099.c

本文件包含了使用C语言编写单片机的各种入门程序

//================================================                                                  
#include <reg51.h>                            
sbit dat=P0^2;                                   
sbit clk=P0^3;                                     
//================================================ 
code char led[11]={0x11,0xd7,0x32,0x92,0xd4,0x98,
0x18,0xd3,0x10,0x90,0xff};
//================================================
 unsigned char second,third;
//===========主程序===============================
void main()
{
  void display();                  //函数原形声明
  void send_byte(unsigned char t);
  void delay();
 
  second=99;third=99;
  while(1)
  {
    if(second>=99)
    {second=0;
	if(third>=99) third=0;
	else third=third+1;
	}
    else  second=second+1;
    delay();                    //调用延时
    display();                  //调用显示子程序
   }     
}  
//===========拆分显示程序=============================
void  display()    
{
 send_byte(second%10);          //拆分个位，秒个位
 send_byte(second/10);          //拆分十位，秒十位
 send_byte(third%10);          //拆分个位，秒个位
 send_byte(third/10);          //拆分十位，秒十位
 send_byte(10);
 send_byte(10);
 send_byte(10);
 send_byte(10);
}  
//============移位子程序==============================
void send_byte(unsigned char t)
{
 unsigned  char i,one_byte;
 one_byte=led[t];//以t为偏移量，读取code  char 中的数据
 for(i=0;i<8;i++)
 {
  clk=0;                    //时钟线清零
  if(one_byte&0x80)dat=1;   //与、判断，往数据线送最高位
  else dat=0;
  //dat=(one_byte&0x80);   //往dat送数,先送最高位
  clk=1;                   //上跳
  clk=0;                   //下跳
  dat=0;                   //dat清零，确保数据的准确性
  one_byte=one_byte<<1;    //左移一位
  }
}

//=============延时子程序=============================
void delay()
{unsigned int i,j; 
 for(i=0;i<25000;i++);  //外循环
 for(j=0;j<10;j++);    //内循环
}
//====================================================
//end