led tắt dần port 1 (8951)

ORG 00H
MAIN:
MOV P1,#11111111B;Trạng thái led sáng hết
CALL DELAY
MOV P1,#11111110B;Led p1.0 tắt
CALL DELAY
MOV P1,#11111100B;led p1.0 tắt,p1.1 tắt
CALL DELAY
MOV P1,#11111000B
CALL DELAY
MOV P1,#11110000B
CALL DELAY
MOV P1,#11100000B
CALL DELAY
MOV P1,#11000000B
CALL DELAY
MOV P1,#10000000B
CALL DELAY
MOV P1,#00000000B
CALL DELAY
JMP MAIN
DELAY:
MOV R0,#200
LAP:
MOV R1,#200
LAP2:
NOP
NOP
NOP
DJNZ R1,LAP2
DJNZ R0,LAP
RET
END