单片机原理及应用（双语版·新形态版） 课件 第4章MCS51汇编语言程序设计

IntroductoryMicrocontrollerChapter4AssemblyLanguageProgrammingfortheMCS-51ProgrammingLanguageTypesint

x,y;floatv,i;Main() { x=1; while(x<55){ProgrammingLanguageTypesLinear: Assemblylanguage 直线式流程 汇编语言

int

x,y;floatv,i;Main() { x=1; while(x<55){Function-driven: C,Pascal,Modula-2 功能模块Object-oriented: C++,Java,Ada

面向对象

Event-driven: VisualBASIC(VB) 事件驱动

ProgrammingLanguageTypesLinear: AssemblylanguageUseflowchart流程图YNActionDecisionBeginorEndDefine定义Flowchart流程图EditSourceProgram编辑源程序Assemble汇编

Download下载

Run运行Errors?错误

Runtimeerrors?FinishedYNYNPROGRAMDESIGNPROCEDUREDefine定义Flowchart流程图EditSourceProgram编辑源程序Assemble汇编

Download下载

Run运行Errors?错误

Runtimeerrors?FinishedYNYNPROGRAMDESIGNPROCEDUREAssemblyLanguageProgramFormatLABEL OPCODE

OPERANDCOMMENTBEGIN: MOVA,#34h;loadaccumulator

MOV0C6h,A标号操作吗操作数注释AssemblyLanguageProgramFormatLABEL OPCODE

OPERANDCOMMENTBEGIN: MOVA,#34h;loadaccumulator

mov0c6h,aNotcasesensitiveAssemblyLanguageProgramFormatLABEL OPCODE

OPERANDCOMMENTbegin: mova,#34h;loadaccumulator

MOV0C6h,ANotcasesensitiveAssemblyLanguageProgramFormatLABEL OPCODE

OPERANDCOMMENTBEGIN: MOVA,#34h;loadaccumulator

MOV0C6h,AFirstdigitmustbeanumberAssemblyLanguageProgramFormatLABEL OPCODE

OPERANDCOMMENTBEGIN: MOVA,#34h;loadaccumulator

MOV0C6h,AUseacolontoshowitisalabel MOV A,#34hEND: SJMP ENDAssemblyLanguageProgramFormatUseof$asashorthandlabel MOV A,#34h SJMP $Howcanwestopthemicrocontroller? SJMP $UseanendlessloopFINISH: SJMP FINISHWhatarePseudo-Instructions?伪指令

Yeudos

=

NotrealEditAssembleRunSourceProgramObjectProgramReadablebyhumansReadablebyprocessorsMOVA,06hMOV27h,AINCA100101011001100111001011EditAssembleRunSourceProgramPseudo-instructions伪指令

ORG2000hBEGIN: MOVA,#26h RR A RRA ANLA,67h MOV0D6,#45h DJNZ0D6,DEL INCAPSEUDO-INSTRUCTIONSINASM51伪指令

ORG2000h-Downloadprogramat2000h1FFF1FFE1FFD2007200620052004200320022001200020082009ORG=origin

ORG1FFDhBEGIN: MOVA,#26h RRA RRA

ORG2006hCHCK: MOV0D6,#45h DJNZ0D6,DEL INCAPSEUDO-INSTRUCTIONSINASM51伪指令

1FFF1FFE1FFD2007200620052004200320022001200020082009ORG2000h-Downloadprogramat2000hPSEUDO-INSTRUCTIONSINASM51伪指令

REDEQU40h-Equatenametovalue;TrafficlightsMOV40h,#21hMOV41h,#20hGO EQU20hSTOP EQU21hROAD1EQU40hROAD2 EQU41hMOVROAD1,#STOPMOVROAD2,#GOPSEUDO-INSTRUCTIONSINASM51伪指令

REDBITP1.5-Equatenametobit RED BITP1.5 MOV R6,#0A4h DJNZ R6,$ SETB RED MOV R6,#55h DJNZ R6,$ CLR RED

ORG1FFDh DB00h,55h DB27h ORG2005h DB‘Hello’PSEUDO-INSTRUCTIONSINASM51伪指令

DB=databyte-Putbytesinmemory1FFF1FFE1FFD2007200620052004200320022001200020082009006F6C6C65485527PROGRAMMINGEXAMPLES

