Concept
ThetaskofcomputercompositionistostudytheinternalstructureandinterconnectionofeachcomponentaftertheinstructionsetsystemstructuredeterminesthefunctionandconceptualstructureassignedtothehardwaresystemtorealizethemachineVariousfunctionsandfeaturesoftheinstructionset.Thisconnectionincludestheinternalandinteractionofvariousfunctionalcomponents.
Theproblemtobesolvedbycomputercompositionishowtobestandmostreasonablycomposeeachdeviceandcomponentintoacomputerunderthedesiredperformanceandprice,sothatthedeterminedISAhasbeenrealized.Theaspectstobedeterminedinthecomputercompositiondesignshouldinclude:
(1)Datapathwidth:thenumberofbitsofinformationtransmittedinparallelonthedatabusatatime.
(2)Thesettingofspecialparts:whethertosetspecialpartssuchasmultiplicationanddivision,floatingpointcalculation,characterprocessing,addresscalculation,etc.,thenumberofsettingsandthespeed,priceandfrequencyofuseofspecialpartstobeachievedbythemachineDegreeandsoon.
(3)Thedegreeofsharingofcomponentsinvariousoperations:time-sharingishighlyused,althoughitlimitsthespeed,butthepriceischeap.Settingupmorecomponentsreducesthedegreeofsharing,andbecausetheparallelismofoperationsincreases,thespeedcanbeincreased,butthepricewillalsoincrease.
(4)Parallelismoffunctionalcomponents:whethertousesequentialserial,oroverlap,pipelineordistributedcontrolandprocessing.
(5)Thecompositionmethodofthecontrolmechanism:whetheritiscontrolledbyhardlinkormicroprogram,whetheritissingle-machineprocessingormulti-machineorfunctiondistributedprocessing.
(6)Bufferingandqueuingtechnology:Howtosetupandhowlargeabufferissetbetweencomponentstocoordinatetheirspeeddifference;userandom,first-in-first-out,first-in-last-out,priority,orcircularmodeToarrangetheorderofeventprocessing.
(7)Predictiveandpredictivetechnology:Whatprinciplesshouldbeusedtopredictfuturebehaviorforoptimizingperformance.
(8)Reliabilitytechnology:Whatredundancyandfaulttolerancetechnologyisusedtoimprovereliability.
Hardwarecomponents
Mainlydividedintofiveparts:
1.Controller(Control):thecentralnerveoftheentirecomputer,itsfunctionisInterpretthecontrolinformationspecifiedbytheprogram,controlaccordingtoitsrequirements,scheduleprograms,data,andaddresses,coordinatetheworkofvariouspartsofthecomputer,andaccesstomemoryandperipherals.
2.Datapath:Thefunctionofthearithmeticunitistoperformvariousarithmeticandlogicaloperationsonthedata,thatis,toprocessthedata.
3.Memory:Thefunctionofmemoryistostoreprograms,data,varioussignals,commandsandotherinformation,andprovidethisinformationwhenneeded.
4.Input(Inputsystem):Theinputdeviceisanimportantpartofthecomputer.Theinputdeviceandtheoutputdevicearecollectivelycalledexternaldevices,orperipheralsforshort.Informationsuchastext,characters,controlcommands,ordatacollectedonsiteareinputtothecomputer.Commoninputdevicesincludekeyboards,mice,photoelectricinputmachines,tapedrives,diskdrives,opticaldiscdrives,andsoon.
5.Output(Outputsystem):Theoutputdeviceisalsoanimportantpartofthecomputerastheinputdevice.Informationsuchascontrolsignalsisoutput.Commonlyusedoutputdevicesformicrocomputersincludedisplayterminals,CRTs,printers,laserprinters,plotters,tapes,andCD-ROMs.
