//蜂鳴器之2002年的第一場雪
//P1.0接蜂鳴器

#include <reg52.h>

sbit SPK=P1^0;  //定義蜂鳴器為P1.0

void delayms(unsigned char ms);  //聲明延時子程序

unsigned int data j;  //定義直接尋址區變量j

//音符頻率表
unsigned char code song[636]={0xFF,0xFF,4,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xfd,0x08,2,				//21
							  0xFD,0x5B,4,0xFD,0x08,2,0xFC,0xAB,2,0xFC,0x0B,2,0xFC,0x0B,2,0xff,0xff,2,0xFc,0x0B,2,				//21
							  0xFC,0xAB,2,0xFC,0xAB,2,0xFC,0xAB,2,0xFC,0xAB,2,0xFC,0xAB,4,0xFC,0xAB,2,0xFC,0xAB,2,				//21	
							  0xFB,0x8F,2,0xFC,0x0B,2,0xFC,0x0B,4,0xff,0xff,8,									 				//12
							  0xff,0xff,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,4,0xFD,0x08,2,0xFD,0x08,2,				//21
							  0xFD,0x5B,4,0xFD,0x08,2,0xFC,0xAB,4,0xFD,0x08,6,                                  				//12
							  0xff,0xff,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFA,0x14,2,  //24
							  0xFC,0xAB,4,0xFC,0xAB,2,0xFC,0xAB,2,0xFC,0xAB,2,0xFC,0x0B,2,0xFC,0x0B,4,							//18
							  0xFF,0xFF,4,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,				//21	
							  0xFD,0x5B,4,0xFD,0x08,2,0xFC,0xAB,4,0xFD,0x08,6,											    	//12,183
						      0xFF,0xFF,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFA,0x14,2,  //24
							  0xFC,0xAB,4,0xFC,0xAB,2,0xFC,0xAB,2,0xFC,0xAB,2,0xFC,0x0B,2,0xFC,0x0B,4,						    //18
						      0xFF,0xFF,4,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xfd,0x08,2,				//21
                              0xFD,0x5B,4,0xFD,0x08,2,0xFD,0x5B,2,0xFC,0xAB,2,0xFC,0x0B,2,0xFC,0x0B,4,							//18
							  0xFF,0xFF,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFB,0x8F,4,0xFB,0x8F,2,0xFB,0x03,2,				//21
							  0xFC,0x0B,4,0xFB,0x8F,2,0xFC,0x0B,2,0xFB,0x03,2,0xfa,0x14,2,0xfa,0x14,4,                          //18
						      0xFF,0xFF,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,0xFD,0x08,2,  //24
							  0xFD,0x5B,4,0xFD,0x08,2,0xFD,0x5B,2,0xFC,0xAB,2,0xFC,0x0B,2,0xFC,0x0B,4,							//18
							  0xff,0xff,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFA,0x14,2,  //24
							  0xfc,0xab,4,0xfc,0xab,2,0xfc,0xab,2,0xfb,0x8f,2,0xfc,0x0b,2,0xFC,0x0B,4,						    //18,204
							  0xFF,0xFF,2,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,2,0xFd,0x08,4,0xFd,0x08,2,	            //21
							  0xfd,0x5b,4,0xfd,0x08,2,0xfc,0xab,4,0xfc,0x0b,6,													//12
							  0xFF,0xFF,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,	//24	
						      0xFC,0x0B,4,0xFB,0x8F,2,0xFC,0x0B,2,0xFB,0x03,2,0xfa,0x14,2,0xfa,0x14,4,							//18	
						      0xff,0xff,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFA,0x14,2,  //24
							  0xfb,0x03,2,0xfb,0x03,2,0xfb,0x03,2,0xfa,0x14,2,0xfa,0x14,1,0xf9,0x5b,1,0xf8,0x2a,2,0xf8,0x2a,4,  //24
							  0xff,0xff,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFA,0x14,2,  //24
							  0xfb,0x8f,2,0xfc,0x08,2,0xfc,0x08,2,0xfc,0x08,10,													//12
							  0xff,0xff,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFA,0x14,2,  //24
							  0xfb,0x03,2,0xfb,0x03,2,0xfb,0x03,2,0xfa,0x14,2,0xfa,0x14,1,0xf9,0x5b,1,0xf8,0x2a,2,0xf8,0x2a,4,  //24,207				
							  0xff,0xff,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x8F,2,0xFB,0x03,2,0xFA,0x14,2,  //24
							  0xfc,0xab,2,0xfd,0x08,2,0xfd,0x08,2,0xfd,0x08,2,0xff,0xff,4,0xff,0xff,4};							//18,42,636	

void main()
{
	TMOD=0x01;  //定時計數器T0工作在定時器方式1,16位計數器
	IE=0x82;  //CPU開總中斷，T0開溢出中斷
	while(1)
	{
		j=0;  //初始化j=0
		while(j<636)
		{
			TR0=1;  //啟動T0
			if((song[j]==0xff)&&(song[j+1]==0xff))
			TR0=0;  //休止符用0xff,0xff表示,出現休止符時，T0禁止，不發聲。
			delayms(song[j+2]);  //每一音符唱多長.
			j=j+3;
		}
	}
}

//T0中斷服務子程序
void timer0() interrupt 1 using 1  //每一音符唱多高
{
	TH0=song[j];
	TL0=song[j+1];
	SPK=!SPK;	
}

//基本延時子程序(16分之1拍的時間)
void delayms(unsigned char ms)
{
	unsigned int i;	
	while(ms--)
	{
		for(i=0;i<12000;i++);
	}
	TR0=0;
}