2.c

刚学时编的小程序

	 #include   <reg51.h>   
    
  #define   uchar   unsigned   char   
  #define   uint   unsigned   int   
    
  code   uchar   ledcode[]={0x3f,   0x06,   0x5b,   0x4f,   0x66,   0x6d,   0x7d,   
0x07,0x7f,   0x6f,   0x77,   0x7c,   0x39,   0x5e,   0x79,   0x71};                 
    
  sbit   K0=P2^0;   
  sbit   K1=P2^1;   
  sbit   K2=P2^2;   
  sbit   K3=P2^3;   
    
  uchar   rdata;   
  uchar   ledbuf[4];         //数码管显示缓冲   
    
  uchar   receive   (void);               //单片机接收函数   
  void   display   (void);                 //单片机显示函数   
  void   delay   (uint   tc);   
    
  void   main   (void)   
  {   
    TMOD=0x20;   
    TL1=0xfa;   
    TH1=0xfa;   
    TR1=1;   
    SCON=0x50;   
    PCON=0x00;   
    while(1)   
    {   
      do   
      {   
    if   (   receive()   )   display();   
  }while(   receive()   );   
      display();   
    }   
  }   
    
  uchar   receive   (void)   
  {   
    while(RI==0)   return(0);   
    RI=0;   
    rdata=SBUF;   
    SBUF=rdata;   
    while(TI==0);   
    TI=0;   
  }   
    
  void   display   (void)   
  {   
    ledbuf[0]=ledbuf[1];   
    ledbuf[1]=ledbuf[2];   
    ledbuf[2]=ledbuf[3];   
    ledbuf[3]=ledcode[rdata];                 //移位   
    delay(500);   
    P0=ledbuf[0];K0=0;delay(200);K0=1;   
    P0=ledbuf[1];K1=0;delay(200);K1=1;   
    P0=ledbuf[2];K2=0;delay(200);K2=1;   
    P0=ledbuf[3];K3=0;delay(200);K3=1;   
    delay(500);   
  }   
    
  void   delay   (uint   tc)   
  {   
    uchar   i;   
    for   (i=0;i<tc;i++)   
  {}   
  }