//參考程序 B.WYINYUE.C    此程序將某段音樂用特定的頻率播放出來
#include <C8051F020.h>
#include <ctype.h>
#pragma ot(0)
#define uint  unsigned int
#define uchar unsigned char
#define OSFREQ 6000000l                 /*所使用的晶振頻率*/
/**************音符頻率表****************/
uint code notefreq[]={ 	523, 587, 659, 698, 784, 880, 988,
						1047,1175,1319,1396,1568,1760,1976,
						2093,2349,2637,2793,3136,3520,3961};
/*************音名***************/
uchar code notename[]={	'c','d','e','f','g','a','b',
						'1','2','3','4','5','6','7',
						'C','D','E','F','G','A','B',0};
/*************半音頻率表*****************/
uint code halfnotefreq[]={ 	554, 622, 740, 831, 933,
							1109,1245,1480,1161,1865,
							2218,2489,2960,3322,3729};
/*************音名***************/
uchar code halfnotename[]={	'c','d','f','g','a',
							'1','2','4','5','6',
							'C','D','F','G','A',0};
//sbit  BEEP_PWR=P1^0;
uchar  FreqSandH,FreqSandL;  /*產生方波的定時器的初值*/
uchar timer1cnt;             /*定時器延時計數        */
uchar timer1cntflg;          /*定時器定時完成標志    */
void timer0int () interrupt 1//定時器0中斷用來產生方波

{
	TH0=FreqSandH;		
	TL0=FreqSandL;
	P5 = P5 ^ 0x10;		// change state of P5.4按位異或
}
void delay(uchar time)// 	延時
{
	uchar i;
	uint j;
	for(i=0;i<time;i++)
    	for(j=0;j<0x900;j++);
}
void Sound(uint freq)// 發聲
{
	uint timreg;
	timreg=65536l-(OSFREQ/(24l*freq));
	FreqSandH=timreg/256;
	FreqSandL=timreg&0x00ff;
	TR0=1;
	ET0=1;
}
void SoundOff(void)// 停止發聲
{
	TR0=0;		  
	ET0=0;
	P5 = P5 & 0xef;
}
uint GetFreq(uchar ch,uchar flg)// 依據音名取對應的頻率
{
	uchar * pn,i=0;
	uint * pf;
	if(flg)   {pn=halfnotename; pf=halfnotefreq;}
	else      {pn=notename;     pf=notefreq;}
	while(1)
    {
		if(pn[i]==0)     return 0;
     	if(ch==pn[i])  return pf[i];
     	i++;
    }
}
void Play(char * str)
{
	uchar i=0,ch,halfflg=0;
	uchar lasttime;
	uint freq;
	/*無效看門狗*/
   	WDTCN = 0xde;
   	WDTCN = 0xad;
	OSCICN=0x14;		/*使用內部晶振(2MHZ)*/
	while(1)
    {
		for(;;i++)
        {
			ch=str[i];   /*允許曲譜用空格符 '|'符，換行回車等分隔以便閱讀*/
          	if((ch==' ')||(ch=='|')||(ch=='\r')||(ch=='\n')) {i++;continue;}
          	if(!ch) {SoundOff(); return;}         /*樂曲結束則播放完畢*/
          	if(ch=='#')  {halfflg=1;  continue;}  /*半音標志*/
          	if(isdigit(ch)||isalpha(ch))
            {
				freq=GetFreq(ch,halfflg);		/*從音名獲取頻率*/
               	lasttime=16;
               	break;
            }
          	else {halfflg=0;  continue;}
        }
      	i++;
      	ch=str[i];       /*從下一個符號獲取額外音長符號*/
      	while(1)
        {
			if(!ch) break;
          	if(isdigit(ch)||isalpha(ch)) break;   /*非音長符號則下次處理*/
          	if(ch=='-') lasttime+=8;              /*額外延時一拍*/
          	if(ch=='.') lasttime+=4;              /*額外延時半拍*/
   if(ch=='_') lasttime/=2; /*下劃線相當于簡譜中音名下面的下劃線，延時減半*/
if(ch=='=') lasttime/=4; /*雙下劃線相當于簡譜中音名下面的雙下劃線，延時減為1/4*/
          	i++;
          	ch=str[i];
        }
     	if(freq!=0) Sound(freq);             	/*發聲*/
     	else        SoundOff();
     	delay(lasttime);                      	/*延時*/
     	SoundOff();
     	delay(1);                    			/*兩個引之間的間歇*/
    }
}
void main(void)
{
	//uint i;
TMOD=0x01; //設定T0為方式1(16位計數)
ET0=1;    //允許TO中斷
EA=1;     //開中斷
delay(10); //延時
Play("1_1_5_5_6_6_5   4_4_3_3_2_2_1  5_5_4_4_3_3_2 5_5_4_4_3_3_21_1_5_5_6_6_5  4_4_3_3_2_2_1"); /*滿天都是小星星*/
Play("1_2_3_1_  1_2_3_1_  3_4_5 3_4_5  5=6=5=4=3_1_ 5=6=5=4=3_1_ 2_g_12_g_1");    /*兩只老虎*/
Play("a-a1-a2--a-b1b13-2a--a-- a-33-12--a-b1b13-21--1-- 5-55432--a-b1-12123--3-- 1-1_1_1235--4-32-b3-2a--a--a-66565--4-34-56543--3--1-1_1_1235--4-32-b3-2a--a--"); /*山楂樹*/
Play("5._3=2_1_5-12_3_g-5.3_23_5_1a_3_2-356.5_352._3=2_1_a32_21_a1g05.3_6562_3_50"); /*學習雷鋒好榜樣*/
Play("C-53.2_1530C-53.2_1650 5_C6_5_C05_C6_5_6_0_3_C.6_53C.6_C0C53_6_5_3_2.1_30_5_C56_C_6_5_33_1_6-60C._C=5_5_2._3=5_5_6.5_6DC6_5_C6_5_33_5_C-");  /*團結就是力量*/
Play("3- 2_3_4_3 3- 2_3_4_3 3- 4- 3_4_5_4 4- 3-2-  3- 2_3_4_3 3- 2_3_4_3 3-4- 3_4_5_4 4- 3-2");/*許巍－星空前奏*/
Play("543 3_2_1_2_30 g53 3_2_1_2_30 a65 4_3_2_3_4 1 b a g");/*許巍-時光*/
Play("g_g_ag  1b- g_g_ag  21-  g_g_53  1ba 004_4_  312  1--1  ");/*生日快樂*/
	SoundOff();
    while(1);
	}