英文翻译等精度频率计Word文档格式.docx
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英文翻译等精度频率计Word文档格式.docx
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AndotherprecisionmeasuringfrequencyPrinciple
Frequencymeasurementmethodscanbedividedintotwokinds:
(1)directmeasurementmethod,thatis,atacertaintimemeasurementgatemeasuredpulsesignalnumber.
(2)indirectmeasurements,suchasthecyclefrequencymeasurement,VFconversionlaw.FrequencyMeasurementindirectmeasurementmethodappliesonlytolow-frequencysignals.
Basedontheprinciplesoftraditionalfrequencymeasurementofthefrequencyofmeasurementaccuracywillbemeasuredwiththedeclineinsignalfrequencydecreasesinthemorepracticallimitations,suchastheaccuracyandfrequencyofmeasurementnotonlyhashighaccuracy,butalsointhewholefrequencyregiontomaintainconstanttestaccuracy.ThemainmethodofmeasurementfrequencymeasurementPreferencesgatedsignalGATEissuedbytheMCU,GATEtimewidthonthefrequencymeasurementaccuracyoflessimpact,inthelargercontextofchoice,aslongastheFPGAin32of100inthecounterbMSignalsarenotoverflowline,inaccordancewiththetheoreticalcalculationGATEtimecanbegreaterthanthewidthTc42.94s,butduetothesingle-chipmicrocomputerdataprocessingcapacityconstraints,theactualwidthoflesstime,generallyintherangeofbetween0.1schoice,thatis,high-frequency,shortergate;
lowgatelonger.ThistimegatewidthTcbasedonthesizeofthemeasuredfrequencyautomaticallyadjustfrequencymeasurementinordertoachievetheautomaticconversionrange,andexpandedtherangeoffrequencymeasurement;
realizationoftheentirescopeofmeasurementaccuracy,reducethelow-frequencymeasurementerror.
ThedesignofthemainmethodsofmeasuringthefrequencymeasurementandcontrolblockdiagramasshowninFigure1.Figure1PreferencesgatedsignalGATEissuedbytheMCU,GATEtimewidthoflessfrequencymeasurementaccuracy,inthelargercontextofchoice,aslongastheFPGAin32of100inthecounterbMsignalOverflowwilldo,accordingtotheoreticalcalculationsGATEtimewidthTccanbegreaterthan42194s,butduetothesingle-chipmicrocomputerdataprocessingcapacityconstraints,theactualwidthoflesstime,generally10to011sintheinter-choice,thatis,high-band,thegatetimeshorter,lowgatelonger.ThistimegatewidthbasedonthemeasuredTcautomaticallyadjustthesizeoffrequencymeasurementfrequencyrangetoachievetheautomaticconversion,andexpandedtherangeoffrequencymeasurement;
Frequencyofachieving
FrequencyMeasurementaccuracyofsuchmethod.Canbesimplifiedasshowninthediagram.MapCNT1andCNT2twocontrollablecounter,standardfrequency(f)signalfromtheCNF1clockinputcIKinput,thesignalmeasuredaftertheplastic(f)CNT2clockinputcIKinput.EachcounterintheCENinputasenableend,usedtocontrolthecountercount.WhenthegatesignalisHIGHPreferences(Preferencesstarttime).SignalmeasuredbytherisingedgeoftheDflip-flopinput,launchedatthesametimewithtwocountsofjuice;
Similarly,whenpreferencesforlowgatesignal(theendofPreferencestime),therisingedgeofthemeasuredsignalsthroughDTriggeroutputendofthecountertostopcounting.
Andthemedianfrequencyofrelevantindicators
Median:
Atthesametimethefiguresshowthatuptothemedian.Theusualeight-countfrequencyofonlyseveralhundredyuancanbuy.Forhighprecisionmeasurements,ninejustbeginning,themiddleis11,13canberelativelyhigh.
Overflowof:
-theabilitytopromoteitselftooverflowtheequivalentofthetotal.Someofthefrequencywithoverflowfunction,whichisthehighestoverflowdoesnotdisplayonlyshowsthatthebitbehind,inordertoachievethepurposeofthemedian.Hereistheestimatedvalueofindividualindicators.
Speed:
namely,thenumberofpersecond.Withthehighnumberofmeasurementparticularlyslowbutalsoloseitssignificance.Countingoftheusualeightfrequencymeasurement10MHzsignals,onesecondgatewillbe10000000Hz,whichisactuallyseven(equivalenttothemediannumberofcommonadmissionafterthevalue),toobtaineightneeded10secondsgate;
toobtainnineneeded100secondsgate,followedbyanalogy,showsthateventhepermissionof11need10,000secondmeasurementtime.Butinanycase,orsevenpersecond.Therefore,tofastmustbeafewhighspeed.
