双语教学双语教学5.doc

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1、Ch5   Time and InterruptlKeywords：定时器（Timer） 中断（Interrupt）计数器（counter）定时器工作方式寄存器（TMOD，Timer mode）定时器控制寄存器（TCON，Timercontrol）启动定时器（TR，TimerRun）定时器满标志位（TF，TimeFull）中断允许寄存器（IE，InterruptEnable）中断优先权寄存器（InterruptPriority）lIntroduction:（Ⅰ）Timers/Counters:    80

2、31hastwo16bitTimers/Counterscapableofworkingindifferentmodes.Eachconsistsofa‘high’byteanda‘low’bytewhichcanbeaccessedundersoftware.Thereisamodecontrolregisterandacontrolregistertoconfigurethesetimers/countersinnumberofways.                                

3、                      Thesetimerscanbeusedtomeasuretimeintervals,determinepulsewidthsorinitiateeventswithonemicrosecondresolutionuptoamaximumof65millisecond(correspondingto65,536counts).Usesoftwaretogetlongerdelays.Workingascounter,theycanaccumulateoccurr

4、encesofexternalevents(fromDCto500KHz)with16bitprecision.（Ⅱ）Interrupts:    The8031hasfiveinterruptsources:onefromtheserialportwhenatransmissionorreceptionoperationisexecuted;twofromthetimerswhenoverflowoccursandtwocomefromthetwoinputpinsINT0,INT1.Eachinter

5、ruptmaybeindependentlyenabledordisabledtoallowpollingonsamesourcesandeachmaybeclassifiedashighorlowpriority.    Ahighprioritysourcecanoverridealowpriorityserviceroutine.Theseoptionsareselectedbyinterruptenableandprioritycontrolregisters,IEandIP.    Whenan

6、interruptisactivated,thentheprogramflowcompletestheexecutionofthecurrentinstructionandjumpstoaparticularprogramlocationwhereitfindstheinterruptserviceroutine.Afterfinishingtheinterruptserviceroutine,theprogramflowsreturntobacktotheoriginalplace.          

7、                           TheProgramMemoryaddress,0003Hisallottedtothefirstinterruptandnextsevenbytescanbeusedtodoanytaskassociatedwiththatinterrupt.InterruptSource                 ServiceroutinestartingaddressExternal0                           0003HTim

8、er/Counter0                  000BHExternal1                            0013HTimer/counter1                  001BHSerialport                          0023HlQuestions:ⅰHowmanyTimers/CountersdoestheSingleChipMicrocompu