4.4Datamanipulation数据处理

4.5Arithmeticcalculation计算

4.6Logicalexpressions逻辑4.7Timedelays延时4.8Textmanipulation文本操作

4.9Programcontrol程序控制4.4.1CopyingdataininternalmemoryCopytheblockofdataininternalRAM25h-45htoaddresses55h-75h25h56h55h45h75h26h1.UseregistersR0andR12.MOVinindirectmode3.IncrementR0andR1MMNNPPQQRRStart55hintoR1YNCopydata@R0toaddress@R1R0=46h?FinishStart25hintoR0IncrementR0IncrementR1LOOP:Example4.4.1MOV@R1,@R0ACCA累加器Direct直接寻址@Ri间接寻址Rn寄存器#data立即数PossibleDataTransferInstructionsMOV,Start55hintoR1YNCopydata@R0toaddress@R1R0=46h?FinishStart25hintoR0IncrementR0IncrementR1LOOP:Example4.4.1START: MOV R0,#25h MOV R1,#55hLOOP: MOV A,@R0 MOV @R1,A INC R0 INC R1 CJNE R0,#46h,LOOP SJMP $Example4.4.1ShandongUniversityofScienceandTechnologyMicrocontrollerTheoryandApplicationsStudent’sWorkbookforClassexercisesandHomeworkStudent’sname(Chinese)_______Student’sname(Pinyin)________StudentIDnumber____________Class___________ForwritingprogramspleaseusetheWorkbookForthefollowingdrawaflowchartandwriteaprogram..Question4.10.1Question4.10.4(“reverse”)inyourWorkbookPages74-75Question4.10.1Put3Bhintolocations40h-DFh40hintoR0YNR0=E0h?FinishStart3Bhinto@R0IncrementR0LOOP: MOVR0,#40hLOOP:MOV@R0,#3Bh INCR0 CJNER0,#0E0h,LOOP SJMP $Question4.10.4Copy25h-45hto55h-75hinreverseorder55h45h75h25hMMNNPPQQQuestion4.10.4Copy25h-45hto55h-75hinreverseorder55h45h75h25hMMNNPPQQStart75hintoR1YNCopydata@R0toaddress@R1R0=46h?FinishStart25hintoR0IncrementR0DecrementR1LOOP:START: MOV R0,#25h MOV R1,#75hLOOP: MOV A,@R0 MOV @R1,A INC R0 DEC R1 CJNE R0,#46h,LOOP SJMP $Question4.10.4Sortthenumbersintheblock30h-5Fh(Highestnumberinhighestaddress)(Totalof30hnumbers)4.4.2SortingablockofdataUsetheBubble-Sort冒泡排序methodTheBubble-Sortmethod4.4.2SortingablockofdataStartScan1Scan2Scan3Scan4Scan5Scan6Scan711991991991991991991991421142142142142142142314218787878787873871646464642587364125252519925643251191919642525319136419191919331Example4.4.2StartScan1119914219913199142142871993332519987878787199199252525252519646464646464646419191919191919Example4.4.2StartScan1Scan2Scan3Scan4Scan5Scan6Scan7119919919919919919919914211421421421421421423142187878787878738716464646425873641252525199256432511919196425253191364191919193310intoR7(count)30hintoR0Data@R1toACarry=1?A–data@R0Start31hintoR1Data@R1intoAYNCHECK:SCAN:ExchangedatainAwithdata@R0StoreA@R1IncrementR0IncrementR7(count)R0=5Fh?IncrementR1R7=2Fh?FinishYYNNCONTINUE:START: MOV R7,#00hSCAN: MOV R0,#30h MOV R1,#31hCHECK: MOV A,@R1 CLR C SUBB A,@R0 JNC CONTINUE MOV A,@R1 XCH A,@R0 MOV @R1,ACONTINUE: INC R0 INC R1 CJNE R0,#5Fh,CHECK INC R7 CJNE R7,#2Fh,SCAN SJMP $Example4.4.20intoR7(count)30hintoR0Data@R1toACarry=1?A–data@R0Start31hintoR1Data@R1intoAYNCHECK:SCAN:ExchangedatainAwithdata@R0StoreA@R1IncrementR0IncrementR7(count)R0=5Fh?IncrementR1R7=2Fh?FinishYYNNCONTINUE:Howmanyscansrequired?8numbersrequires7scans1numberrequires0scansNnumbersrequiresN-1scans30hnumbersrequires2FhscansInternalRAM40h-7FhtoexternalRAMat7000h7000h40h7FhExternalRAMInternalRAMA4.4.3Copyingdatatoexternalmemory4.4.3CopyingdatatoexternalmemoryR0=80h?StartPut40hintoR0Put7000hintoDPTRData@R0to@DPTRIncrementR0IncrementDPTRFinishYNLP:InternalRAM40h-7FhtoexternalRAMat7000h40h7FhExternalRAMInternalRAM7000hA MOV R0,#40h MOV DPTR,#7000hLP: MOV A,@R0 MOVX @DPTR,A INC R0

