org    0000h
             ajmp   main
             org    0030h
main:        mov    tmod,#010h
             mov    th0,#100
             mov    tl0,#100
             mov    r5,#00h
             mov    r6,#00h
             mov    r7,#00h
             setb   tro
chenxu1:     mov    p0,#01111111b
             acall  yan1
             mov    p0,#10111111b
             acall  yan1
             mov    p0,#11011111b
             acall  yan1
             mov    p0,#11101111b
             avall  yan1
             mov    p0,#11110111b
             acall  yan
             mov    p0,#11111011b
             acall  yan1
             mov    p0,#11111101b
             acall  yan1
             mov    p0,#11111110b
             acall  yan1
             ajmp   chenxu1
yan1:        jnb    tf0,yan1
             inc    r5
             cjne   r5,#60,yan1
             mov    r5,#00h
             inc    r6
             cjne   r6,#100,yan1
             mov    r6,#00h
             inc    r7
             cjne   r7,#100,yan1
             mov    r7,#00h
             ajmp   yan1
             ret
             end