Read, Write EEPROM problem on AT89S8253

[Nexus]

 

My project is meant to  enable the User to toggle "LIKE" or "DISLIKE" and save their preferance in the EEPROM. 

 

The data to represent "LIKE" is 0101 0101B.

The data to represent "DISLIKE" is 1010 1010B.

So, when the user toggles their choice, the instruction, "RR A" should rotate the values within the Accumulator and the data should be the opposite now, thus displaying the other choice.

Firstly, the toggling isn't working. I have no idea why, this simple instruction should display the other choice, but it keeps displaying "DISLIKE".

 

Next, I am not sure if the data need to be written/read in the EEPROM is working or right.

 

Please do help me. Do not refer me to online materials, I have been searching online for the past few weeks. Please do provide me the solution and try to explain to me. I really keen in learning how and why it works. Thank you.

 

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CSEG AT 0000H

LJMP STARTUP

 

CSEG AT 0003H

LJMP EXT_0

 

CSEG AT 000BH

LJMP TIMER_0

 

CSEG AT 0013H

LJMP EXT_1

 

CSEG AT 001BH

LJMP TIMER_1

 

CSEG AT 0036H

SETB P1.3 ; LEFT

SETB P1.4 ; UP (BACK BUTTON)

SETB P1.5 ; CENTER (LIKE/DISLIKE BUTTON)

SETB P1.6 ; RIGHT

SETB P1.7 ; DOWN (ENTER BUTTON)

 

 

EECON EQU 96H

 

STARTUP:

MOV A,#38H

ACALL COMNWRT

MOV A, #0EH

ACALL COMNWRT

MOV A, #01

ACALL COMNWRT

MOV A, #06H

ACALL COMNWRT

MOV A, #84H ;TO WRITE ON TOP LINE

ACALL COMNWRT

MOV A, #'H'

ACALL DATAWRT

MOV A, #'E'

ACALL DATAWRT

MOV A, #'L'

ACALL DATAWRT

MOV A, #'L'

ACALL DATAWRT

MOV A, #'O'

ACALL DATAWRT

SJMP ENTER2START

 

;OPTIONAL SUBROUTINES

ENTER2START:

MOV A, #0C1H ;TO WRITE ON BOTTOM LINE

ACALL COMNWRT

MOV A, #'E'

ACALL DATAWRT

MOV A, #'N'

ACALL DATAWRT

MOV A, #'T'

ACALL DATAWRT

MOV A, #'E'

ACALL DATAWRT

MOV A, #'R'

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #'T'

ACALL DATAWRT

MOV A, #'O'

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #'S'

ACALL DATAWRT

MOV A, #'T'

ACALL DATAWRT

MOV A, #'A'

ACALL DATAWRT

MOV A, #'R'

ACALL DATAWRT

MOV A, #'T'

ACALL DATAWRT

WAIT4USER: ;waits for physical input

JNB P1.7, SP1

SJMP WAIT4USER

 

 

SP1:

ACALL CLEARDISP

MOV A, #80H ;TO WRITE ON TOP LINE

ACALL COMNWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #'S'

ACALL DATAWRT

MOV A, #'O'

ACALL DATAWRT

MOV A, #'C'

ACALL DATAWRT

MOV A, #'C'

ACALL DATAWRT

MOV A, #'E'

ACALL DATAWRT

MOV A, #'R'

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #'-'

ACALL DATAWRT

MOV A, #'-'

ACALL DATAWRT

MOV A, #'>'

ACALL DATAWRT

ACALL READSAVEDPREF

 

 

SP1WAIT: ;waits for physical input

JNB P1.6, SP1SP2 ;RIGHT BUTTON

JNB P1.4, SP1C1 ;UP BUTTON (BACK)

JNB P1.5, SP1LIKE ;CENTER BUTTON (LIKE/DISLIKE BUTTON)

ACALL SP1WAIT

SP1SP2: SJMP SP1

SP1C1: SJMP SP1WAIT

SP1LIKE:LJMP TOGGLEPREF

 

;COMMON SUBROUTINES

 

CLEARDISP:

MOV A, #01H

ACALL COMNWRT

RET

 

COMNWRT: ;WITH DOUBLE DELAY

MOV P2, A

CLR P3.2

CLR P3.3

SETB P3.4

ACALL DELAY

CLR P3.4

ACALL DELAY

RET

 

DATAWRT: ;FOLLOWS UP WITH DELAY

MOV P2, A

SETB P3.2

CLR P3.3

SETB P3.4

ACALL DELAY

CLR P3.4

DELAY:

MOV R3, #50

HERE2:

MOV R4, #255

HERE:

DJNZ R4, HERE

DJNZ R3, HERE2

RET

 

 

READSAVEDPREF:

 

ORL EECON,#00001000b

mov DPTR,#10H ;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

XRL EECON,#00000000B

 

COMPARE:CJNE A, #01010101B, DISLIKE ;CHG DATA TO THE DATA TO BE COMPARED

ACALL LIKE

 

 

TOGGLEPREF: ;ROTATES THE BINARY TO THE LEFT AND COMPARES.

 

ORL EECON,#00001000b

mov DPTR,#10H ;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

XRL EECON,#00000000B ;move the data within Accumulator to the Register

RR A

CJNE A, #01010101B, DISLIKE ;COMPARES WITH LIKE, IF COMPARISON ISN'T LIKE, WILL JUMP TO DISLIKE.

SJMP LIKE

 

DISLIKE:

 

ORL EECON,#00001000b

ORL EECON,#00010000B

 

mov dptr,#10H ;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

 

XRL EECON, #00010000B

XRL EECON, #00000000B

 

MOV A, #0C5H ;TO WRITE ON BOTTOM LINE

ACALL COMNWRT

MOV A, #'D'

ACALL DATAWRT

MOV A, #'I'

ACALL DATAWRT

MOV A, #'S'

ACALL DATAWRT

MOV A, #'L'

ACALL DATAWRT

MOV A, #'I'

ACALL DATAWRT

MOV A, #'K'

ACALL DATAWRT

MOV A, #'E'

ACALL DATAWRT

LJMP SP1WAIT

 

LIKE:

 

 

ORL EECON,#00001000b

ORL EECON,#00010000B

 

mov dptr,#10H ;point to the memory location needed to write to. chosen location 0

mov a,#01010101B ;move the data (0fch) to Accumulator

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

 

XRL EECON, #00010000B

XRL EECON, #00000000B

 

MOV A, #0C5H ;TO WRITE ON BOTTOM LINE

ACALL COMNWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #'L'

ACALL DATAWRT

MOV A, #'I'

ACALL DATAWRT

MOV A, #'K'

ACALL DATAWRT

MOV A, #'E'

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

MOV A, #' '

ACALL DATAWRT

LJMP SP1WAIT

 

;INTERRUPT ROUTINES

 

EXT_0:

 

RETI

 

EXT_1:

 

RETI

 

TIMER_0:

 

RETI

 

TIMER_1:

 

RETI

 

END

 

 

[Ashutosh Bhatt]

on which EEPROM you are storing user preferences? r u using serial EEPROM?

[Author]

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