Distinction:
itislikeaminimumvoltagemetercantellhowmuchvoltageindicatorsaresimilar,thesmallerthebetter,unitps(picoseconds).1000ps=1ns.Supposeyouusethefrequencyof1nstodifferentiatebetweenane-12error,weneedans/1e-12=1000seconds.Alsoassumethatyouhaveafrequencyresolutionof100ps,themeasurementtimecanbeshortenedby10timesfor100seconds,orcanbeinthesame1000secondmeasuredunderane-14Error.
TimeandFrequencyMeasurement
Comparedtotraditionalmethodsofcircuitdesign,EDAtechnologyusesVHDLlanguagetodescribecircuitsystem,includingcircuitstructure,behavior,functionandinterfacelogic.VerilogHDLdescriptionofamulti-levelsystemhardwarefunctions,andsupporttop-downdesignfeatures.Designerscannotunderstandthehardwarestructure.Startfromthesystemdesign,onthetopfloorofasystemblockdiagramofthestructureanddesign,inadiagramwithVer-ilogHDLactsonthecircuitdescriptionandsimulationanderrorcorrection,andthenthesystemlevelverification,andfinallyuselogicsynthesisoptimizationtooltocreatespecificgate-levellogiccircuitnetlist,downloadtothespecificFPGAdevicetoinordertoachieveFPGAdesign.
Timeandfrequencymeasurementisanimportantareaofelectronicmeasurement.Frequencyandtimemeasurementhasbeenreceivingincreasingattention,length,voltage,andotherparameterscanbetransformedintoafrequencymeasurementandrelatedtechnologiestodetermine.Basedonthemoretraditionalmethodofsynchronizationcycle,andhasproposedamulti-cyclesynchronizationandquantitativemethodofmeasuringdelayfrequencymethod.
Themostsimplemethodofmeasuringthefrequencyofdirectfrequencymeasurementmethod.DirectFrequencyMeasurementisscheduledtoenterthegatesignalpulse,theadoptionofthenecessarycountingcircuit,thenumberofpulsesarefilledtocalculatethefrequencyoranalytesignalcycle.Inthedirectfrequencymeasurementonthebasisofthedevelopmentofmulti-cyclesynchronousmeasurementmethod,inthecurrentfrequencymonitoringsystemtobemorewidelyused.Multi-cyclesynchronizationfrequencymeasurementtechnologyactualgatetimeisnotfixedvalue,butthemeasuredsignalsinthewholecycletimes,andthemeasuredsignalsynchronization,therebyremovingthemeasuredsignalcountonwhentheword±
1error,measurementaccuracygreatlyimproved,andreachedintheentirespectrumofmeasurement,suchasprecisionmeasurement.
Inthetime-frequencymeasurementmethod,themulti-cyclesynchronizationisahighprecision,butstillunresolved±
aworderror,mainlybecauseoftheactualgateedgeandstandardfrequencysynchronizationisnotfillingpulseedgeTx=N0T0-△t2+△t1,ifaccuratelymeasuredshortintervalΔt1andΔt2,willbeabletoaccuratelymeasuretimeintervalsTx,eliminating±
awordcountingerror,soastofurtherenhanceaccuracy.
TomeasureashorttimeintervalΔt1andΔt2,commonlyusedanaloginterpolationmethodwiththecursorormorecombinedcyclesynchronization,althoughaccuracyisgreatlyimproved,buteventuallyfailedtoresolve±
aworderrorthisfundamentalissue,butthesemethodsequipmentcomplexandnotconducivetothepromotion.
Toobtainhighprecision,fastresponsetime,simplestructureandthefrequencyandtimemeasurementmethodisrelativelydifficult.
Judgingfromthestructureassimpleaspossibleatthesametimetakeintoaccountthepointofviewofaccuracy,multi-cyclesynchronizationanddelaybasedonthequantitativemethodsinashortperiodoftimeintervalmeasurement,achievedwithinthescopeofbroadband,suchashigh-resolutionmeasurementaccuracy.
QuantifiedbymeasuringshorttimeintervalsDelay
Photoelectricsignalcanbeinacertainstabilityinthemediumofrapidspread,andindifferentmediahavedifferentdel
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