51单片机 方波

51单片机 方波

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产生一个占空比为80%的方波。

#include <reg51.h>

unsigned char a,b;
sbit  OUT = P0^0;

// 定时器中断初始化
void timer0_init()
{
    EA = 0;
    TMOD = 0X01;
    ET0 = 1;
    TR0 =1;
    TH0 = (65535-10000)/256;
    TL0 = (65535-10000)%256;
    EA = 1;
}

// 定时器中断
void timer0() interrupt 1
{
    TH0 = (65535-10000)%256;
    TL0 = (65535-10000)%256;
    a++;
}

void main()
{
    void timer0_init();
    while(1)
    {
        if(a==4)
        {
            OUT = 0;
        }
        else
        {
            OUT = 1;
        }
        if(a==5)
        {
            a = 0;
        }
    }
}