测频gate.c

51定时器常用例子包括测频率测脉宽产生波形

#include"at89x52.h"
#define uchar unsigned char
#define uint  unsigned int
uchar code  tv[]={0xfe,0xfd,0xfb,0xf7};
uchar code  a[]={0x3f,0x06,0x5b,0x4f,
             0x66,0x6d,0x7d,0x07,0x7f,
             0x6f,0x77,0x7c};
uchar data  led[4];
uint data f;


void delay(void)
{
uint i;
for(i=0;i<100;i++);
}


ledxianshi()
{
  uchar k,i;
  led[0]=f/1000;
  led[1]=f%1000/100;
  led[2]=f%100/10;
  led[3]=f%10;
  		
	for(k=0;k<4;k++)
	 { i=led[k];
	   P0=a[i];
	   P2=tv[k];
           delay();
	 }
 } 

void main()
 {
  TMOD=0x50;
  TH1=0; 
  TL1=0;
     while(1)
     {while(P3_3==1);
      while(P3_3==0);
      TR1=1;
      while(P3_3==1);
      while(P3_3==0);
      TR1=0;
      f=(TH1<<8)+TL1;
      f=f;
      while(1)
      {ledxianshi();}
     }
 }