 |
поискавой системы для электроныых деталей |
|
|
поискавой системы для электроныых деталей |
|
HT45F3W датащи(PDF) 43 Page - Holtek Semiconductor Inc |
|
|
|||||||||||||||||||||||||||||
HT45F3W датащи(HTML) 43 Page - Holtek Semiconductor Inc |
|
|
43 / 167 page  Rev. 1.50 4� De�e��e� 01� �01� Rev. 1.50 43 De�e��e� 01� �01� HT45F3W R-Type Blood Pressure Meter Flash MCU HT45F3W R-Type Blood Pressure Meter Flash MCU Reading Data from the EEPROM ToreaddatafromtheEEPROM,thereadenablebit,RDEN,intheEECregistermustfirstbeset hightoenablethereadfunction.TheEEPROMaddressofthedatatobereadmustthenbeplaced intheEEAregister.IftheRDbitintheEECregisterisnowsethigh,areadcyclewillbeinitiated. SettingtheRDbithighwillnotinitiateareadoperationiftheRDENbithasnotbeenset.When thereadcycleterminates,theRDbitwillbeautomaticallyclearedtozero,afterwhichthedatacan bereadfromtheEEDregister.ThedatawillremainintheEEDregisteruntilanotherreadorwrite operationisexecuted.TheapplicationprogramcanpolltheRDbittodeterminewhenthedatais validforreading. Writing Data to the EEPROM TowritedatatotheEEPROM,theEEPROMaddressofthedatatobewrittenmustfirstbeplaced intheEEAregisterandthedataplacedintheEEDregister.Thenthewriteenablebit,WREN, intheEECregistermustfirstbesethightoenablethewritefunction.Afterthis,theWRbitin theEECregistermustbeimmediatelysethightoinitiateawritecycle.Thesetwoinstructions mustbeexecutedconsecutively.TheglobalinterruptbitEMIshouldalsofirstbeclearedbefore implementinganywriteoperations,andthensetagainafterthewritecyclehasstarted.Notethat settingtheWRbithighwillnotinitiateawritecycleiftheWRENbithasnotbeenset.Asthe EEPROMwritecycleiscontrolledusinganinternaltimerwhoseoperationisasynchronousto microcontrollersystemclock,acertaintimewillelapsebeforethedatawillhavebeenwritteninto theEEPROM.Detectingwhenthewritecyclehasfinishedcanbeimplementedeitherbypollingthe WRbitintheEECregisterorbyusingtheEEPROMinterrupt.Whenthewritecycleterminates, theWRbitwillbeautomaticallyclearedtozerobythemicrocontroller,informingtheuserthatthe datahasbeenwrittentotheEEPROM.TheapplicationprogramcanthereforepolltheWRbitto determinewhenthewritecyclehasended. Write Protection Protectionagainstinadvertentwriteoperationisprovidedinseveralways.Afterthedeviceis powered-ontheWriteEnablebitinthecontrolregisterwillbeclearedpreventinganywrite operations.Alsoatpower-ontheBankPointer,BP,willberesettozero,whichmeansthatData MemoryBank0willbeselected.AstheEEPROMcontrolregisterislocatedinBank1,thisaddsa furthermeasureofprotectionagainstspuriouswriteoperations.Duringnormalprogramoperation, ensuringthattheWriteEnablebitinthecontrolregisterisclearedwillsafeguardagainstincorrect writeoperations. EEPROM Interrupt TheEEPROMwriteinterruptisgeneratedwhenanEEPROMwritecyclehasended.TheEEPROM interruptmustfirstbeenabledbysettingtheDEEbitintherelevantinterruptregister.Howeveras theEEPROMiscontainedwithinaMulti-functionInterrupt,theassociatedmulti-functioninterrupt enablebitmustalsobeset.WhenanEEPROMwritecycleends,theDEFrequestflagandits associatedmulti-functioninterruptrequestflagwillbothbeset.Iftheglobal,EEPROMandMulti- functioninterruptsareenabledandthestackisnotfull,ajumptotheassociatedMulti-function Interruptvectorwilltakeplace.WhentheinterruptisservicedonlytheMulti-functioninterruptflag willbeautomaticallyreset,theEEPROMinterruptflagmustbemanuallyresetbytheapplication program.MoredetailscanbeobtainedintheInterruptsection. |
|
ссылки URL |
| Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | Ссылка на техническое описание | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Russian ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
