电子大赛仪表篇数字万用表jhd12864c

LIMITPIN1Ground2PowerSupply3LCDDriveAdjust45H:READ;6EICselect7DATA8HDATA9LDATAStandardVDD--VVDDVLCDDriveVoltage--V--V--V-VLIMITPIN1Ground2PowerSupply3LCDDriveAdjust45H:READ;6EICselect7DATA8HDATA9LDATAStandardVDD--VVDDVLCDDriveVoltage--V--V--V-V0-VStandardSupplyVDD-0VLCDVDD-0VInput0VACCharacteristics(Vdd=5V±10%,Vss=0VMPUEEhighlevelElowlevelEriseEfailAddressholdDatadelay--ACCharacteristics(Vdd=5V±10%,Vss=0VMPUEEhighlevelElowlevelEriseEfailAddressholdDatadelayDataholdDatahold--DATADATADATADATADATASelectsignal1,HighSelectsignal2,HighResetsignal,low-LCDDrivenegativeBackLEDBackLEDMPUWriteMPUReadMPUWriteMPUReadI/OInputbuffercontrolsthestatusbetweentheenableanddisableofchip.UnlesstheCS1orCS2isinactivemode,inputoroutofdataandinstructiondonotexecute.ThereforeinternalstateisnotchangedButRSTBcanoperateregardlessofCS1andCS2.InputInputregisterisprovidedtointerfacewithMPUwhichisdifferentoperatingfrequency.InputregisterstoresthedatatemporarilybeforewritingitintodisplaydataRAM.WhenCS1orCS2isintheactivemode,R/WandRSselecttheinputregister.ThedatafromMPUiswrittenintoinputregisterandthenwriteitintodisplaydataRAM.DataislatchedwhenfallingoftheEsignalandwrittenautomaticallyintothedisplaydataRAMbyinternaloperation.OutputOutputregisterstoresthedatatemporarilyfromdisplaydataRAMwhenCS1orCS2isinactivemodeandR/WandRS=H.StoreddataindisplaydataRAMislatchedinoutputregister.WhenCS1orCS2isinactivemodeandR/W=H,RS=L,statusdata(busycheck)canbereadout.ToreadthecontentsofdisplaydataRAM,twiceaccessofreadinstructionisneeded.Infirstaccess,dataindisplaydataRAMislatchedintooutputregister.Insecondaccess,MPUcanreaddatawhichislatched.ThatistoreadthedataindisplaydataRAM,itneedsdummyread.Butstatusreaddoesnotneeddummy001Statusread(busy10Datawrite(frominputregistertodisplaydata1Dataread(fromtodisplaydataRAMtooutputSystemresetcanbeinitializedbysettingRSTBterminalatlowlevelSystemresetcanbeinitializedbysettingRSTBterminalatlowlevelwhenturningpoweron,instructionfromMPU.WhenRSTBbecomeslow,followingprocedureis-Display-Displaystartlineregisterbecomesetby0.(Z-addressWhileRSTBislowlevel,noinstructionexceptstatusreadcanbeaccepted.ResetstatusappearsadDB4.AfterDB4islow,anyinstructioncanbeaccepted.TheconditionsofpowersupplyatinitialpowerupareshownintableTable1.PowerSupplyInitialBusyBusyflagindicatesthatKS0108Bisoperatingornotoperating.WhenbusyflagisKS0108Bisinternaloperating.Whenbusyflagislow,KS0108Bcanacceptthedataorinstruction.DB7indicatesbusyflagoftheDisplayON/OFFFlip-Thedisplayon/offflip-flopmakeson/offtheliquidcrystaldisplay.Whenflop-flopisreset(logicallow).selectivevoltageornonselectivevoltageappearsonsegmentoutputterminals.Whenflip-flopisset(logicalhigh).nonselectivevoltageappearsonsegmentoutputterminalsregardlessofdisplayRAMdata.Thedisplayon/offflip-flopcanchangestatusbyinstruction.ThedisplaydataatallsegmentdisappearwhileRSTBislow.Thestatusoftheflop-flopisoutputtoDB5byreadXpageXpageregisterdesignatespageoftheinternaldisplaydataRAM.Ithasnotcountfunction.AnaddressissetbyYAddressResetRiseYaddresscounterdesignatesaddressoftheinternaldisplaydataRAM.Anaddressissetbyinstructionandisincreasedby1automaticallybyreadorwriteYaddresscounterdesignatesaddressoftheinternaldisplaydataRAM.Anaddressissetbyinstructionandisincreasedby1automaticallybyreadorwriteoperationsofdisplayDisplayDataDisplaydataRAMstoresadisplaydataforliquidcrystaldisplay.Toexpressonstateofdotmatrixofliquidcrystaldisplay.writedata1.Theotherway.offstatewritesDisplayStartLineThedisplaystartlineregisterindicatesaddressofdisplaydataRAMtodisplaytoplineofliquidcrystaldisplay.Bitdata(DB0:5)ofthedisplaystartlinesetinstructionsislatchedindisplaystartlineregister.ItisusedforscrollingoftheliquidcrystaldisplayDisplayControlThedisplaycontrolinstructionscontroltheinternalstateoftheKS0108B.InstructionisreceivedfromMPUtoKS0108Bforthedisplaycontrol.ThefollowingtableshowsvariousD000011111Controlsthedisplayonoroff.InternalstatusanddisplayRAMdataarenotaffected.SetSetPage000000011101Yaddress(0- SetstheYaddressintheYaddressSetstheXaddressattheXaddressIndicatesthedisplaydatadisplayedatthetopoftheStatus0100000Read 01:Inoperation 0:Display1:Display 01Giveaexample(Only*Ifmodulecan’tproducenegativevoltage,exteriorinputsnegativevoltagefromPIN(VO).Ifitcan,directlyusingorfixedresistancesuchasdrawing,thatmaynotGiveaexample(Only*Ifmodulecan’tproducenegativevoltage,exteriorinputsnegativevoltagefromPIN(VO).Ifitcan,directlyusingorfixedresistancesuchasdrawing,thatmaynot如有，则可如图直接用电位器或固定电阻，不考虑VEE。Programexample(Only#include<reg51.h>typedefunsignedchartypedefunsignedint ====WriteDisplay10WriteWritesdata(DB0:7)intodisplay instruction,Yaddressisby1ReadDisplay11ReadReadsdata(DB0:7)fromdataRAMtothedatasbitL_SET=sbitL_SET==sbitTESTfloatucharX1[]=};/*欢*/ucharcodeX2};/*迎*/ucharcodeX3};/*使*/ucharcodeX4};/*用*/ucharcodeX5};/*图*/ucharcodeX6};/*形*/ucharcodeX7};/*点*/uchar};/*点*/ucharcodeX8};/*阵*/ucharcodeX9};/*12*/ucharcodeX10[]={};/*8x*/ucharcodeX11[]={};/*64*/ucharcodeX12[]={};/**/ucharcodeX13[]=};/*全黑*/ucharcodeX14};/*全白ucharcode};/*上边*/ucharcodeX16[]={};/*下边*/ucharcodeX17[]={};/*左边*/ucharcodeX18[]={};/*右边*/ucharcodeX19[]={};/*左上*/ucharcodeX20[]={};/*右上*/ucharcodeX21[]={};/*左下*/ucharcodeX22[]={};/*右下*/ucharcodeX23[]={};/*空白*/void{PCON=0x80;TMOD=0X21;};/*右下*/ucharcodeX23[]={};/*空白*/void{PCON=0x80;TMOD=0X21;SCON=TH1=0XFa;TL1=0XFa;TR1=1;ESTH0=0;TL0=0;TR0=1;ET0=EA=}void{uchari,j;a