基于单片机的频率计的设计(C51语言)

// 用定时器1定时,使用方式一,晶振频率为11.0592MHZ,常数为4C00;

//用外部中断一计数,每中断一次,count加一

//使用P1口接的八个发光二极管显示

//本程序为一个网友应邀而写,在硬件上测试通过,在低频率时,效果不错.

#include<reg51.h>
                         unsigned                      int t1oc=20;//5000;
                         unsigned                      int                      count=0,precount;
                         void display(unsigned int dis)
                               {
                                 P1=dis;//显示语句
                                }
                         void t1int() interrupt 3
                                     {
                                        TR1=0;                  
                                        t1oc--;
                                            TH1=0x4c;//72;//56;
                                            TL1=0x00;//72;//56;
                                        if(t1oc==0)
                                           {
                                               t1oc=20;//5000;
                                               precount=count;
                                               count=0;
                                            }
                                           TR1=1;
                                     }
                               void int0int() interrupt 0  
                                              {               

                                                EX0=1;
                                                 count++;
                                                EX0=0;
                                              }
                                void main(void)
                                         {
                                          TMOD=0x10;//0x20;
                                          TH1=0x4c;//72;//56;
                                            TL1=0x00;//72;//56;
                                          EA=1;
                                          EX0=1;IT0=1;
                                          ET1=1;
                                          TR1=1;
                                          while(1)
                                            {
                                             display(precount);
                                            }   
                                         }