovidetheAmericansoliderwiththecredibilitywhichusestoraiseadesignwithcut1kindofdevelopmentperiodtousethescopesmallerdesignlanguage.VHDL,Translatingintochineseissoonextremelyhighthedescriptionlanguageoftheintegratedcircuithardware.Soitoftheapplicationmainlyisanapplicationinthedesignofnumericalelectriccircuit.Currently,itisintheapplicationmostinchinaisthedesignwhichusesintheFPGA/CPLD/EPLD.Certainlyinsomeunitswithstrongerrealstrenght,itisalsousetodesignASIC.TheVHDLmainlyusedsforthestructure,behaviorwhichdescribesnumericalsystem,functionwithconnect.Inadditiontoimplyingmanylanguagessentencewhichhaveahardwarecharacteristic,VHDLlanguagesformsanddescriptionstyleandsentenceconstructionareverysimilaratgeneralcalculatordeluxelanguage.VHDLprocedurestructurecharacteristicsisanengineeringdesign,orcallthatthedesignentity(canbeacomponent,anelectriccircuitmoldpieceorasystem)isdividedintoexterior(orcallbutpart,andport)withinnerpart(orcalltocantseepart),sinceinvolveinternalfunctionandcalculatewayofentitytocompletepartof.Atto1designedentitytodefineexteriorinterfaceafter,onceitinternaldevelopmentcompletionafter,otherdesignscandirectlyadjusttousethisentity.ThiskindofwilldesignentitytobedividedintoalittlebitbasicVHDLsystemthatisaVHDLsysteminsidetheconceptofoutsidepartdesigndesignofalittlebitbasicandotherhardwaredescribethelanguagecompareandtheVHDLhasafollowingcharacteristics:Thefunctionisstrongandthedesignbevivid.TheVHDLhasthefunctionstronglanguagestructure,candescribeacomplicatedlogiccontrolwiththesimpleanddirectandexplicitsourcecode.Ithasamulti-layerdesigndescriptionfunction,inmultiplelayersthinturn,finallydirectlybornelectriccircuitclassdescription.TheVHDLsupportssynchronouselectriccircuit,differencestreadelectriccircuitwithrandomthedesignofelectriccircuit,thisbetheotherhardwaredescriptionalthoughthelanguagecantcompareto.TheVHDLstillsupportsvariousdesignmethod,sincesupportfromthebottomupwarddesign,supportagainfromthedesignofcrestdeclivity;Sincethesupportmoldpieceturnsadesign,supportlayersturnadesignagain.Supportextensivelyandbeeasytoamodification.BecausetheVHDLhasalreadybecomeIEEEstandardthenormofhardwaredescriptionlanguage,mostEDAtoolsalmostsupportVHDLcurrently,thisisVHDLoffurtherexpansionwithextensivelyappliedlayfoundation.Inthedesign3processofthehardwareelectriccircuit,themaindesigndocumentisthesourcecodewhichwriteswiththeVHDL,theVHDLeasilyreadswiththestructureturn,sobeeasytoamodificationdesign.Thestrongsystemhardwaredescribesability.TheVHDLhasamulti-layerdesigndescriptionfunction,sincecandescribesystemclasselectriccircuit,candescribedoorclasselectriccircuitagain.Anddescriptionsincecanadoptabehaviordescription,depositamachinetodeliverdescriptionorstructuredescription,canalsoadoptthehybriddescriptionofthreesmixture.Moreover,VHDLsupportisinertialtodelayanddelivertodelay,canalsoaccuratelybuilduphardwareelectriccircuitmodel.VHDLsupportpreparedefiniteofwithfromdefinitionofdatatype,bringhardwaredescriptionabiggerfreedomdegree,makedesignthepersonnelcanexpedientlyestablishthesystemmodelofhightime.Theindependenceisatthedesignofsparepart,havenothingtodowiththecraft.DontneedtoconsiderachoicecompletionthesparepartofdesignfirstwhiledesigningapersonneltocarryonadesignwiththeVHDL,canconcentrateenergytocarryondesignofexcellentturn.Whenthedesigndescriptioncompleteafter,cancarryoutitsfunctionwithvariousdifferentsparepartstructure.Verystrongtransplantationability.TheVHDLisakindofhardwaredescriptionforstandardizelanguage,thesameofdesigndescriptioncanbesupportbythedifferenttoolandmaketodesigntodescribeofthetransplantationmakepossible.Beeasytoashareandreplytouse.TheVHDLadoptioncanbuildupvariousmoldpiecethatcanagainmakeuseofaccordingtothedesignmethodofdatabase.Thesecannedinadvancedesignorusetodesignamediumbackupmoldapiecebeforeanddeposittedthesetothedatabasein,canbeinlaterlyofthedesigncarryonreplyingtouse,canmakethedesignresultbedesignthepersonnelstocarryonexchangesandshare,paredwithotherhardwaredescriptionlanguages,theVHDLhavestrongerbehaviordescriptionability,cometoadecisionhimtobecomeasystemdesignrealmthebesthardwareadescriptionlanguagethus.Thestrongbehaviordescriptionabilityistoavertfromconcretesparepartstructureanddescribeanddesignimportantassuranceoflarge-scaleelectronicssystemfromthelogicbehavior.theVHDLbeabundantofimitatetruelanguagesentenceanddatabasefunction,makeinanybigsystemofthedesigncaninspectafunctionpossibilityofdesignthesysteminearlydays,cancarryonimitatingtrueemulationtothedesignatanytime.theabilityandprocedurestructureofthebehaviordescriptionwithlexical4VHDLcometoadecisionthedecompositionthathehastosupportalarge-scaledesignwithhavealreadyhavedesignofagainmakeuseoffunction.Meetthemarketdemandinglarge-scalesystemefficiently,thecompletionofthehighspeedhastoincludemanypeopletheseveralgenerationhairseteventogetherandabreastworksandthencancarryout.forusethedesignofanassuranceofVHDLcompletion,canmakeuseofEDAtooltocarryonlogiccomprehensivewithexcellentturn,andautooftheVHDLdescribethedesignchangeintothedoorclassnetform.thedescriptionofVHDLtodesignhaveoppositeandindependent,thedesigncannotunderstandthestructureofhardwareandneednotmanagethetargetsparepartthattheenddesigncarryout,eitheriswhat,butcarryonanindependentdesign.51中文译文EDA的发展及VHDL的应用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，而且取得了巨大成功。在电子技术设计领域，可编程逻辑器件（如CPLD、FPGA）的应用，已得到广泛的普及，这些器件为数字系统的设计带来了极大的灵活性。这些器件可以通过软件编程而对其硬件结构和工作方式进行重构，从而使得硬件的设计可以如同软件设计那样方便快捷。这一切极大地改变了传统的数字系统设计方法、设计过程和设计观念，促进了EDA技术的迅速发展。EDA是电子设计自动化的缩写，在20世纪90年代初从计算机辅助设计、计算机辅助制造、计算机辅助测试和计算机辅助工程的概念发展而来的。EDA技术就是以计算机为工具，设计者在EDA软件平台上，用硬件描述语言HDL完成设计文件，然后由计算机自动地完成逻辑编译、化简、分割、综合、优化、布局、布线和仿真，直至对于特定目标芯片的适配编译、逻辑映射和编程下载等工作。EDA技术的出现，极大地提高了电路设计的效率和可操作性，减轻了设计者的劳动强度。利用EDA工具，电子设计师可以从概念、算法、协议等开始设计电子系统，大量工作可以通过计算机完成，并可以将电子产品从电路设计、性能分析到设计出IC版图或PCB版图的整个过程的计算机上自动处理完成。现在对EDA的概念或范畴用得很宽。包括在机械、电子、通信、航空航天、化工、矿产、生物、医学、军事等各个领域，都有EDA的应用。目前EDA技术已在各大公司、企事业单位和科研教学部门广泛使用。例如在飞机制造过程中，从设计、性能测试及特性分析直到飞行模拟，都可能涉及到EDA技术。本文所指的EDA技术，主要针对电子电路设计、PCB设计和IC设计。EDA设计可分为系统级、电路级和物理实现级。EDA常用软件、工具层出不穷，目前进入我国并具有广泛影响的EDA软件有：multiSIM7(原EWB的最新版本)、PSPICE、OrCAD、PCAD、Protel、Viewlogic、Mentor、Graphics、Synopsys、LSIIogic、Cadence、MicroSim，ISE，modelsim等等。这些工具都有较强的功能，一般可用于几个方面，例如很多软件都可以进行电路设计与仿真，同进还可以进行PCB自动布局布线，可输出多种网表文件与第三方软件接口。VHDL诞生于1982年,1987年底VHDL被IEEE和美国国防部确认为标准硬0件描述语言。自IEEE公布了VHDL的标准版本，各EDA公司相继推出了自己的VHDL设计环境，或宣布自己的设计工具可以和VHDL接口。此后VHDL在电子设计领域得到了广泛的接受，并逐步取代了原有的非标准的硬件描述语言。1993年，IEEE对VHDL进行了修订，从更高的抽象层次和系统描述能力上扩展VHDL的内容，公布了新版本的VHDL。现在，VHDL和Verilog作为IEEE的工业标准硬件描述语言，又得到众多EDA公司的支持，在电子工程领域，已成为事实上的通用硬件描述语言。有专家认为，在新的世纪中，VHDL于Verilog语言将承担起大部分的数字系统设计任务。VHDL语言是一种用于电路设计的高级语言。它在80年代的后期出现。最初是由美国国防部开发出来供美军用来提高设计的可靠性和缩减开发周期的一种使用范围较小的设计语言。VHDL翻译成中文就是超高速集成电路硬件描述语言。因此它的应用主要是应用在数字电路的设计中。目前，它在中国的应用多数是用在FPGA/CPLD/EPLD的设计中。当然在一些实力较为雄厚的单位，它也被用来设计ASIC。VHDL主要用于描述数字系统的结构，功能和接口。除了含有许多具有硬件特征的语句外，VHDL的语言形式和描述风格与句法是十分类似于一般的计算机高级语言。VHDL的程序结构特点是将一项工程设计，或称设计实体（可以是一个元件，一个电路模块或一个系统）分成外部（或称可视部分,及端口)和内