求助

我想通过那个按钮控制红绿灯全变红，但是点完按钮没有任何反应。。。。新手求指教
ORG 0000H
LJMP MAIN
ORG 0003H
LJMP INT
ORG 0030H
MAIN: SETB PX0
SETB EA
SETB EX0
CLR IT0
SETB IE0
LOOP: MOV P1,#0CH
MOV P0,#50
MOV R1,#200
AP1: LCALL DELAY
DJNZ R1,AP1
MOV P1,#0AH
MOV P0,#50
MOV R1,#40
AP2: LCALL DELAY
DJNZ R1,AP2
MOV P1,#21H
MOV P0,#30
MOV R1,#120
AP3: LCALL DELAY
DJNZ R1,AP3
MOV P1,#11H
MOV P0,#10
MOV R1,#40
AP4: LCALL DELAY
DJNZ R1,AP4
SJMP LOOP
ORG 0300H
INT: PUSH P1
MOV P1,#09H
MOV R1,#60
AP5: LCALL DELAY
DJNZ R1,AP5
POP P1
RETI
ORG 0300H
DELAY: MOV R4,#10
LP1: MOV R5,#50
LP2: MOV R6,#248
NOP
LP3: DJNZ R6,LP3
DJNZ R5,LP2
DJNZ R4,LP1
RET
END