讀寫24LCxx系列的EEPROM的實(shí)例程序讀寫24LCxx系列的EEPROM的實(shí)例程序;********************************************************

;*

*

;*

?PIC16F877A?I2CMaster家Α???﹃?ΑEEPROM?絛ㄒ祘Α

*

;*

*

;*Writtenby:

RichardYang

*

;*

Sr.CorporateApplicationEngineer

*

;*

MicrochipTechnologyInc.

*

;*Date:

Oct.2nd'2002

*

;*Revision:1.00

*

;********************************************************

;*************************************************

;ThissourcecodeprovidesademonstrationoftheMSSPperipheral

;onthePIC16F87xMCU.

;

;

;***********

ThesubroutinesforEEPROM

*****************

;

;EE_Random_Read

;EEPROMRandomaddressReadfromEEPROM

;EE_SEQU_Read

;EEPROMSequentialReadformEEPROM

;EE_Ack_Check

;PollingcurrentstatusofEEPROM

;EE_Page_Write

;PageWritefunctionforEEPROM

;EE_Byte_Write

;WriteabytetoEEPROMwithaddresssetting

;

;***********

ThesubroutinesforI2C

*****************

;

;Init_I2C_Master

;InitialI2CModuleforMasterMode,7-bitaddress

;StartI2C

;SendaSTARTCondition!!

;StopI2C

;SendsSTOPCondition

;RstartI2C

;SendaRepeatStartconditionaltoI2C

;Non_Ack

;SendaNon-acknowledgesignaltoI2C

;An_Ack

;SendaacknowledgesignaltoI2C

;Sebd_Byte

;SendabytetoI2Cbus

;RecI2C

;EnableReadabyteformslavedevice

;I2C_Done

:WaittheI2Ccompletedthecurrectprocess

;

;***************************************************

listp=16f877a

＃include;

;***************************************

;

﹚竡跑計(jì)?RAM???

;

CBLOCK0x20

I2C_Ctrl

I2C_Addr

I2C_Data

I2C_Page_Length

D_Count

ENDC

cblock0x40

I2C_Page_Buffer:8

I2C_SEQU_Buffer:8

endc

;

;***************************************

;

﹚竡い耞?既?竟??w_temp

EQU0x72

status_tempEQU0x73

pclath_tempEQU0x74

;

;***************************************

;

﹚竡I2C???の竲?

;

EEPROM_CMDequ0xA0

;DeviceadressofSlavePoint

EE_Read

equ.1

EE_Writeequ.0;

#define

SCLPORTC,3

;I2CSCLpin

#define

SDAPORTC,4

;I2CSDApin;;********************************************

;Locatesstartupcode@theresetvector

;********************************************

Reset_Addr

org

0x00

nop

gotoMain_Init

;

org

0x04

gotoISR

;

;*************************************************************

;****TheStartAddressofISRis0x004

;****"PUSH"&"POP"?ㄏノ絛ㄒ:続ノ?鉤PIC16F877ΤSHAREBANK?PIC

;**************************************************************

ISR

Push

movwf

w_temp

;saveoffcurrentWregistercontents

movfSTATUS,w

;movestatusregisterintoWregister

movwfstatus_temp

;saveoffcontentsofSTATUSregister

movfPCLATH,W

movwfpclath_temp

;

;

Putyourinterruptcodehere

;

Pop

movfpclath_temp,W

movwfPCLATH

movf

status_temp,w

;retrievecopyofSTATUSregister

movwfSTATUS

;restorepre-isrSTATUSregistercontents

swapf

w_temp,f

swapf

w_temp,w

;restorepre-isrWregistercontents

;

retfie

;returnfrominterrupt

;Main_Init

pageselInit_I2C_Master

;SetPAGEtoPCLATHRegister

call

Init_I2C_Master

;InittheMSSPforI2CMaster

;

bankselI2C_Ctrl

movlwEEPROM_CMD

;LoadEEPROMcommandaddress@0xA0

movwfI2C_Ctrl

;

;

Main

;

;

;

;*???代剛祘Α穦?盢?艙計(jì)?(0x40-0x47)糶??RMA0x40-0x47??竚

;*?ノPageWrite?よΑ盢8??じ艙?戈?糶?EEPROM?

