HT66F0187 datasheet(37/192 Pages) HOLTEK

37 / 192 page

Rev. 1.20

��st 2�� 201�

Rev. 1.20

3�

��st 2�� 201�

HT66F0187

A/D Flash MCU with EEPROM

HT66F0187

A/D Flash MCU with EEPROM

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

poweredon,theWriteEnablebitinthecontrolregisterwillbeclearedpreventinganywrite

operations.Alsoatpower-ontheMemoryPointerhighbyteregisters,MP1HandMP2H,willbe

resettozero,whichmeansthatDataMemorySector0willbeselected.AstheEEPROMcontrol

registerislocatedinSector1,thisaddsafurthermeasureofprotectionagainstspuriouswrite

operations.Duringnormalprogramoperation,ensuringthattheWriteEnablebitinthecontrol

registerisclearedwillsafeguardagainstincorrectwriteoperations.

EEPROM Interrupt

TheEEPROMwriteinterruptisgeneratedwhenanEEPROMwritecyclehasended.TheEEPROM

interruptmustfirstbeenabledbysettingtheDEEbitintherelevantinterruptregister.However,as

theEEPROMiscontainedwithinaMulti-functionInterrupt,theassociatedmulti-functioninterrupt

enablebitmustalsobeset.WhenanEEPROMwritecycleends,theDEFrequestflagandits

associatedmulti-functioninterruptrequestflagwillbothbeset.Iftheglobal,EEPROMandMulti-

functioninterruptsareenabledandthestackisnotfull,ajumptotheassociatedMulti-function

Interruptvectorwilltakeplace.WhentheinterruptisservicedonlytheMulti-functioninterruptflag

willbeautomaticallyreset,theEEPROMinterruptflagmustbemanuallyresetbytheapplication

program.

HT66F0187 bảng dữ liệu(PDF) 37 Page - Holtek Semiconductor Inc

HT66F0187 bảng dữ liệu(HTML) 37 Page - Holtek Semiconductor Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

bảng dữ liệu tải về

Link URL