Hello! I need help to program a clock that counts down from two minutes to zero. I've done a code in Keil, it should be so here 2:00 with three 7-segment displays. Here is the code that I have done:
START EQU P3.1
RESET EQU P3.0

DISA EQU P3.3
DISB EQU P3.2
DISC EQU P3.6
ORG 0000H
LJMP MAIN
ORG 0060H
MAIN:
JB START,$ ;WAIT FOR START BUTTON TO BE PRESSED
SETB DISA
SETB DISB
SETB DISC
DD1:SETB DISA
MOV A,#02H ;SETTING FOR MINUTE
MOV R1,A
DS1:MOV P0,R1
DD2:MOV A,#00H
MOV A,#05H
DS2:MOV P2,A
DD3:MOV A,#00H
MOV P0,R1
MOV A,#09H
DS3:MOV P1,A
LCALL DELAY
DEC A
CJNE A,#00H,DS3
MOV A,P2
MOV P1,#00H
ACALL DELAY
DEC A
CJNE A,#00H,DS2
TEN:MOV P2,#00H
MOV R6,#09H
TE:MOV P1,R6
DEC R6
ACALL DELAY
CJNE R6,#00H,TE
MOV P1,#00H
DEC R1
ACALL DELAY
MOV P0,R1
CJNE R1,#00H,DS1
MOV P0,#00H
LASTMIN:
DE2:MOV A,#05H
DF2:MOV P2,A
DE3:MOV A,#09H
DF3:MOV P1,A
LCALL DELAY
DEC A
CJNE A,#00H,DF3
MOV A,P2
MOV P1,#00H
ACALL DELAY
DEC A
CJNE A,#00H,DF2
LASTEN:
MOV P0,#00H
MOV P2,#00H
MOV R6,#09H
TE1:MOV P1,R6
DEC R6
ACALL DELAY
CJNE R6,#00H,TE1
MOV P1,#00H

RST: ;CLEARS ALL DISPLAYS AND RETURNS TO START
JB RESET,$
CLR DISA
CLR DISB
CLR DISC
JMP MAIN
DELAY: ;DELAY OF ONE SECOND
MOV TMOD,#01H
MOV TH0,#3CH
MOV TL0,#0B0H
MOV R7,#00H
SETB TR0
DEL:JNB TF0,DEL
MOV TH0,#3CH
MOV TL0,#0B0H
CLR TF0
INC R7
CJNE R7,#14H,DEL
RET
END

I'm really grateful if anyone can help me, I've been doing this for several hours, days and nothing works.

 

You might want to post this in "Programmers Corner" on this site.
I'll tell the boss and see if he wants to move this.