INC DPTR CJNE R0,#80h,LP

SJMP $4.4.4FindingthelargestvalueindataFordatainaddresses20h-4Fhfindthelargestvalue.Storetheresultinlocation60h.20h4Fh21h2536C5774E60h2536C5Copydata@R0toaddress60h20hintoR0FinishIncrementR0StartCopydata@R0toaddress60hIsdata@R0>datainaddress60h?R0=50h?YYNNLOOP:Example4.4.4CONT:START: MOV R0,#20h MOV 60h,@R0LOOP: INC R0 CJNE R0,#50h,CONT SJMP $ ;FinishCONT: MOV A,@R0 CLR C SUBB A,60h ;@R0-(60h) JC LOOP ;if(60h)>A MOV 60h,@R0;@R0to60h SJMP LOOPExample4.4.4Trythefollowing..Question4.10.18Question4.10.19Question4.10.23Pages77-78(4Fh)=77h“Address4Fhcontainsdata77h”SP=60h;(30h)=24h;(31h)=10hPUSH30h;SP=61h;(SP)=24hPUSH31h;SP=62h;(SP)=10hPOP DPL;SP=61h;DPL=10hPOP DPH;SP=60h;DPH=24hQuestion4.10.1830h31h60h61h62hSPDPTRDPLDPH24101024SPSP1024StackA=84h;R0=4Bh;(40h)=20h;(4Bh)=7FhQuestion4.10.19AR0(40h)(4Bh)Start844B207FMOVA,@R07F4B207FMOV@R0,40h7F4B2020MOV 40h,A7F4B7F20MOV R0,#35h7F357F20Question4.10.23DPTRAP0MOVP0,#00h00MOVA,#8Ch8C00MOVDPTR,#8000h80008C00MOVX@DPTR,A80008C00INCDPTR80018C00INCA80018D00MOVX@DPTR,A80018D00INCDPTR80028D00INCA80028E00MOVX@DPTR,A80028E00MOVDPTR,#8001h80018E00MOVXA,@DPTR80018D00MOVP0,A80018D8DPROGRAMMINGEXAMPLES

4.4Datamanipulation数据处理

4.5Arithmeticcalculation计算

4.6Logicalexpressions逻辑4.7Timedelays延时4.8Textmanipulation文本操作

4.9Programcontrol程序控制Usethestacktoevaluatethefollowing:RAMMemoryaddresses:- V:50h

W:51h X:52h Y:53h PutZintoaddress60h4.5.1UsingthestackforarithmeticADD A,YPUSH ACC ;W+Y;AllitemsonthestackPOP Z ;W+YPOP ACC ;V+XCLR CSUBB A,ZMOV Z,A ;Z=(V+X)-(W+Y)POP ACC ;V+WADD A,ZMOV Z,A;Z=(V+W)+(V+X)-(W+Y)SJMP $V EQU 50hW EQU 51hX EQU 52hY EQU 53hZ EQU 60hMOV A,V ADD A,W

PUSH ACC;V+WMOV A,VADD A,XPUSH ACC;V+XMOV A,WReturnthevalueofanyofthefirst16primenumbers质数

usingalook-uptable.4.5.2Usingalook-uptableforarithmetic

ORG 0000h

MAIN: MOV DPTR,#0200h MOVC A,@A+DPTR SJMP $

ORG 0200hTABLE: DB 0,1,2,3,5,7,11 DB 13,17,19,23,29 DB 31,37,41,43,47200h000000010203Main0507Returnthevalueofanyofthefirst16primenumbers质数

usingalook-uptable.

