[Jenifer]

Thank you very much sir……

sorry for the late reply

[Jenifer]

Dear sir,

 

         My problem is, i had stored some values in eeprom. while reading the stored values it shows some values which i was not stored in e2prom. can u please tell me where is the problem is and what alterations i have to do, to clear this bug.

 

Thanks in advance……..

[Jenifer]

Dear sir,

           I am using AT24c64 and AT89c52. the resistor value am using is 22k. Is that enough or i have to make some alterations in resistor value? if it so means please tell me the resistor value……  

 

Thanks in advance….

[Jenifer]

Hi Farrok…..

           thank you very much sorry for the late reply……….

 

[Jenifer]

Hi…

  please can any one help me…

I need to interface AT24c64 with 89c52. here is my asm code… i cannot write even 00h to eeprom.
please debug my code and guide me…

org 0000h

sjmp start

start:

mov p1,#0ffh   ; initializing port 1 as input

lcall none

sjmp start

none:ret

lcall write

lcall read

lcall none

;********** Write Routine*******

write:

mov r3,#00h     ; mem address high ; is the address in eeprom where data will start

mov r4,#00h     ;mem address low

mov r1,#00h     ; byte to be send to eeprom is stored in r1

lcall bytewr

ret

bytewr:

lcall eepstart        ; start to write

mov a,#0a0h   ; eeprom write command

lcall send

mov a,r3

lcall send

mov a,r4

lcall send

mov a,r1

lcall send

lcall stop         ;stop

ret



;********Transmission of data one by one********



send:

mov r2,#08h    ; data transmission for 8 bits

bck:

rlc a

jc bck1

clr p1.1               ;    if carry low clear data

setb p1.0

clr p1.0

djnz r2,bck

sjmp ack

bck1:

setb p1.1           ;if carry high set data

setb p1.0

clr p1.0

djnz r2,bck



;******** acknowledgement from eeprom*********

ack:                         ;ack from eeprom

setb p1.0

clr p1.0

ret

;*******read data routine********

read:

mov r3,#00h

mov r4,#00h

lcall byterd

mov r1,a

ret



byterd:

lcall eepstart              ; start to read

mov a,#0a0h

lcall send

mov a,r4

lcall send

lcall stop

lcall cread

ret



cread:

lcall eepstart

mov a,#0a1h             ;read command

lcall send

lcall recv

mov r1,a      ; store data

lcall stop        ; stop

ret

;**********receving data one by one********

recv:

mov r2,#08h

setb p1.1

rec:

clr p1.0

setb p1.0

clr c

jnb p1.1,rec1

cpl c

rec1:

rlc a

djnz r2,rec

clr p1.0

ret

;******** Start routine********

eepstart:

setb p1.1    ; high to low transistion of data with high clock

clr p1.0

setb p1.0

clr p1.1

clr p1.0

ret

; ***********Stop routine********

stop:

clr p1.1     ; low to high transistion of data with high clock

setb p1.0

setb p1.1

ret



end

Thanks in advance…

[Jenifer]

Hi farrok,

         

       please send your code… It will help me…

[Author]

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