ljw1.lst

通过单片机的I/O引脚以软件延时方式产生方波

C51 COMPILER V7.07   LJW1                                                                  11/06/2007 23:48:37 PAGE 1   


C51 COMPILER V7.07, COMPILATION OF MODULE LJW1
OBJECT MODULE PLACED IN ljw1.OBJ
COMPILER INVOKED BY: d:\Keil\C51\BIN\C51.EXE ljw1.c

stmt level    source

   1          //功能说明:
   2          //通过单片机的I/O引脚以软件延时方式产生方波，使蜂鸣器发出"嘀、嘀…"声音。
   3          
   4          #include<AT89X51.h>            
   5          void delay250( unsigned int k );
   6          main( )                        
   7          {   
   8   1         for (;;)                     
   9   1         {
  10   2          while(P2_7==0)               
  11   2           {              
  12   3           unsigned int j; 
  13   3                  for(j=0;j<400;j++)        
  14   3             {
  15   4               P3_4=0;                 
  16   4                     delay250(2);             
  17   4               P3_4=1;                 
  18   4                     delay250(2);             
  19   4             }  
  20   3           delay250(800);             
  21   3          }       
  22   2         }                                           
  23   1      }
  24          void delay250(unsigned int k)    
  25          {  
  26   1        unsigned int j,i;
  27   1      for(i=0;i<k;i++)
  28   1          {
  29   2           for(j=0;j<25;j++); 
  30   2          }
  31   1      }        


MODULE INFORMATION:   STATIC OVERLAYABLE
   CODE SIZE        =     84    ----
   CONSTANT SIZE    =   ----    ----
   XDATA SIZE       =   ----    ----
   PDATA SIZE       =   ----    ----
   DATA SIZE        =   ----       2
   IDATA SIZE       =   ----    ----
   BIT SIZE         =   ----    ----
END OF MODULE INFORMATION.


C51 COMPILATION COMPLETE.  0 WARNING(S),  0 ERROR(S)