ORG 0000h

MAIN: MOV DPTR,#0200h MOVC A,@A+DPTR SJMP $

ORG 0200hTABLE: DB 0,1,2,3,5,7,11 DB 13,17,19,23,29 DB 31,37,41,43,47200h000000010203Main0507A=44.5.2Usingalook-uptableforarithmeticSecondmethod:

ORG 0000h

MAIN: INC A INC A MOVC A,@A+PC SJMP $TABLE:

DB 0,1,2,3,5,7,11 DB 13,17,19,23,29 DB 31,37,41,43,47000000010203MainSJMP$05070B11A=4A=6MOVC+6A=54.5.2Usingalook-uptableforarithmeticForthefollowingdrawaflowchartandwriteaprogram..Question4.10.2Pages74-75Question4.10.2Put5…8into55h…58h.Add.Putresultin60h55h56h58h60h57h05060708Result59hQuestion4.10.2Put5…8into55h…58h.Add.Putresultin60hStart05into55hFinish55intoR0A=A+@R006into56h07into57h08into58hA=0INCR0R0=59h?Ainto60hYNLOOP: MOV 55h,#05h… MOV R0,#55h CLR ALOOP: ADD A,@R0 INC R0 CJNER0,#59h,LOOP MOV 60h,A SJMP $4.5.3SignedarithmeticcalculationsACOVMOVA,#24h+24h00ADDA,#24h+48h00CLRC+48h00SUBBA,#30h+18h00CLRC+18h00ADDA,#10101011b(-55h)-3Dh00CLRC-3Dh00SUBBA,#10011011b(-65h)+28h008-bitsignednumbers:-128to+1274.5.4Multi-byteunsignedcalculations

7E04h+50EDhPutresultin50h(low)and51h(hi)

30h31h40h41h0450h51h60h61h7EED50F1CEMOV A,30hADD A,40h ;AddlobytesMOV 50h,A ;Storelo-byteMOV A,31hADDC A,41h ;Hibytes+CMOV 51h,A ;Storehi-byte 4.5.4Multi-byteunsignedcalculations

7E04h-50EDhPutresultin60h(low)and61h(hi)

30h31h40h41h0450h51h60h61h7EED50172DMOV A,30hCLR CSUBB A,40h ;SublobytesMOV 60h,A ;Storelo-byteMOV A,31hSUBB A,41h ;Hibytes–CMOV 61h,A ;Storehi-byteC=14.5.5Pseudo-randomnumbers伪随机数1269125189132112092301671509123255573413651TestingofDigitalSystems数字系统Randomnoise随机噪声Pseudo-randomnumbers为随机数12691251891321120923016715091232555713651Xo=SeedConstantMultiplier4.5.5Pseudo-randomnumbers伪随机数4.5.5Pseudo-randomnumbers伪随机数1265X0=4iXi5*XiXi+10420212101215535257473584.5.5Pseudo-randomnumbers伪随机数12651010110110010100Dividea16-bitnumberby256Modulusislowbyteofthe16-bitnumber4.5.5Pseudo-randomnumbers(Page61)12691251891321120923016715091232555713651;LetSeedX(0)=57h,multiplierA=100(64h)

SEEDEQU 57h MOV40h,#SEED ;Seedinto40h MOV R0,#40h MOV A,@R0 ;SeedintoALOOP: MOV B,#64h ;Multiplier=100 MUL AB ;Multiplier*X(i） CJNEA,#00h,CONT MOVA,#0FFh ;Complement0valueCONT: INC R0 MOV @R0,A ;X(i+1)intoRAM CJNER0,#70h,LOOP SJMP $4.5.5Pseudo-randomnumbers(Page60)12691251891321120923016715091232555713651iX(i)100*X(i)Low_byte(100*X(i))X(i+1)057h21FChFChFCh1FCh6270h70h70h270h2BC0hC0hC0h3C0h4B00h00hFFh4FFh639Ch9Ch9ChFillinthetablesinyourtextbookforthefollowing…Question4.10.24Question4.10.25Pages79Question4.10.24Question4.10.24DPTRACORG0000hMOVDPTR,#8000h8000MOVA,#0FFh8000FFCLRC8000FF0SUBBA,#56h8000A90MOVCA,@A+DPTR8000260SJMP$8000260ORG80A8hDB0FFh,26h,55h,00hQuestion4.10.25ABORG0000hMOVA,#0C6hC6MOVB,#23hC623DIVAB0517CJNEB,#17h,NOMOD0517MOVA,#0FFhFF17SJMPFINISHFF17NOMOD:CLRANENEFINISH:SJMP$FF17PROGRAMMINGEXAMPLES

