单片机原理及应用（双语版·新形态版） 课件 第5章MCS51的中断处理

IntroductoryMicrocontrollerTheoryandApplicationsChapter5InterruptHandlingontheMCS-51ThisistheManagingDirector…Urgentprobleminsalesdepartment….Emailarrived!!中断Ring,ring,ring….Excuseme!CanIhaveawordwithyou?Interrupts1432765MainprograminstructionsInterrupt中断Mainprograminstructions1432765MainProgramstopsrunningProgramCounterissavedontheStacubprogramInterruptServiceRoutine(ISR)中断服务程序JumpstoanISRincodememorubprogramInterruptServiceRoutine(ISR)RETIPOPstheReturnAddressfromtheStack12765431432MainprograminstructionsWhat’sthedifferencebetweenaSubroutine子程序andanInterrupt中断?ASubroutineiscalledbyaprogramMOV A,#56hACALL DELAY…………….AnInterruptiscausedbyavoltagechangeintotheCPUInterruptSourcesINT0INT1RESETSerialPortTimersExternalInterruptsTXDRXDInterruptSourcesCPUINT0INT1Timer0Timer1SerialPortINT0RESETChangeofvoltageOverflow溢出ofTimerData数据readyInterruptSourceFlagsCPUINT0INT1Timer0Timer1SerialPortINT0RESETIE0IE1TI/RITF0TF1InterruptControlCircuitEA--ESET1EX1ET0EX0InterruptEnablingandDisabling允许和屏蔽usingIERegisterEnableAllSerialT1T0INT0INT10--10010EnableAllSerialT1T0INT0INT1Whichinterruptsarenowenabled?NONEInterruptEnablingandDisabling允许和屏蔽usingIERegister1--00000EnableAllSerialT1T0INT0INT1Whichinterruptsarenowenabled?NONEInterruptEnablingandDisabling允许和屏蔽usingIERegister1--01010EnableAllIfEA=0 thenallaredisabledIfEA=1 theninterruptscan beenabledInterruptEnablingandDisabling允许和屏蔽usingIERegisterWhathappensiftwointerruptsarriveatthesametime?ExternalInterrupt0HighestpriorityTimer0ExternalInterrupt1Timer1SerialPortLowestpriority5.5.1PriorityRankingOrder优先权等级次序1432765MainprograminstructionsINT0TIMER1HigherpriorityLowerpriority1321432765RETIISRforINT01321432765ISRforINT0RETIISRforTIMER1RETI1321321432765ISRforINT0RETIISRforTIMER1RETI1321321432765ISRforINT0ISRforTIMER11325423MainprograminstructionsWhathappensifoneinterruptisinterruptedbyanother?1321432765RETILowerpriorityHigherpriorityISR1Interrupt21321432765ISR1RETIISR2RETI1321321432765ISR1ISR21325423Mainprograminstructions1321432765LowerpriorityHigherpriorityISR1Interrupt2IfInterrupt2hasthehigherpriority…..4RETI1432765ISR112ISR21234RETIMainprograminstructions1432765ISR11234ISR1ISR21234RETIRETIMainprograminstructions1432765ISR1123445ISR1ISR21234RETIRETIMainprograminstructionsPleasetrythefollowing..Question5.10.2Question5.10.3Question5.10.4Question5.10.5Page99Question5.10.2INT0&Timer1togetherPriorities:INT0>Timer1RunINT0ISRthenTimer1ISR+++++++++++++++++++++++++++++++++Question5.10.3

DuringSerialPortISRreceivesTimer0interrupt.Whataction?Priorities:Timer0>SerialPortTimer0willinterruptSerialISR,runTimer0ISR,thencompleteSerialISRQuestion5.10.4IE=08h.INT0andTimer1togetherIfIE=08hthenEA=0Allinterruptsdisabled+++++++++++++++++++++++++++++++++Question5.10.5

DuringTimer1ISRreceivesSerialinterrupt.Whataction?Priorities:Timer1>SerialPortTimer1ISRwillfinish,then,runSerialISR---PSPT1PX1PT0PX0InterruptPriority-IPSerialT1T0INT0INT1SETBPSSETBPT05.5.4ChangingtheInterruptPrioritiesMOVIP,#00010010bMOVIP,#12hTimer0HighprioritySerialPortHighpriorityExternalInterrupt0LowpriorityExternalInterrupt1LowpriorityTimer1LowpriorityPriorityRankingOrder优先权等级次序InterruptControlCircuitPleasetrythefollowing..Question5.10.6Question5.10.7Page100PleasechangetoIE=82hQuestion5.10.6IP=04hIE=9FhWhileINT0ISRisrunning,INT1receivedIE=10011111bAllinterruptsenabledIP=00000100bINT1hashighpriorityINT0ISRisinterrupted,INT1ISRruns,thenINT0willcomplete.+++++++++++++++++++++++++++++++++Question5.10.7IP=10hIE=82hTimer0ISRreceivesSerialinterrupt.IE=10000010bOnlyTimer0enabledSerialinterruptdoesnotrunubprogramInterruptServiceRoutine(ISR)JumpstoanISRincodememoryWhereistheISR?5.6MemorylocationsCodeMemory000000130023001B0003000BResetExternalInterrupt0Timer0ExternalInterrupt1Timer1SerialportInterrupthandlerInterruptServiceRoutine(ISR)中断服务程序INTERRUPTFACILITIESTYPEFLAGISRADDRESSReset-0000hExternalInt0IE00003hTimer0TF0000BhExternalInt1IE10013hTimer1TF1001BhSerialPortTI/RI0023hResetExternalInterrupt0Timer0ExternalInterrupt1Timer1SerialportJumpovertheISRstoMainUnusedmemory0050hMain000000130023001B0003000BSJMP0050h

