fat.i

以AVRMEGA32播放SD卡中的WAV音乐

// CodeVisionAVR C Compiler
// (C) 1998-2004 Pavel Haiduc, HP InfoTech S.R.L.

// I/O registers definitions for the ATmega32


#pragma used+
sfrb TWBR=0;
sfrb TWSR=1;
sfrb TWAR=2;
sfrb TWDR=3;
sfrb ADCL=4;
sfrb ADCH=5;
sfrw ADCW=4;      // 16 bit access
sfrb ADCSRA=6;
sfrb ADCSR=6;     // for compatibility with older code
sfrb ADMUX=7;
sfrb ACSR=8;
sfrb UBRRL=9;
sfrb UCSRB=0xa;
sfrb UCSRA=0xb;
sfrb UDR=0xc;
sfrb SPCR=0xd;
sfrb SPSR=0xe;
sfrb SPDR=0xf;
sfrb PIND=0x10;
sfrb DDRD=0x11;
sfrb PORTD=0x12;
sfrb PINC=0x13;
sfrb DDRC=0x14;
sfrb PORTC=0x15;
sfrb PINB=0x16;
sfrb DDRB=0x17;
sfrb PORTB=0x18;
sfrb PINA=0x19;
sfrb DDRA=0x1a;
sfrb PORTA=0x1b;
sfrb EECR=0x1c;
sfrb EEDR=0x1d;
sfrb EEARL=0x1e;
sfrb EEARH=0x1f;
sfrw EEAR=0x1e;   // 16 bit access
sfrb UBRRH=0x20;
sfrb UCSRC=0X20;
sfrb WDTCR=0x21;
sfrb ASSR=0x22;
sfrb OCR2=0x23;
sfrb TCNT2=0x24;
sfrb TCCR2=0x25;
sfrb ICR1L=0x26;
sfrb ICR1H=0x27;
sfrb OCR1BL=0x28;
sfrb OCR1BH=0x29;
sfrw OCR1B=0x28;  // 16 bit access
sfrb OCR1AL=0x2a;
sfrb OCR1AH=0x2b;
sfrw OCR1A=0x2a;  // 16 bit access
sfrb TCNT1L=0x2c;
sfrb TCNT1H=0x2d;
sfrw TCNT1=0x2c;  // 16 bit access
sfrb TCCR1B=0x2e;
sfrb TCCR1A=0x2f;
sfrb SFIOR=0x30;
sfrb OSCCAL=0x31;
sfrb TCNT0=0x32;
sfrb TCCR0=0x33;
sfrb MCUCSR=0x34;
sfrb MCUCR=0x35;
sfrb TWCR=0x36;
sfrb SPMCR=0x37;
sfrb TIFR=0x38;
sfrb TIMSK=0x39;
sfrb GIFR=0x3a;
sfrb GICR=0x3b;
sfrb OCR0=0X3c;
sfrb SPL=0x3d;
sfrb SPH=0x3e;
sfrb SREG=0x3f;
#pragma used-

// Interrupt vectors definitions


// Needed by the power management functions (sleep.h)
#asm
	#ifndef __SLEEP_DEFINED__
	#define __SLEEP_DEFINED__
	.EQU __se_bit=0x80
	.EQU __sm_mask=0x70
	.EQU __sm_powerdown=0x20
	.EQU __sm_powersave=0x30
	.EQU __sm_standby=0x60
	.EQU __sm_ext_standby=0x70
	.EQU __sm_adc_noise_red=0x10
	.SET power_ctrl_reg=mcucr
	#endif
#endasm




/*------------------------------------------------------------------*/
/*                      Redefine Data Size                          */
/*------------------------------------------------------------------*/

void TransmitByte( unsigned char data );
//-----------------------------------------------------






/* CodeVisionAVR C Compiler
   Prototypes for standard library functions

   (C) 1998-2003 Pavel Haiduc, HP InfoTech S.R.L.
*/




#pragma used+

int atoi(char *str);
long int atol(char *str);
float atof(char *str);
void itoa(int n,char *str);
void ltoa(long int n,char *str);
void ftoa(float n,unsigned char decimals,char *str);
void ftoe(float n,unsigned char decimals,char *str);
void srand(int seed);
int rand(void);
void *malloc(unsigned int size);
void *calloc(unsigned int num, unsigned int size);
void *realloc(void *ptr, unsigned int size); 
void free(void *ptr);

#pragma used-
#pragma library stdlib.lib



//声明外部器件读写函数

extern unsigned char MMC_SD_ReadSingleBlock(unsigned  long sector, unsigned char* buffer);

extern unsigned char FAT_Init();//初始化
//extern unsigned long FAT_NextCluster(unsigned long cluster);//查找下一簇号





//extern unsigned int FAT_FindItem(unsigned long cluster, BYTE *name, struct FileInfoStruct *FileInfo);//查找文件
//extern unsigned long FAT_OpenDir(BYTE * dir);//打开目录
//extern unsigned char Search(BYTE *dir,struct direntry *MusicInfo,WORD *Count,BYTE *type);//查找音乐文件

//void CopyDirentruyItem(struct direntry *Desti,struct direntry *Source);







