51单片机输出两路PWM波（互补带死区）频率可调

#include <REGX52.H>
sbit LED1=P2^0;    //第一路PWM
sbit LED2=P2^1;    //第二路PWM
sbit KeyNum=P3^1;      //按键
unsigned int f=1  ;   //默认1HZ
unsigned int result;    //result = 65535-100000/f
unsigned int Counter1,Counter2;
unsigned char Compare=4,Num=1;     //默认占空比40%，死区10%，可以改值改变占空比

void Delay(unsigned int xms)     //延时函数
{
	unsigned char i, j;
	while(xms--)
	{
		i = 2;
		j = 239;
		do
		{
			while (--j);
		} while (--i);
	}
}


void Timer0_Init()         //定时器初始化

{
	TMOD &= 0xF0;		//设置定时器模式
	TMOD |= 0x01;		//设置定时器模
    TH0 = (65535-100000)/256;		//将高八位储存在寄存器
	TL0 = (65535-100000)%256;		//将低八位储存在寄存器
	TF0 = 0;		//清除TF0标志
	TR0 = 1;		//定时器0开始计时
	ET0=1;
	EA=1;
	PT0=0;
}

void key_scan()        //按键加频率（1~20HZ按键加1,20~50HZ按键加5,50~100HZ按键加10）	
{		
	if(KeyNum == 0)
		{
		Delay(20);while(P3_1==0);Delay(20);
		if         (f<20)    {f ++ ;}
		else if    (f<50)    {f += 5;}
		else if    (f<100)   {f += 10;}
        else       {f=1;}
		}
}

		
void Timer0_Routine() interrupt 1        //定时器中断
{	
    TH0 = (result/256);		//将高八位储存在寄存器
	TL0 = result%256;		//将低八位储存在寄存器
	Counter1++;
    Counter2=Counter1;
	Counter1%=10;
	if(Counter1<Compare)
	{
		LED1=1;
	}
	else                             
	{
		LED1=0;
	}                                //第一路PWM
	Counter2%=10;                    //第二路PWM
	if(Counter2<(Compare+Num))
	{
		LED2=0;
	}
	if((Counter2>(Compare+Num))&&(Counter2<(Compare+Compare+Num)))
	{
		LED2=1;
	}
	
	else
	{
		LED2=0;
	}
	
}

void main(void)
{
	Timer0_Init();
	while(1)	
	{
		result = 65535-100000/f;
		key_scan();
	}
}