9999-0.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 sda=P0^2;
sbit scl=P0^3;
unsigned int num,b;
code int led[11]={0x11,0xd7,0x32,
0x92,0xd4,0x98,0x18,0xd3,0x10,
0x90,0xff};

void delay(int k)
{
int u;
for(;k>0;k--)
for(u=0;u<500;u++);
}

shift(int t)
{
int n,led1=led[t];
for(n=0;n<8;n++)
{
scl=0;
if(led1&0x80)sda=1;
else sda=0;
scl=1;
scl=0;
sda=0;
led1=led1<<1;
}
}

display()
{
b=0x0a;
shift(b);
shift(b);
shift(b);
shift(b);
b=num%10;
shift(b);
b=num%100/10;
shift(b);
b=num%1000/100;
shift(b);
b=num/1000;
shift(b);
}

void main()
{
delay(200);
for(num=9999;num>0;num--)
{
display();
delay(500);
}
}