atmel公司24系列eeprom编程举例

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1、ATMEL公司24系列EEPROM编程举例作者：尘封往事文章来源：本站原创点击数：2043更新时间：2006-1-1213:07:34NAME Control_AT24Cxx;ThiscollectionofroutinesallowsanAT89C2051microcontrollertoread;andwritetheAT24CxxfamilyofserialCMOSEEPROMS.Thisversionofthe;codeiscompatibleonlywiththeAT89C2051duetothelocationofthe;databufferandstacki

2、nRAM.Thecodemaybemodifiedtoworkwiththe;AT89C1051byrelocatingorresizingthebufferandstacktofitintothe;smalleramountofRAMavailableintheAT89C1051.Notethattheminimum;sizeofthebufferisdeterminedbythepagesizeoftheAT24Cxx.;;AllfiveAT24Cxxdeviceoperationsaresupported.ByteWrite,Current;AddressReada

3、ndRandomReadareimplementedbythefunctionsWRITE_BYTE,;READ_CURRENTandREAD_RANDOM,respectively.PageWriteandSequentialRead;arespecialcasesoffunctionsWRITE_BLOCKandREAD_BLOCK,respectively.;WRITE_BLOCKandREAD_BLOCKprocessfromonebytetothenumberofbytes;inapageandtransferdatabetweentheAT24Cxxandth

4、eRAMbuffer.;;ThecodesupportsmultipleAT24Cxxdevicesperbus,eachwithaunique;addressdeterminedbythewiringoftheaddresspins(A0,A1,A2).The;three-bitprogrammableaddressispassedtotheWRITE_BYTE,READ_CURRENT,;READ_RANDOM,WRITE_BLOCKandREAD_BLOCKfunctions,whereitiscombined;withtheAT24Cxxfixedaddress(

5、FADDR)andusedtoaddressadeviceonthe;bus.RefertotheAT24Cxxfamilydatasheetsforadditionalinformationon;deviceaddressing.;;FunctionsBYTE_FILL,VERIFY_BYTE_FILL,PAGE_FILLandVERIFY_PAGE_FILLare;artifactsfromthedebugprocessandservetoillustratetheuseofthe;devicereadandwritefunctionswithanAT24C64.To

6、modifythecodefora;differentmemberoftheAT24Cxxfamily,simplyredefinethevaluesofSIZE;(thenumberofbytesperdevice)andPSIZE(thenumberofbytesperpage).;Tochangethefillvalue,redefineFILL.Tochangetheprogrammableportion;ofthedeviceaddress,redefinePADDRtoavaluefromzerotoseven.;;ThecodemeetsallAT24Cxx

7、familytimingrequirementswhenexecutedbyan;AT89Cx051microcontrollerwitha12MHzclock.Codemodificationsmaybe;requiredifafasterclockissubstituted.FADDR  EQU 0a0h  ;fixedaddressforAT24CxxEEPROMsPADDR  EQU 0  ;programmableaddress(0..7)SIZE  EQU 2000h  ;bytesperAT24C64PSIZE