BLDCMotorSpeedEstimationUsingPDCTimerModule1SpeedCalculationofBLDC1.1SummaryofBLDCSincecurrentBLDChassubstitutedtheelectricalcommutatorforthemechanicalone,iteliminatesthedisadvantagesofnoise,spark,electromagneticdisturbance,shortlifetime,etc.NowBLDCisprovidedwithadvantagesofsimplestructure,dependableoperationandeasymaintenanceasACmotordoes,aswellasadvantagesofhighefficient,noexcitationcostandfunctionalspeedregulationastraditionalDCmotordoes.Soitiswidelyusedinvariousfieldsofindustrialcontrolnow.1.2PDCModuleIntroductionSPMC75F2413Aprovidestwochannelsof16bitPDC(PhaseDetectionControl,PDC)timersusedforcapturefunctionandPWMoperation.ItalsosupportspositiondetectionfeaturesforBrushless-DCmotorapplication.ThePDCtimersareverysuitableforbothmechanicalspeedcalculation,withACIandBLDCmotorincluded,andphasecommutationforchangingcurrentconductionaccordingtopositioninformation.Figure1-1showstheblockdiagramofentirePDCtimers,channel0andchannel1.FordetailsofPDCtimer’sspecification,pleaserefertoTable1-1.Table1-1PDCTimerFunctionPDCTimer0PDCTimer1ClocksourcesInternalclock:FCK/1,FCK/4,FCK/16,FCK/64,FCK/256,FCK/1024Externalclock:TCLKA,TCLKBInternalclock:FCK/1,FCK/4,FCK/16,FCK/64,FCK/256,FCK/1024Externalclock:TCLKA,TCLKBIOpinsTIO0A,TIO0B,TIO0CTIO1A,TIO1B,TIO1CTimergeneralregisterP_TMR0_TGRA,P_TMR0_TGRB,P_TMR0_TGRCP_TMR1_TGRA,P_TMR1_TGRB,P_TMR1_TGRCTimerbufferregisterP_TMR0_TBRA,P_TMR0_TBRB,P_TMR0_TBRCP_TMR1_TBRA,P_TMR1_TBRB,P_TMR1_TBRCTimerperiodandcounterregisterP_TMR0_TPR,P_TMR0_TCNTP_TMR1_TPR,P_TMR1_TCNT1CapturesampleclockInternalclock:FCK/1,FCK/2,FCK/4,FCK/8Internalclock:FCK/1,FCK/2,FCK/4,FCK/8CountingedgeCountonrising,falling,bothedgeCountonrising,falling,bothedgeCounterclearsourceClearedonP_TMR0_TGRA,P_TMR0_TGRB,P_TMR0_TGRCcaptureinput.ClearedonP_POS0_DectDatapositiondetectiondatachanges.ClearedonP_TMR0_TPRcomparematches.ClearedonP_TMR1_TGRA,P_TMR1_TGRB,P_TMR1_TGRCcaptureinput.ClearedonP_POS1_DectDatapositiondetectiondatachanges.ClearedonP_TMR1_TPRcomparematches.InputcapturefunctionYesYesPWMcomparematchoutputfunction1outputYesYes0outputYesYesOutputHoldYesYesEdge-alignedPWMYesYesCenter-alignedPWMYesYesPhasecountingmodeYes,phaseinputsareTCLKA/TCLKBYes,phaseinputsareTCLKC/TCLKDTimerbufferoperationYesYesADconvertstarttriggerP_TMR0_TGRAcomparematchP_TMR1_TGRAcomparematchInterruptsourcesTimer0TPRinterruptTimer0TGRAinterruptTimer0TGRBinterruptTimer0TGRCinterruptTimer0PDCinterruptTimer0overflowinterruptTimer0underflowinterruptTimer1TPRinterruptTimer1TGRAinterruptTimer1TGRBinterruptTimer1TGRCinterruptTimer1PDCinterruptTimer1overflowinterruptTimer1underflowinterrupt2Figure1-1PDCTimersBlockDiagram1.3PDCOperationThisnotemainlydepictsPDCapplicationinmotorspeedmeasurement.FordetailedPDCintroduction,pleasereferto“SPMC75F2413AProgrammingGuide”authoredbySunplus.PDCmodulehasfourtypesofregisterstoperformspeedmeasurement:TimercontrolregisterP_TMRx_Ctrl(x=0,1),positiondetectioncontrolregisterP_POSx_DectCtrl(x=0,1),inputoutputcontrolregisterP_TMRx_IOCtrl(x=0,1),andtimerinterruptenableregisterP_TMRx_INT(x=0,1).Where,P_TMRx_CtrlandP_POSx_DectCtrlareintroducedindetail.1.31InputOutputControlRegisterP_TMRx_Ctrl(x=0,1)B15B14B13B12B11B10B9B8R/WR/WR/WR/WR/WR/WR/WR/W000000003SPCKMODECLEGSB7B6B5B4B3B2B1B0R/WR/WR/WR/WR/WR/WR/WR/W00000000SPCKMODECLEGSBit15:14SPCK:Captureinputsampleclockselect.Thesebitsselectthecapturein...
