EEPROM test code problem.

This simple code is test the write and read of EEPROM.







Firstly the LED at P1 will have all LED on, after a sec, have the P1 will have LED on.



Next, code is to write 01010101B into the EEPROM.



CJNE will check to see if it is written.



But, after comparing, the data isn't similar and the code is restarted.







If the writing process works the LED at P1.0 should be the only LED on, which will notify the success of writing into the EEPROM.







The next portion of the code will recall/read the written data in the EEPROM.



f it is able to read, P1 will have alternate LED on and off.



Please provide solutions, sources and why or what I had done wrong, to educate me. Thank you.



=============================



org 0

jmp start

eecon EQU 96h



start:

MOV A,#11111111B

MOV P1,A

ACALL DELAY0

MOV A,#00001111B

MOV P1,A

ACALL DELAY0



WRITE:

MOV EECON,#00001000b



mov dptr,#0 ;point to the memory location needed to write to. chosen location 0

mov a,#10101010B ;move the data (0fch) to Accumulator

movx @dptr,a ;write the data to the chosen location



MOVX A, @DPTR

CJNE A, #10101010B, START



WRITEFIN:

MOV A,#00000001B

MOV P1,A

ACALL DELAY0

READ:

MOV EECON,#00001000b

mov DPTR,#0 ;point to the memory location needed to read from. Chosen location 0

movx A,@dptr ;move the data within the memory location to the Accumulator

mov R0,A ;move the data within Accumulator to the Register



WAT: MOV P1,R0

SJMP WAT



;========================================

DELAY0:

ACALL DELAY

ACALL DELAY

ACALL DELAY

ACALL DELAY

ACALL DELAY

RET

DELAY:

MOV R3, #255

HERE2:

MOV R4, #255

HERE:

DJNZ R4, HERE

DJNZ R3, HERE2

RET

end