(cpu=controller+arithmeticunit
Motherboard=I/Obus,inputandoutputsystem
memory=memory+harddisk
I/Oequipment:keyboard,mouse,scanner,monitor,etc.mouse,scannerdigitizer,cardreader,papertape...)
software
softwareOverview
ComputerSoftware(ComputerSoftware)referstotheprogramsanddocumentsinthecomputersystem.Theprogramisthedescriptionoftheprocessingobjectandprocessingrulesofthecomputingtask;thedocumentistheexplanatoryinformationneededtofacilitatetheunderstandingoftheprogram.Theprogrammustbeloadedintothemachinetowork,andthedocumentisgenerallyforpeopletosee,notnecessarilyloadedintothemachine.Thesoftwareistheinterfacebetweentheuserandthehardware.Userscommunicatewithcomputersmainlythroughsoftware.Softwareisanimportantbasisforcomputersystemdesign.Fortheconvenienceofusers,inordertomakethecomputersystemhaveahigheroverallutility,whendesigningthecomputersystem,wemustconsiderthecombinationofsoftwareandhardware,aswellasuserrequirementsandsoftwarerequirements.Thecorrectmeaningofsoftwareshouldbe:(1)Whenitisrunning,itcanprovideinstructionsorcomputerprogramcollectionsthatprovidetherequiredfunctionsandperformance.(2)Theprogramcanhandlethedatastructureoftheinformationsatisfactorily.(3)Documentsrequiredtodescribethefunctionalrequirementsoftheprogramandhowtooperateandusetheprogram.Softwarehasdifferentcharacteristicsfromhardware:(1)Differentformsofexpression,hardwareistangible,colored,smelly,visible,tangible,andsmellable.Thesoftwareisinvisible,colorless,tasteless,invisible,untouchable,andunsmelling.Softwareismostlystoredinpeople'sheadsoronpaper.Whetheritiscorrectornot,whetheritisgoodorbad,can'tbeknownuntiltheprogramisrunningonthemachine.Thisbringsmanydifficultiestodesign,productionandmanagement.(2)Differentproductionmethods.Softwareisdevelopment,whichisthehighlevelofhumanintelligence,nothardwaremanufacturinginthetraditionalsense.Althoughtherearemanysimilaritiesbetweensoftwaredevelopmentandhardwaremanufacturing,thetwoactivitiesarefundamentallydifferent.(3)Differenthardwareproductsarerequiredtoallowerrors,butsoftwareproductsarenotallowedtohaveerrors.(4)Maintainingdifferenthardwarerequiresoldandworn-out.Intheory,softwarewillnotbeworn-out,butinpractice,softwarewillalsobecomeoldanddeteriorated.Becauseintheentirelifeofthesoftware,ithasbeeninastateofchangeandmaintenance.
Computersoftwareisdividedintosystemsoftwareandapplicationsoftware.Ifthecomputeriscomparedtoaperson,thenthehardwarerepresentsthehumanbody.Thesoftwarerepresentsthehumanmindandsoul.Acomputerwithoutanysoftwareiscalled"baremetal".
Systemsoftware
Systemsoftwarereferstoasystemthatcontrolsandcoordinatescomputersandexternaldevices,supportsthedevelopmentandoperationofapplicationsoftware,andisacollectionofvariousprogramswithoutuserintervention.ThemainfunctionsItisthescheduling,monitoringandmaintenanceofcomputersystems;responsibleforthemanagementofvariousindependenthardwareinthecomputersystemsothattheycancoordinatetheirwork.Systemsoftwareallowscomputerusersandothersoftwaretotreatthecomputerasawholewithouthavingtotakeintoaccounthowtheunderlyinghardwareworks.(OperatingsystemssuchasWindows,Linux,Dos,Unix,etc.areallsystemsoftware.)
Applicationsoftware
Applicationsoftwareisavarietyofprogramminglanguages​​thatuserscanuse,Andacollectionofapplicationprogramscompiledinvariousprogramminglanguages,dividedintoapplicationsoftwarepackagesanduserprograms.Anapplicationsoftwarepackageisacollectionofprogramsdesignedtosolveacertaintypeofproblembyusingacomputerforusebymultipleusers.Computersoftwareisdividedintotwocategories:systemsoftwareandapplicationsoftware.Applicationsoftwareisthepartofsoftwarethatisprovidedtomeettheapplicationneedsofusersindifferentfieldsanddifferentproblems.Itcanbroadentheapplicationfieldsofcomputersystemsandamplifythefunctionsofhardware.(Forexample,Word,Excel,QQ,etc.areallapplicationsoftware)