/*****************************************************************************
P1口的應用（二）
******************************************************************************/
#include"reg51.h"
#define uint unsigned int
#define uchar unsigned char
sbit DIPswitch=P1^0;
sbit redLED=P1^1;
sbit sounder=P1^7;
void delay(void)    //延時
{ unsigned char i;    
     {   for(i=0;i<125;i++)
       {;}
     }
}
void main(void)
{
P1=0XFF;
while(1)
  if (DIPswitch==0) 
     {redLED=~redLED; sounder=0; delay(); 
      sounder=1; delay(); }
   else
     {;}
}