mzmfr.c

从各种VC源码中精选出来

#include<reg51.h>
#define uint unsigned int
#define uchar unsigned char
  
  
uchar bdata FLAG;
sbit FLAG1=FLAG^1;
sbit FLAG2=FLAG^2;
sbit P1_1=P1^1;
uchar data time,Dtime,Btime;
uint fetch_rate(void);


main()
{
   char  bdata JFLAG;
   char data state,Astate,Bstate,rate;
   do{
   	P1=0XFF;
   	FLAG=P1;
   	TXD=0;
   	JFLAG=FLAG>>6;
   	JFLAG=FLAG&0X03;
   	switch(JFLAG)
		{
   	case 0:
   		time=2;Dtime=20;break;
   	case 1:
   		time=4;Dtime=40;break;
		case 2:
   		time=6;Dtime=60;break;
		case 3:
   		time=8;Dtime=80;break;
   	}
   Btime=Dtime;
   JFLAG=FLAG>>3;JFLAG=JFLAG&0X07;
   switch(JFLAG)
		{
   	case 0:
   		state=50;break;
   	case 1:
   		state=100;break;
   	case 2:
   		state=150;break;
   	case 3:
   		state=200;break;	
		case 4:
   		state=250;break;
   	case 5:
   		state=300;break;	
   	case 6:
   		state=350;break;	
   	case 7:
   		state=400;break;
	}
   FLAG1=0;
   TMOD=0x51;
   TH1=0;
   TL1=0;
   TH0=0x3C;
   TL0=0XB0;
   TR0=1;
   TR1=1;
   ET0=1;
   EA=1;
   rate=fetch_rate();
   if(!FLAG2)
	{
      	Astate=state+2*state/10;
      	if(rate<=state)
			{
      		TXD=1;
      		do
				{
      		rate=fetch_rate();
      		}while(rate<=Astate);
      	TXD=0;
      	}	
    }
     else
	  {
     Bstate=state-2*state/10;
     if(rate>=state)
	  {
     	TXD=1;
     	do
		{
     	rate=fetch_rate();
		}while(rate>=Astate);
		TXD=0;
		}	
     }
 }while(1);
}
unsigned int fetch_rate()
{
      uint count;
      do{}while(!FLAG1);
      FLAG1=0;
      count=TH1*256+TL1;
      TH1=0;
      TL1=0;
      Dtime=Btime;
      return(count/time);
   }
   timer0() interrupt  1 using 1
   {
   	TH0=0x3c;
   	TL0=0XB0;
   	Dtime=Dtime-1;
   	if(Dtime==0){FLAG=1;}
   }