/*************************************************
 實驗任務 


**************************1．      C語言源程序（中斷法） ********************************/

#include "REG51.H"
sbit P14=P1^4;
sbit P11=P1^1;
sbit K1=P3^0;
sbit K2=P3^1;
sbit K3=P3^2;
sbit K4=P3^3;
unsigned char count;
unsigned char i,j,n;  

void main(void) 

{ 

  TMOD=0x01; 

  TH0=(65536-20000)/256; 

  TL0=(65536-20000)%256; 

  TR0=1; 

  ET0=1; 

  EA=1; 
  count=0;
  P1=0; 



  while(1)
  { 
 ;
  } ;
 

} 

  
 

void t0(void) interrupt 1 using 0 

{       
if(K1==0)

    switch(count)
        {
        case 0:
            P11=1;
            TH0=(65536-2500)/256;
            TL0=(65536-2500)%256;
            count=1;


            break;

  
  
        case 1:
            P11=0;
            TH0=(65536-17500)/256;
            TL0=(65536-17500)%256;
            count=0;

            break;
        }
  //if(count);
        
 else if(K2==0) 
    switch(count)
        {
        case 0:
            P11=1;
            TH0=(65536-1500)/256;
            TL0=(65536-1500)%256;
            count=1;
            break; 
  
        case 1:
            P11=0;
            TH0=(65536-18500)/256;
            TL0=(65536-18500)%256;
            count=0;

            break;
        }
 else if(K3==0) 
    switch(count)
        {
        case 0:
            P11=1;
            TH0=(65536-500)/256;
            TL0=(65536-500)%256;
            count=1;
            break; 
  
        case 1:
            P11=0;
            TH0=(65536-19500)/256;
            TL0=(65536-19500)%256;
            count=0;

            break;
        }
 else
        P14=~P14; 

}