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Time-BaseSubmoduleRegisters
Table4-4.Time-BaseControlRegister(TBCTL)FieldDescriptions(continued)
BitFieldValueDescription
6SWFSYNCSoftwareForcedSynchronizationPulse
0Writinga0hasnoeffectandreadsalwaysreturna0.
1Writinga1forcesaone-timesynchronizationpulsetobegenerated.
ThiseventisORedwiththeEPWMxSYNCIinputoftheePWMmodule.
SWFSYNCisvalid(operates)onlywhenEPWMxSYNCIisselectedbySYNCOSEL=00.
5:4SYNCOSELSynchronizationOutputSelect.ThesebitsselectthesourceoftheEPWMxSYNCOsignal.
00EPWMxSYNC:
01CTR=zero:Time-basecounterequaltozero(TBCTR=0x0000)
10CTR=CMPB:Time-basecounterequaltocounter-compareB(TBCTR=CMPB)
11DisableEPWMxSYNCOsignal
3PRDLDActivePeriodRegisterLoadFromShadowRegisterSelect
0Theperiodregister(TBPRD)isloadedfromitsshadowregisterwhenthetime-basecounter,
TBCTR,isequaltozero.
AwriteorreadtotheTBPRDregisteraccessestheshadowregister.
1LoadtheTBPRDregisterimmediatelywithoutusingashadowregister.
AwriteorreadtotheTBPRDregisterdirectlyaccessestheactiveregister.
2PHSENCounterRegisterLoadFromPhaseRegisterEnable
0Donotloadthetime-basecounter(TBCTR)fromthetime-basephaseregister(TBPHS)
1Loadthetime-basecounterwiththephaseregisterwhenanEPWMxSYNCIinputsignaloccursor
whenasoftwaresynchronizationisforcedbytheSWFSYNCbit.
1:0CTRMODECounterMode
Thetime-basecountermodeisnormallyconfiguredonceandnotchangedduringnormaloperation.
Ifyouchangethemodeofthecounter,thechangewilltakeeffectatthenextTBCLKedgeandthe
currentcountervalueshallincrementordecrementfromthevaluebeforethemodechange.
Thesebitssetthetime-basecountermodeofoperationasfollows:
00Up-countmode
01Down-countmode
10Up-down-countmode
11Stop-freezecounteroperation(defaultonreset)
Registers96SPRU791D–November2004–RevisedOctober2007
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