 

extern unsigned char MMC_SD_SendCommand(unsigned char cmd, unsigned long arg);
extern void MMC_SD_Init (void); 

extern unsigned char MMC_SD_Reset(void);

extern unsigned char MMC_SD_ReadSingleBlock(unsigned long sector, unsigned char* buffer);

extern void SPI_High(void);








//低速模式 
void SPI_Low(void)
{
	SPCR =0x52;//_BV(SPE)|_BV(MSTR)|_BV(SPR1)|_BV(SPR0);
	SPSR &= 0xfe;        //关双速
}

//高速模式
void SPI_High(void)
{
	SPCR =0x50;//  _BV(SPE)|_BV(MSTR);
	SPSR |=0x01;// _BV(SPI2X); //开双速
}

//端口初始化，模式初始化  
void SPI_Init(void)
{
	DDRB |=0xbf  ;  //端口设置，主要是SPI
	SPI_Low(); //先低速
}



//sd卡初始化		
void MMC_SD_Init(void)
{
	SPI_Init();
	PORTB.2=1;//cs=1
}


//写读一个字节			//read and write one byte
unsigned char SPI_WriteByte(unsigned char val)
{
	SPDR = val;
	while(SPSR.7==0);
	return SPDR;
}



//sd卡写命令		
unsigned char MMC_SD_SendCommand(unsigned char cmd, unsigned long arg)
{
	unsigned char r1;
	unsigned char retry=0;
	
	SPI_WriteByte(0xff);
	PORTB.2=0  ;  //CS=0
	
	SPI_WriteByte(cmd | 0x40);//分别写入命令	
	SPI_WriteByte(arg>>24);
	SPI_WriteByte(arg>>16);
	SPI_WriteByte(arg>>8);
	SPI_WriteByte(arg);
	SPI_WriteByte(0x95);
	
	while((r1 = SPI_WriteByte(0xff)) == 0xff)//等待响应，	
		if(retry++ > 200) break;//超时退出		

	PORTB.2=1;   //cs=1

	return r1;//返回状态值					
}

//sd卡复位		
unsigned char MMC_SD_Reset(void)
{
	unsigned char i;
	unsigned char retry;
	unsigned char r1=0;
	retry = 0;
	SPI_Low();
        PORTB.2=1;//
	for(i=0; i<16; i++)
      SPI_WriteByte(0xFF);
     
	do
	{
		for(i=0;i<20;i++) SPI_WriteByte(0xff);
		r1 = MMC_SD_SendCommand(0, 0);//发idle命令
		retry++; 
		//TransmitByte(retry);
		if(retry>200) return 1;//超时退出	
	} while(r1 != 0x01);	


	retry = 0;
	do
	{
		r1 = MMC_SD_SendCommand(1, 0);//发active命令	
		retry++;
		if(retry>100) return 1;//超时退出		
	} while(r1);
	SPI_High();
	r1 = MMC_SD_SendCommand(59, 0);//关crc		

	r1 = MMC_SD_SendCommand(16, 512);//设扇区大小512
	return 0;//正常返回	
}

//读一个扇区		
unsigned char MMC_SD_ReadSingleBlock(unsigned long sector, unsigned char* buffer)
{
	unsigned char r1;
	unsigned int i;
	unsigned int retry=0;
        PORTB.2=1;//
	for(i=0; i<16; i++)
      SPI_WriteByte(0xFF);
	r1 = MMC_SD_SendCommand(17, sector<<9);//读命令	/9
	
	if(r1 != 0x00)
		return r1;

	PORTB.2=0  ;  //cs=0
	//等数据的开始	
	while(SPI_WriteByte(0xff) != 0xfe)if(retry++ > 1000){PORTB.2=1;return 1;}

	for(i=0; i<512; i++)//读512个数据	
	{
		*buffer++ = SPI_WriteByte(0xff);
	}

	SPI_WriteByte(0xff);//伪crc
	SPI_WriteByte(0xff);
	
	PORTB.2=1; //cs=1

	return 0;
}
/* 
//读一个扇区		
uint8 MMC_SD_ReadSingleBlock1(uint32 sector, uint8* buffer)
{
	uint8 r1;
	uint16 i;
	uint16 retry=0;
         MMC_SD_SendCommand(16, 256);
	r1 = MMC_SD_SendCommand(17, sector<<8);//读命令	/9
	
	if(r1 != 0x00)
		return r1;

	SPI_CS_Assert();  //cs=0
	//等数据的开始	
	while(SPI_WriteByte(0xff) != 0xfe)if(retry++ > 1000){SPI_CS_Deassert();return 1;}

	for(i=0; i<256; i++)//读512个数据	
	{
		*buffer++ = SPI_WriteByte(0xff);
	}

	SPI_WriteByte(0xff);//伪crc
	SPI_WriteByte(0xff);
	
	SPI_CS_Deassert(); //cs=1

	return 0;
} 
*/
unsigned char     bf[512];
unsigned char      secpclus; //每籁包函扇区数
unsigned int     fr_fatsec;   //FAT表首扇区
unsigned int        rodir;       // 根目录首扇区
unsigned char      firstrodirclus; //根目录的首籁号
unsigned long     filefirstclus;   //文件首籁号 
unsigned long     filesize;        //
 unsigned char (* FAT_ReadSector)(unsigned  long sector, unsigned char * buffer) = MMC_SD_ReadSingleBlock;//device read
   
