org 0000h
             jmp start
             org 0bh
             jmp tim0
            
             
start1:       mov tmod,#00010001b    ;兩只老虎
             mov ie,#10000010b
             setb tr0
             ;setb p2.7    ;兩只老虎
start:       cpl p2.7    ;兩只老
             acall delay
             
             ;acall delay
             ;acall delay
             acall delay
             jmp start
             
             
delay:      mov r7,#02h
d2:         mov r4,#125
d3:         mov r3,#248
            djnz r3,$
            djnz r4,d3
            djnz r7,d2
            djnz r5,delay
            ret
            
tim0:     push acc
          push psw
          mov tl0,20h
          mov th0,21h
          cpl p2.7;p3.5
          pop psw
          pop acc
           reti            


end