ORG 0000H
AJMP MAIN
ORG 0060H
MAIN: MOV 20H,#00H
LP: MOV A,20H
MOV P1,A
ADD A,#1
MOV 20H,A
LCALL DELAY
SJMP LP
DELAY: MOV R7, #100
WAIT: MOV R6,#200
DJNZ R6,$
DJNZ R7,WAIT
RET
END