倒计时.c

单片机C语言15个实验附有原理图和程序 是我的课程作业 以经过实践验证

//anti_clock_disp.c
#include<reg51.h>
#include<stdio.h>
#include<intrins.h>
#define hi1 0xf0
#define lo1 0x00
#define hi 0x3c//初值
#define lo 0xb0
sbit P30=P3^0;sbit P37=P3^7;sbit clk=P0^7;sbit sda=P0^6; //74LS164
unsigned char disp[4],mask=0xee;
unsigned char code ledk[10]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
unsigned char min=2,sec=0,t0_count;

void delay(unsigned int n)
 {unsigned int i,j;
  for(i=0;i<n;i++)
     for(j=0;j<n;j++)
       ;}
void shift(unsigned char dx)
{static unsigned char d;
   unsigned char j=0;
    d=dx;
   	while(j<8)
	{if((d&0x80)!=0) sda=1;
       else  sda=0;
	   clk=0;clk=1;
	   d<<=1;j++;}  }
void t0() interrupt 1 
{ TH0=hi;TL0=lo;t0_count++;
  if(t0_count==20)
    {if (sec!=0)sec--;
       else if (min !=0 ){min --; sec =60; sec--;}
          t0_count=0;}} 
void t1() interrupt 3
  {P30=!P30;TH1=hi1;TL1=lo1;}
void hextodec(j,xx) 
 unsigned char j,xx;
 { disp[j]=xx/10;   j--;    disp[j]=xx%10;}
void out()
 {static unsigned char i;
  P2=mask;
  if(i==2 && t0_count<=10)shift(ledk[disp[i]]|0x80);
        else shift(ledk[disp[i]]);
  mask=_crol_(mask,1);i++;if(i>3)i=0;}
void main(void)                                                                                                                                                                                         
{unsigned char i;
   TMOD=0x01;TH0=hi;TL0=lo;TH1=hi1;TL1=lo1;
   EA=1;ET0=1;ET1=1;TR0=1;P30=1;
   while(1)
   {out();delay(20);
	hextodec(3,min);hextodec(1,sec);
    if(min==0 && sec<=3 && t0_count<6)TR1=1;
             else {TR1=0;P30=1;}		   
	if(min==0 && sec==0)
             {TR0=0;TR1=0;for(i=0;i<4;i++)disp[i]=0;EA=0;} }
}