///FAT初始化
unsigned char FAT_Init()
{       unsigned long     x;
	
	unsigned  long   *p; 
	unsigned int     *rscnt;//保留扇区数
	unsigned long     *fatsz;//FAT大小
	if(FAT_ReadSector(0,bf))return 1; //读出启动扇区
	p=&bf[454];         //取出分区启动扇区地址  
	x=*p;
	FAT_ReadSector(x,bf); //读分区的启动扇区
	secpclus=bf[13];    //每籁的扇区数
	rscnt=&bf[14];       //保留扇区
	fatsz=&bf[36];       //FAT大小
	firstrodirclus=bf[44];//根目录的首籁号0
	fr_fatsec=x+(*rscnt);    //FAT首扇区
	rodir=fr_fatsec+(*fatsz)*2; //算出根目录  
	
	
	return 0;
}
     

//读一个簇中的一个扇区
unsigned char FAT_LoadPartCluster(unsigned long cluster,unsigned part,unsigned char * buffer)
{
	unsigned  long sector;
	sector=rodir+(unsigned  long)(cluster-2)*(unsigned  long)secpclus;//算出扇区
	if(MMC_SD_ReadSingleBlock(sector+part,buffer))return 1;
	else return 0;
}




//读下一簇簇号
unsigned long FAT_NextCluster(unsigned long cluster)
{       unsigned long *x;
	unsigned  long sector;
	unsigned  long offset; 
	offset = cluster/128;
	if(cluster<2){return 0x0ffffff8;}
	sector=fr_fatsec+offset;
	if(FAT_ReadSector(sector,bf))return 0x0ffffff8;//读FAT表
		offset=cluster%128;//因为籁号大于128时就会跨扇区
		x=&bf[offset*4];
	return *x;
}





//----------------------------------------
//读下一簇簇号
unsigned long FAT_NextCluster1(unsigned long cluster)
{       unsigned long *x;
        unsigned char r1,i;
        unsigned int retry=0;
        unsigned char  buf[4];
	unsigned  long sector;
	unsigned  long offset; 
	offset = cluster/128;
	//if(cluster<2){return 0x0ffffff8;}
	sector=(fr_fatsec+offset)*512;
	offset=cluster%128;//因为籁号大于128时就会跨扇区 
	sector=sector+offset*4;
	
	MMC_SD_SendCommand(16, 4);
	r1 = MMC_SD_SendCommand(17, sector);
	if(r1 != 0x00)
		return r1;  
		PORTB.2=0  ;  //cs=0
	//等数据的开始	
	while(SPI_WriteByte(0xff) != 0xfe)if(retry++ > 1000){PORTB.2=1;return 1;}
         for(i=0; i<4; i++)//读4个数据	
	{
		buf[i] = SPI_WriteByte(0xff);
	}
        x=buf;
	SPI_WriteByte(0xff);//伪crc
	SPI_WriteByte(0xff);
	MMC_SD_SendCommand(16,512);
	PORTB.2=1; //cs=1
        
        
	return *x;
}




//-------------------------


///////////////////////////////////////

//search the file , when *count = 0 it will bring the number whole songs, when *cout != 0 the *MusicInfo will bring the infomation of the file
unsigned char Search(unsigned  int *Count)//当COUNT为零时，有它带回这个目录下总共有多少首音乐
{      unsigned long      tempclust,sector; 
        unsigned char      cnt;
        unsigned int     offset;
        unsigned int     i=0;    
        unsigned int    *p; 
                                       
	tempclust=firstrodirclus;
		while(1)
		{       sector=rodir+(unsigned  long)(tempclust-2)*(unsigned  long)secpclus;//算出扇区
			for(cnt=0;cnt<secpclus;cnt++)//读一个籁
			{
				if(FAT_ReadSector(sector+cnt,bf)){return 1;}
				
				for(offset=0;offset<512;offset+=32)//扇区内遍历
				{      
				     if((bf[offset] !=0)&(bf[offset] !='.')&(bf[offset] !=0xe5)&(bf[offset+11]!=0x0f))
					{    
						if((bf[offset+8] == 'W')&&(bf[offset+9] == 'A')&&(bf[offset+10] == 'V'))
						{
	 
	                                        p=&bf[offset+20]; 
	                                        filefirstclus=*p;
	                                        //TransmitByte(filefirstclus);
	                                        filefirstclus=filefirstclus<<16;
	                                        p=&bf[offset+26]; 
	                                        filefirstclus=(filefirstclus+*p);
						p=&bf[offset+28];
						filesize=*p;
						i++;
						if(i==*Count){return 0;}	
						}
			
					}
				}
			}
			
			tempclust=FAT_NextCluster(tempclust);//next cluster
			if(tempclust == 0x0fffffff || tempclust == 0x0ffffff8 )break;
		}
	
	if(*Count==0)*Count=i;
	return 0;
}