ORG 0000h SJMP 0050h ;JumpoverISRs

ORG 0003h AJMP EXTINT0 ;ISRforExtInt0

ORG 000Bh AJMP TIMER0 ;ISRforTimer0

ORG 0013h AJMP EXTINT1 ;ISRforExtInt1

ORG 001Bh AJMP TIMER1 ;ISRforTimer1

ORG 0023h AJMP SERIAL ;ISRforSerialPort

ORG 0050h ;StartofMainprogramMAIN: UnusedmemoryMainMainORG0050hLabelSJMPMAINSJMP0050h

ORG 0000h SJMP MAIN ;JumpoverISRs

ORG 0003h AJMP EXTINT0 ;ISRforExtInt0

ORG 000Bh AJMP TIMER0 ;ISRforTimer0

ORG 0013h AJMP EXTINT1 ;ISRforExtInt1

ORG 001Bh AJMP TIMER1 ;ISRforTimer1

ORG 0023h AJMP SERIAL ;ISRforSerialPortMAIN: ;StartofMainprogram

ORG 0000h SJMP MAIN ;JumpoverISR

ORG 0003h AJMP EXTINT0 ;ISRforExtInt0MAIN ;StartofMainprogram

SJMP $EXTINT0:

RETIWhenonlyoneinterruptisenabled…ExternalInterruptsINT0andINT1Typeofinterrupt….ExternalInterruptsINT0andINT1Interruptcausedby…. EITHERalowlevel电平触发ORahigh-to-lowtransition(edgetriggering) 边沿触发Vint05IT0=1IT0=0(InterruptType)timeTF1TR1TF0TR0IE1IT1IE0IT0TimerControlTCONInterruptTypeInterruptEdgeflagSetwhenInterruptlinegoeslowIT0=0IT1=0Interruptswhenlow-levelIE0/IE1willbesetIE0/IE1mustbeclearedbytheprogram

CLRIE0

IT0=1IT1=1Interruptswhenhigh-to-lowedgetransitionIE0/IE1willbesetIE0/IE1willbeclearedwhenISRstartsExternalInterruptsINT0andINT1015.9.1Example:ControloftrafficlightsRunamainprogramwhichisinterruptedwhenacarblocksasensor.Lightsshouldthenchangetoallowthevehicletoproceed.5.9.1Example:ControloftrafficlightsSensor0Red0Green1Sensor101INT0Direction0Direction1+5VP.1.0P.1.1INT0Sensor0Sensor10015.9.1PhotocellStartEnableinterruptEdgetriggeringDirectionflag=0MainProgramactivity5.9.1DIRN BIT 20.0h;FlagforGreendirection ORG 0000h SJMPSTART ORG 0003h AJMPISRINT0 ;ISRforINT0START: SETBEA SETBEX0 ;EnableinterruptINT0 SETBIT0 ;Setforedgetriggering CLR DIRN

;Setdirectiontobe0MAIN: NOP NOP ;Mainprogram SJMPMAIN01Sensor1Sensor0Light0Light15.9.1+5VP.1.0P.1.1INT0Sensor0Sensor1LightNoLightHighRLowR1005.9.1Sensor0high?Direction=0?Direction=1?ChangetoDirection0ChangetoDirection1ReturnDirectionflag=1ISRReturnYYNNYNROAD0:ROAD1:Directionflag=05.9.1Sensor0high?Direction=0?Direction=1?ChangetoDirection0ChangetoDirection1ReturnDirectionflag=1ISRReturnYYNNYNROAD0:ROAD1:Directionflag=05.9.101Sensor1Sensor0Light0Light15.9.1Sensor0high?Direction=0?Direction=1?ChangetoDirection0ChangetoDirection1ReturnDirectionflag=1ISRReturnYYNNYNROAD0:ROAD1:Directionflag=05.9.101Sensor1Sensor0Light0Light15.9.1Sensor0high?Direction=0?Direction=1?ChangetoDirection0ChangetoDirection1ReturnDirectionflag=1ISRReturnYYNNYNROAD0:ROAD1:Directionflag=05.9.1ISRINT0: ;InterruptServiceRoutine CLR EA ;Disableinterrupts JNB SENSOR0,ROAD1ROAD0: JNB DIRN,RETURN;IsDirection=0? ACALLCHANGE_TO_0;Changelights CLR DIRN

