; 輸出 50% (5:5) 占空比 PWM
; 輸出 10% (1:9) 占空比 PWM
; 輸出 90% (9:1) 占空比 PWM
       ORG   0000H
       ljmp  LOOP
       ORG   0030H
OUTPUT equ   P1.0

Loop:
       clr   OUTPUT
       mov   a, #5
       Acall  Delay
       setb  OUTPUT
       MOV   A, #5
       Acall  Delay
       Sjmp  Loop

Delay:
       mov   r0, #80
DLoop:
       djnz  r0,DLoop
       djnz  acc, DLoop
       ret

       end