4.4Datamanipulation数据处理

4.5Arithmeticcalculation计算

4.6Logicalexpressions逻辑4.7Timedelays延时4.8Textmanipulation文本操作

4.9Programcontrol程序控制4.6.1SimplelogiccalculationTakethenumbers1to9andExclusive-OReachonewiththedatainaddress5Ch.Puttheresultsinlocations71hto79h5C77767574737271787901NNXXYYZZ0203Ex-ORR0R1YN01hintoR071hinR1IncrementR1PutAintoaddress@R1AEx-OR(5Ch)R0=0Ah?R0intoA71hintoR1IncrementR0FinishStartLOOP:(5Ch)=Datainlocation5ChExample4.6.1START: MOV R0,#01h MOV R1,#71hLOOP: MOV A,R0 XRL A,5Ch MOV @R1,A INC R0 INC R1 CJNE R0,#0Ah,LOOP SJMP $ ;FinishExample4.6.14.6.2UsingstackforlogicRAMMemoryaddresses:- U:30h

V:31h W:32h X:33h Y:34h Z:35h P:40hP EQU 40hU EQU 30hV EQU 31hW EQU 32hX EQU 33hY EQU 34hZ EQU 35hANDExcl-ORORPOP P ;Y*ZXRL A,P;(U+V)*(W+X)+(Y*Z)MOV P,AMOV A,YANL A,ZPUSH ACC ;Y*ZMOV A,UORL A,VPUSH ACC ;U+VMOV A,WORL A,XPUSH ACC ;W+X;ResultsnowonstackPOP P ;W+XPOP ACC ;U+VANL A,P ;(U+V)*(W+X)Example4.6.2Nowtrythefollowing…Question4.10.3“Rotate” (Program)Question4.10.5 (Flowchart&program)Page74Question4.10.3Put128into70h.Rotaterighttwice.Resultin71h. MOV A,#80h MOV 70h,A RR A RR A MOV 71h,A SJMP $100000000010000080h=12820h=32Question4.10.5Countnegnumbersin40h-5Fh.Count:10h10110001CHKNEG:;ifC=1thenincrementCOUNT RLC A JNC NEXTONE INC COUNTNEXTONE: RRC A ;Restorevalue RET1CCOUNT=040hintoR0FinishCopy@R0toAStartR0=60?LOOP:4.10.5SubroutineCHKNEGIncrementR0COUNT EQU 10h MOV R0,#40h MOV COUNT,#00hLOOP: MOV A,R0 ACALL CHKNEG INC R0 CJNE R0,#60h,LOOP SJMP $CHKNEG: RLC A JNC NEXTONE INC COUNTNEXTONE: RRC A RET4.10.5PROGRAMMINGEXAMPLES

4.4Datamanipulation数据处理

4.5Arithmeticcalculation计算

4.6Logicalexpressions逻辑4.7Timedelays延时4.8Textmanipulation文本操作

4.9Programcontrol程序控制PROGRAMMINGEXAMPLES

4.4Datamanipulation数据处理

4.5Arithmeticcalculation计算

4.6Logicalexpressions逻辑4.7Timedelays延时4.8Textmanipulation文本操作

4.9Programcontrol程序控制Whydoweneedtimedelays?Whydoweneedtimedelays?TrafficlightcontrolWhydoweneedtimedelays?Generatingasquarewave4.7.1SoftwaregenerationoftimedelayProgramasubroutinetorunfor100msClockspeed=12MHzWeneed1200000cycles100ms12MHzStartsubroutineReturnR1=0?DecrementR1XXintoR0YYintoR1DecrementR0R0=0?NNYY4.7.1SoftwaregenerationoftimedelaySTART: MOV R0,#XXhLOOP1: MOV R1,#YYhLOOP2: DJNZ R1,$ DJNZ R0,LOOP1 RET4.7.1Softwaregenerationoftimedelay100ms12MHzStartsubroutineReturnR1=0?DecrementR1XXintoR0YYintoR1DecrementR0R0=0?NNYYLOOP1:LOOP2:HowmanytimespastLOOP1?XXHowmanytimespastLOOP2?XX*YY4.7.1SoftwaregenerationoftimedelaySTART: MOV R0,#XXh