;*秈︽?篈?盎代EEPROM琌??ЧΘ糶??笆??程?盢?糶

;*??戈??SequentialRead?よΑ眖EEPROM弄?ㄓ??I2C_SEQU_Bufferい

;Test_Page_RW

movlw0x08

movwfI2C_Page_Length

movlwI2C_Page_Buffer

_Fill_RAMmovwfFSR

movwfINDF

incfFSR,W

decfszI2C_Page_Length,F

goto_Fill_RAM

;

Test_Page_Write

;

bankselI2C_Ctrl

movlwEEPROM_CMD

;LoadEEPROMcommandaddress@0xA0

movwfI2C_Ctrl

movlw0x10

;SelectEEPROMlocationat0x00

movwfI2C_Addr

movlw.8

movwfI2C_Page_Length

callEE_Page_Write

;

callEE_Ack_Check

;

bankselI2C_Ctrl

movlwEEPROM_CMD

;LoadEEPROMcommandaddress@0xA0

movwfI2C_Ctrl

movlw0x10

movwfI2C_Addr

movlw.8

movwfI2C_Page_Length

callEE_SEQU_Read

;

goto$

;

;

;

;*???代剛祘Α穦?糶????じ艙?戈?糶?EEPROMい

;*?秈︽?篈?盎代琌??ЧΘ糶??笆??程?盢?糶

;*??戈??眖EEPROM弄?ㄓ??I2C_Data既?竟い

;

Test_1byte_RW

bankselI2C_Ctrl

movlwEEPROM_CMD

;LoadEEPROMcommandaddress@0xA0

movwfI2C_Ctrl

movlw0x00

;SelectEEPROMlocationat0x00

movwfI2C_Addr

movlw0xAA

;Writedata0x5Atolocation0x00ofEEPROM

movwfI2C_Data

callEE_Byte_Write

;

Test2

callEE_Ack_Check

;PollingAcknowledgefornextaccess

;

bankselI2C_Data

movlw0x00

;ClearI2Cdatabuffer

movwfI2C_Data

;

Test3

bankselI2C_Ctrl

movlwEEPROM_CMD

;LoadEEPROMcommandaddress@0xA0

movwfI2C_Ctrl

movlw0x00

movwfI2C_Addr

callEE_Random_Read

;

goto

$

;;

;******************************************************

;*

RandomReadaBytefromEEPROM

;*

;*Input:

;*

-I2C_Ctrl:ControlByteofEEPROM

;*

-I2C_Addr:LocationofEEPROM

;*Output:

;*

-I2C_Data:ReadDatafromEEPROM

;******************************************************

;

;SendCommandforRANDOMREAD:

;"Start+0xA0+EE_Address+ReStart+0xA1+Read_Data+NAck+Stop"

;EE_Random_Read

callStartI2C

;SetSSPCON2.SEN

;

bcf

I2C_Ctrl,0

;setforwriteCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

;

movfI2C_Addr,W

;SendouttheRendomaddressofEEPROM

callSend_Byte

;

callRstartI2C

;SendaRepeatStarttoI2C

;

bsf

I2C_Ctrl,0

;setforReadCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

;

callRecI2C

;EnableI2CReceive

;

BANKSELSSPBUF

movfSSPBUF,W;SavetoI2C_DataFirst!!

movwfI2C_Data

callNon_Ack

;InitialNACKResponse!!

callStopI2C

;InitialSTOPCondition

return

;

;***************************************************************

;*

SequentialReadfromEEPROM

;*

;*Input:

;*

-I2C_Ctrl:ControlByteofEEPROM

;*

-I2C_Addr:StartLocationofEEPROM

;*

-I2C_Page_Length:Howmanybyteneedtoread

;*Output:

;*

-I2C_SEQU_Buffer:SequentialReadDatabuffer

;*

;***************************************************************

;

;SendCommandforRANDOMREAD:

;"Start+0xA0+EE_Address+ReStart+0xA1+Read_Data+NAck+Stop"

;

EE_SEQU_Read

callStartI2C

;SetSSPCON2.SEN

;

bcf

I2C_Ctrl,0

;setforwriteCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

;

movfI2C_Addr,W

;SendouttheRendomaddressofEEPROM

callSend_Byte

;

callRstartI2C

;SendaRepeatStarttoI2C

;

bsf

I2C_Ctrl,0

;setforReadCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

;

movlwI2C_SEQU_Buffer

movwfFSR

;

_Sequ_LoopcallRecI2C

;EnableI2CReceive

BANKSELSSPBUF

movfSSPBUF,W

;SavetoI2C_DataFirst!!

movwfINDF

incfFSR,F

decfszI2C_Page_Length,F

goto_Cont_Read

goto_End_Read

_Cont_ReadcallAn_Ack

goto_Sequ_Loop

;

_End_ReadcallNon_Ack

;InitialNACKResponse!!

