程序功能：让RC口的八个灯亮65MS灭65MS采用定时器0中断来完成

程序如下：

  tmr0         equ             01h
  pcl             equ             02h
status       equ             03h
option_reg equ           81h
     intcon         equ           0bh
     portc           equ           07h
       trisc           equ           87h
tmr0_b         equ           0
       w                   equ           0
         f                   equ           1
    rp0               equ           5
     t0if             equ           2
w_temp         equ           7fh
portc_b       equ           23h
flag             equ           24h                
                   org             0000h
                   nop
                   goto           main
                   org             0004h
  tmr0_serv
                   MOVwf         w_temp
                   bcf             intcon,t0if
                   MOVlw         tmr0_b
                   MOVwf         tmr0
                   btfss         flag,0
                   goto           loop0
                   bcf             flag,0
                   goto           loop1
loop0
                   bsf             flag,0
                   MOVlw         0ffh
                   MOVwf         portc
                   goto           retfie_b
loop1        
                   MOVlw         00h
                   MOVwf         portc
retfie_b
                   MOVf           w_temp,w
                   retfie
           main  
                   bsf           status,rp0
                   MOVlw       0
                   MOVwf       trisc
                   MOVlw       07h
                   MOVwf       option_reg
                   bcf           status,rp0
                   MOVlw       00h
                   MOVwf       portc
                   MOVlw       0a0h
                   MOVwf       intcon
                   bcf           intcon,t0if
                   MOVlw       tmr0_b
                   MOVwf       tmr0
                   goto         $
                   end
  以上程序已经运行通过