1+.asm

51单片机的“数码管加减一”的演示程序

          org   0000h
;…………主程序……………………………….
  main: mov   dptr,#distab
        mov   p2,#11000000b
     

   ;…………循环显示子程序………………………………
start:  
        jnb     p1.5,start1
        acall  delay                     
        jb     p1.0,start
        ajmp   start2
        
start2:
        inc    r7
        jnb    p1.0,$
        acall xianshi
        
        cjne  r7,#10,start
        mov   r7,#0
        acall xianshi         
        ajmp  start
start1: cjne   r7,#0,start4
        mov  r7,#10
        acall xianshi
        ajmp  start 
start4:
        dec    r7
        acall  xianshi
        jnb     p1.5,$
        ajmp    start
        
xianshi:mov    a,r7
        movc   a,@a+dptr
        mov    p2,a        
        ret
            
;……… …读键子程序……………………………

delay: mov     r6,#0
delay1: mov    r5,#0
        djnz   r5,$
        djnz   r6,delay1
        ret
                
;…………数据表……………………………….
distab:  DB  0C0h,0F9h,0A4h,0B0h,99h,92h,82h,0F8h,80h,90h