callStopI2C

;InitialSTOPCondition

return

;

;******************************************************

;*

EEPROMAcknowledgePolling

;*

;*

--

TheroutinewillpollingtheACK

;*

responsefromEEPROM

;*

--

ACK=0return

;*

--

ACK=1sendRestart&loopcheck

;*

;******************************************************

;

EE_Ack_Check

callStartI2C

;SetSSPCON2.SEN

bcf

I2C_Ctrl,0

;ClearforWriteCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

_Ack_Polling

BANKSELSSPCON2

btfssSSPCON2,ACKSTAT;CheckACKSTATbit,0=ACK,1=NACK

gotoACK_Return

;Ack=0;EEPROMisReady

_Ack_Hi

;Ack=1;EEPROMisBusyforWrite

callDelay_mS

;Delay500uSfornextAckpolling

callRstartI2C

;SendaRepeatStarttoI2C

bcf

I2C_Ctrl,0

;ClearforWriteCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

goto_Ack_Polling

ACK_Return

callStopI2C

;InitialSTOPCondition

return

;

;**********************************************************

;*

PageWrite1to8BytestoEEPROM

;*

;*

Input:

;*

-I2C_Ctrl:ControlByteofEEPROM

;*

-I2C_Addr:LocationofEEPROM

;*

-I2C_Page_Buffer:RAMlocationofData

;*

-I2C_Page_Length:Datalengthcount

;*

;**********************************************************

;

;SendCommandforPAGEWRITE:

;"Start+0xA0+EE_Address+W_Data0+..+W_DataN+Stop"

;

EE_Page_Write

movfI2C_Page_Length,W

btfscSTATUS,Z

return

;

callStartI2C

;SetSSPCON2.SEN

;

bcf

I2C_Ctrl,0

;ClearforWriteCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

;

movfI2C_Addr,W

;SendouttheCommand

callSend_Byte

;

movlwI2C_Page_Buffer

movwfFSR

_W1

movfINDF,W

callSend_Byte

incfFSR,F

decfszI2C_Page_Length,F

goto_W1

;

callStopI2C

;InitialSTOPCondition

return

;

;

;*******************************************************

;*

WriteaBytetoEEPROM

;*

;*Input:

;*

-I2C_Ctrl:ControlByteofEEPROM

;*

-I2C_Addr:LocationofEEPROM

;*

-I2C_Data:DatatoEEPROM

;*

;*******************************************************

;

;SendCommandforBYTEWRITE:

;"Start+0xA0+EE_Address+Write_Data+Stop"

;

EE_Byte_Write

callStartI2C

;SetSSPCON2.SEN

;

bcf

I2C_Ctrl,0

;ClearforWriteCommand

movfI2C_Ctrl,W

;SendSlaveAddresstoI2CBus

callSend_Byte

;

movfI2C_Addr,W

;SendouttheCommand

callSend_Byte

;

movfI2C_Data,W

;SendouttheData

callSend_Byte

;

callStopI2C

;InitialSTOPCondition

return

;

;**********************************************************************

;

;

AsfollowingsubroutinesperformcommonlyusedI2Cfunctions.

;

YoucanusethesesubroutinesforyourI2Caccess

;

;**********************************************************************

;

;***InitialI2Cmodulefot7-bitI2CMasterModewith100Kcps@4MHz

;

Init_I2C_Master

BANKSELTRISC

;InitialPortC,bit3&4asInput

bsf

SCL

;RC3=SCL

,

RC4=SDA

bsf

SDA

;

BANKSELPORTC

bsf

SCL

;SCL=Hi

bsf

SDA

;SDA=Hi

;

movlwb'00101000'

;I2CMasterMode,ClockRate:FOSC/(4*SSPADD+1)

movwfSSPCON

;

;

bankselSSPADD

movlw

.9

;Thisgives100KHzI2Cclock@4MHz

movwf

SSPADD

;(4MHz/4)/(9+1)=100KHz

;

movlw

b'10000000'

;Disableslewratecontrol,

movwf

SSPSTAT

;andclearstatusbits

;

movlw

b'00000000'

;SetSCL,SDAintoReadystatus

movwf

SSPCON2

;

return

;

;******

SendSTARTconditiontobus

*******

;

StartI2C

;InitiatetheI2CSTARTcondition.

bankselSSPCON2

bsf

SSPCON2,SEN

gotoI2C_Done

;

;******

SendSTOPconditiontobus

*******

;

StopI2C

bankselSSPCON2

bsf

SSPCON2,PEN

gotoI2C_Done

;

;******

SendRESTARTconditiontobus