;onetimeLOOP1: MOV R1,#YYh

;XXtimesLOOP2: DJNZ R1,$ ;XX*YY

DJNZ R0,LOOP1 ;XXtimes RET ;onetime4.7.1SoftwaregenerationoftimedelaySourceCode#TimesexecutedTotalclockcyclesSTART:MOVR0,#XXh12112LOOP1:MOVR1,#YYh12XX12*XXDJNZR1,$24XX*YY24*XX*YYDJNZR0,LOOP124XX24*XXRET24124Totalnumberofcycles12+12*XX+24*XX*YY+24*XX+24TimebudgetfortheprogramSTART: MOV R0,#XXLOOP1: MOV R1,#YYDJNZ R1,$ DJNZ R0,LOOP1 RETSTART: MOV R0,#0FFhLOOP1: MOV R1,#0C3h DJNZ R1,$ DJNZ R0,LOOP1 RETRoundingerror舍入误差 =.22%IfYYissmall(<50)thendecreaseXXWhatisthelongesttimedelay?StartsubroutineReturnR1=0?DecrementR1XXintoR0YYintoR1DecrementR0R0=0?NNYY4.7.1SoftwaregenerationoftimedelayFFFFSourceCode#TimesexecutedTotalclockcyclesSTART:MOVR0,#0FFh12112LOOP1:MOVR1,#0FFh12FF12*FFDJNZR1,$24FF*FF24*FF*FFDJNZR0,LOOP124FF24*FFRET24124Totalnumberofcycles12*FF+24*FF*FF+24*FFTimebudgetfortheprogramDecrementR1ReturnDecrementR2YYintoR1XXintoR0ZZintoR2DecrementR0StartsubroutineR2=0?R1=0?R0=0?Use3loopsThereisaproblemwithsoftwaretimedelays“Busywaiting”忙等待CPUisbusy-butdoingnothing!TimedelaysforlightsCheckforcarsOscillatorInterruptCPUROMRAMTimer1Timer0I/OportsSerialExternalinterruptsCounterinputsP0P1P2P3TXDRXD8051MicrocontrollerHardwaretimersPROGRAMMINGEXAMPLES

4.4Datamanipulation数据处理

4.5Arithmeticcalculation计算

4.6Logicalexpressions逻辑4.7Timedelays延时4.8Textmanipulation文本操作

4.9Programcontrol程序控制Textmanipulation4.8.1Convert4-bitbinarytohexASCII7DData@R010100111Data@R011111101Putresultinlocation36hBinHexASCIIAction0000030h+30h0001131h+30h0010232h+30h0011333h+30h0100434h+30h0101535h+30h0110636h+30h0111737h+30hBinHexASCIIAction1000838h+30h1001939h+30h1010A41h+37h1011B42h+37h1100C43h+37h1101D44h+37h1110E45h+37h1111F46h+37hIFNUMBER<10THENADD30h

(togive0…9)IFNUMBER>9THENADD37h

(togiveA…F)4.8.1Convert4-bitbinarytohexASCII MOVA,@R0 ANL A,#0Fh;Getlownibble PUSHACC;Pushtostack CLR C;ResetCflag SUBBA,#0Ah;Isit<10? POPACC JC NUMBERSLETTERS: ADD A,#37h ;InrangeA…F SJMPSAVENUMBERS: ADD A,#30h;Inrange0…9SAVE: MOV 36h,A SJMP$4.8.1Convert4-bitbinarytohexASCII4.8.2ConvertASCIIvaluetobinaryPortP2RegisterR700000110636hASCII001101106BinNum

ASCIIAction0000030h-30h0001131h-30h0010232h-30h0011333h-30h0100434h-30h0101535h-30h0110636h-30h0111737h-30hBinNum