;Direction=0? SJMPRETURNROAD1: JB DIRN,RETURN;IsDirection=1? ACALLCHANGE_TO_1;Changelights SETBDIRN ;Direction=1RETURN: SETBEA ;Enableinterruptsagain RETISUBROUTINEChangeto0Red0&Yellow1ONRed0andRed1ONGreen0andRed1ONReturnSUBROUTINEChangeto1Red1&Yellow0ONRed1andRed0ONGreen1andRed0ONReturn5.9.1CHANGE_TO_0:;Tochangedirectionoflightsto0

ACALL LIGHTS_OFF CLR RED0 ;ONRed0 CLR YELLOW1 ;ONYellow1

ACALL DELAY ACALL LIGHTS_OFF CLR RED0 ;ONRed0 CLR RED1 ;ONRed1

ACALL DELAY ACALL LIGHTS_OFF CLR GREEN0 ;ONGreen0 CLR RED1 ;ONRed1

ACALL DELAY RETCHANGE_TO_1:;Tochangedirectionoflightsto1

ACALL LIGHTS_OFF CLR RED1 ;ONRed1 CLR YELLOW0 ;ONYellow0

ACALL DELAY ACALL LIGHTS_OFF CLR RED1 ;ONRed1 CLR RED0 ;ONRed0

ACALL DELAY ACALL LIGHTS_OFF CLR GREEN1 ;ONGreen1 CLR RED0 ;ONRed0

ACALL DELAY RETLIGHTS_OFF: ;Toturnoffallthelights SETB RED0 SETB YELLOW0 SETB GREEN0 SETB RED1 SETB YELLOW1 SETB GREEN1 RET5.9.1Pleasetrythefollowing..Question5.10.11Page100Question5.10.11PushbuttontotoggleLED

LED_____ P1.0;LEDonP1.0 FLAG_____ 20h.4;Lightonflag ORG 0000h AJMP MAIN ORG ______ ;ISRforINT0 AJMP ISR_INT0MAIN: SETB EA SETB ____ ;Edgetrigger SETB EX0 ;EnableINT0 SETB FLAG ;Lighton SJMP $Question5.10.11PushbuttontotoggleLEDBITBIT0003hIT0ISR_INT0: ____ FLAG ;Complement MOV C,FLAG ____ LIGHT ;IfFlag=0,then ;turnLEDon ____ LED ;IfFlag=1,then ;turnLEDoff AJMP EXITLIGHT: CLR LED ;TurnonLEDEXIT: ____ ;ReturnQuestion5.10.11PushbuttontotoggleLEDCPLJNCSETBRET5.7Multiple-sourceinterruptsHowcanwereceivemanyexternalinterrupts?WeonlyhaveINT0andINT1Highforinterrupt00000Highforinterrupt101000Highforinterrupt01 ORG 0000h AJMP MAIN ORG 0003h ;ISRforINT0 AJMP ISR_INT0MAIN: ;Mainprogram

SJMP $5.7Multiple-sourceinterruptsISR_INT0: JB P1.1,ISR1 ;Polllines JB P1.2,ISR2 JB P1.3,ISR3 JB P1.4,ISR4 JB P1.5,ISR5ISR1: ;Interrupt1

RETIISR2: ;Interrupt2

RETIISR3: ;Interrupt3

RETI5.9.2RemotesensorwithswitchinterruptIfinterruptthenaveragelast10itemsonstack8051P0.7P0.0P1.0A-DThermometer11hF6h49hC6h2FhStackINT0P3.2+508051P0.7P0.0P1.0A-DThermo-meter11hF6h49hC6h2FhStackINT0P3.2+5025oC19h100000111119h

ORG0000h

MAIN:

SETBP1.0 NEXT:JNBP1.0,$;Wait JB P1.0,$ ;Wait PUSHP0 SJMPNEXT8051P0.7P0.0P1.0A-DThermo-meter11hF6h49hC6h2FhStackINT0P3.2+5025oC19h119h0Calculateaverageoftopten

TEMPEQU30h ORG0000h SJMPMAIN ORG0003h AJMPISR_INT0MAIN:SETBIT0 SETBEA SETBEX0 SETBP1.0 NEXT:JNBP1.0,$;Wait JB P1.0,$ ;Wait PUSHP0 SJMPNEXTISR_INT0: RETI?

TEMPEQU30h ORG0000h SJMPMAIN ORG0003h AJMPISR_INT0MAIN:SETBIT0 SETBEA SETBEX0 SETBP1.0 NEXT:JNBP1.0,$;Wait JB P1.0,$ ;Wait PUSHP0 SJMPNEXTISR_INT0: MOVR0,#0Ah POPAX: POPTEMP ADDA,T