ASCIIAction1000838h-30h1001939h-30h4.8.2ConvertASCIIvaluetobinarySTART:MOVP2,#0FFh;Port2asinputLOOP: MOVR7,P2 ;ReadPort2 MOVA,R7 ;ASCIItoA CLRC SUBBA,#30h ;A-30h=binary MOVR7,A ;ResulttoR7 SJMP LOOP4.8.2ConvertASCIIvaluetobinaryPleasetry… Question4.10.22 (Page78) MOV A,___ ;BtoA ____ A,#0F0h ;Gethighnibble SWAP _____ ;Swapnibbles ____ ACC ;Pushtostack CLR ____ ;ResetC SUBB A,___ ;A-10 POP ACC ___ LOWER ADD A,#07h ;>=10,add37hLOWER:ADD A,#30h ;<10add30h MOV ___,A ;SendtoPort3 RET ;ReturnQuestion4.10.22BANLAPUSHC#0AhJCP34.8.3Stringstorageandretrieval(P67)Returnthevalueofanyofthefirst16primenumbers质数

usingalook-uptable.Usingalook-uptableforarithmetic

ORG 0000h

MAIN: MOV DPTR,#0200h MOVC A,@A+DPTR SJMP $

ORG 0200hTABLE: DB 0,1,2,3,5,7,11 DB 13,17,19,23,29 DB 31,37,41,43,47200h000000010203Main0507SendoutofPort3themessage“Login:”asASCIIcharacters

ORG 0000h

MOV DPTR,#8000hLOOP: CLR A MOVC A,@A+DPTR MOV P3,A INC DPTR CJNE A,#3Ah,LOOP SJMP $

ORG 8000h DB “Login:”8000h00004C6F6769Main6E3A4.8.3Stringstorageandretrieval(P67)4.8.4TextformattingcharactersNameShortASCIIActionCarriageReturnCR0DhTobeginningoflineLineFeedLF0AhDowntonextlineFormFeedFF0ChStartanewpageTabTAB09hNexttabpositionASCIIZeroASC000hIndicatestheendofastringDB “WelcometotheNetwork”,0Dh,0AhDB “Wecloseat5pmtoday”,0Dh,0AhDB 0Dh,0Ah,09h,09hDB “Pleaselogin:“,00hWelcometotheNetworkWecloseat5pmtoday Pleaselogin:4.8.4TextformattingcharactersP08051P2.0Ready“WelcometoBeijing”totheprinter.Send

Strobeaftereachcharacter.

WaitforReady

pulsebeforenext.EndwithASC0.

StrobeP2.14.8.5Sendingastringtoprinter010101111W1YNChar=ASC0?Storemessageinmemory4.8.5InitialiseDPTRStartSendchar@DPTRtoP0Readypulse?SendStrobepulseFinishINCDPTRYCONT:NEXT:N4.8.5PRINTER EQU P0STROBE BIT P2.1READY BIT P2.0 ORG 8000h DB “WelcometoBeijing”,00h

ORG 0000h MOV DPTR,#8000hNEXT: CLR A MOVC A,@A+DPTR MOV PRINTER,A ;Printchar SETB STROBE ;SendStrobe NOP ;pulse CLR STROBE CJNE A,#00h,CONT ;ASC0? SJMP $ ;FinishCONT: SETB READY ;Waitfor JNB READY,$ ;Readypin JB READY,$ ;togohigh INC DPTR ;Nextchar SJMP NEXT4.8.5Pleasetry… Question4.10.26 (Page80)Question4.10.26ACORG0000hMOVA,#55h55CLRC550RLCAAA0JCDETECTAA0ACALLROTATEAA0DETECT:SJMP$660ROTATE:MOVA,#66h660RET660PROGRAMMINGEXAMPLES

4.4Datamanipulation数据处理

4.5Arithmeticcalculation计算

4.6Logicalexpressions逻辑4.7Timedelays延时4.8Textmanipulation文本操作

4.9Programcontrol程序控制4.9.1N-waybranching行多方分支Home-controlsystem(HCS)LightsTVCookerGatesWaterheaterA02hFunctionDeviceLabelname1OutsidelightsLIGHTS:2AirconditioningAIRCON:3SecuritysystemSECURITY:4CurtainsCURTAINS:5DoorlocksDOORS:6TelevisionTV:7CookerCOOKER:8RefrigeratorFRIDGE:9MaingatesGATES:10WaterheaterWATER:4.9.1N-waybranching行多方分支MainProgramJumptableSubroutinesMAIN: MOV P0,#0FFh ;MakeP0aninput MOV DPTR,#TABLELOOP: MOV A,P0 ;Readfunction JZ LOOP ;LOOPifA=0 RL A ;MultiplyAby2 JMP @A+DPTR ;Jumptotable;+++++++++++++++++++++++++++++++++++++++TABL