fat.c

基于ATmega64的MP3程序

//ICC-AVR application builder : 2005-11-12 17:11:59
// Target : M16
// Crystal: 8.0000Mhz
// copyright:鲁军波(endylu)
// www.shop34612283.taobao.com
// www.adembed.com
#include <iom16v.h>
#include <macros.h>
#include "main.h"

uint32 CHINALIB_point=0;
uint32 UNICODE_point=0;

extern MP3_INFO mp3_info;
extern FAT_INFO fat_info;

extern uint8 buffer[512];
extern uint8 MP3_all_number;
extern uint8 name_number;

//=======================================================================
uint8 FATinit(void)
{/*SD卡的变量*/
 
 uint16 BPB_BytePerSec;          //每扇区的字节数     512
  
 uint8  BPB_NumFATs;             //此卷中FAT表的份数；
 uint16 BPB_RootEntCnt;          //fat12/16根目录的目录项数；
 uint16 BPB_FATsz16;             //FAT12/FAT16一个FAT表占的扇区数（FAT32此项必须为0）；
 
 uint16 RootDirSectors;          //根目录所占的扇区数
 
 /*变量取值*/
 
 if(SD_read_sector2(0,&fat_info.Relative,1))
 	{
	return 1;
	}
 
 if(fat_info.Relative==0xEB)                       //判断有没有Relative Sectors
    fat_info.Relative=0;
 else
    SD_read_sector2(454,&fat_info.Relative,1);        //取Relative Sectors
 
 SD_read_sector2(((long)fat_info.Relative<<9)+11,buffer,13);   //取值

 
 BPB_BytePerSec=buffer[0]+((int)buffer[1]<<8);
 fat_info.BPB_SecPerClus=buffer[2];
 fat_info.BPB_RsvdSecCnt=buffer[3];
 BPB_NumFATs=buffer[5];

 BPB_RootEntCnt=buffer[6]+((int)buffer[7]<<8);
 BPB_FATsz16=buffer[11]+((int)buffer[12]<<8);
 
 /*计算根目录的首扇区号*/
 fat_info.Firstgengmulu=fat_info.Relative+fat_info.BPB_RsvdSecCnt+BPB_FATsz16*BPB_NumFATs;
 
 /*计算FAT16根目录所占的扇区数*/
 RootDirSectors=(((long)BPB_RootEntCnt<<5)+(BPB_BytePerSec-1) )/BPB_BytePerSec;
 /*计算簇2的首扇区*/
 fat_info.FirstDateSecter=fat_info.Relative+fat_info.BPB_RsvdSecCnt+((long)BPB_FATsz16*BPB_NumFATs)+RootDirSectors;


 return 0;
}

//=======================================================================
void Mp3_number_Counter(void)
{
 uint8 Read_number;
 uint8 counter_over=0;
 uint16 mulu_Clus_number;
 
 mulu_Clus_number=fat_info.Firstgengmulu;

 while(!counter_over)
  {
   
   SD_start_read(mulu_Clus_number++);
   Read_number=16;
   while(Read_number--)
      {
	   
	   SD_get_date(buffer,32);  
       if((buffer[0]!=0XE5)&(buffer[8]==0x4D)&(buffer[9]==0x50)&(buffer[10]==0x33))
		 {
		   
		  MP3_all_number++;
		  }
	   else if(buffer[0]==0)
	     {
		  while(Read_number--)
		     {
			  
			  SD_get_date(buffer,32);
		      }
		  counter_over=1;
		  }
	  
	  }    
  }

}

//=======================================================================
void MP3_Directory(uint8 number)
{
 uint8 i,j;
 uint8 counter;
 uint16 Read_number;
 uint32 mulu_Clus_number;
 
 Read_number=0;
 counter=number;
 mp3_info.Name_number=0;
 mulu_Clus_number=fat_info.Firstgengmulu;
 mulu_Clus_number=mulu_Clus_number<<9;
 
 
 while(counter)
 {
  SD_read_sector2(mulu_Clus_number+((long)(Read_number++)<<5),buffer,32);

  if(counter>1)
    {if((buffer[0]!=0XE5)&(buffer[8]==0x4D)&(buffer[9]==0x50)&(buffer[10]==0x33))
	   counter--; 
	}
  else if((buffer[0]!=0XE5)&(buffer[11]==0x0f)&(buffer[12]==0x00))
    {i=buffer[0]-0x40;
	 for(j=0;j<i;j++)
	     {
		 SD_read_sector2(mulu_Clus_number+((long)(Read_number++)<<5),buffer+(((int)j+1)<<5),32);
		
		 }
     if((buffer[((int)i<<5)+8]==0x4D)&(buffer[((int)i<<5)+9]==0x50)&(buffer[((int)i<<5)+10]==0x33))
	     { //处理数据了。
		  mp3_info.DIR_FstClusL[0]=buffer[((int)i<<5)+26];
	      mp3_info.DIR_FstClusL[1]=buffer[((int)i<<5)+27];
	   
	      //mp3_info.DIR_Filesize[0]=buffer[32*i+28];
	      mp3_info.DIR_Filesize[0]=buffer[((int)i<<5)+29];
	      mp3_info.DIR_Filesize[1]=buffer[((int)i<<5)+30];
	      //mp3_info.DIR_Filesize[3]=buffer[32*i+31];
			  
			  
		  if((UNICODE_point>0)&(CHINALIB_point>0))
		    {Read_number=0;
			 while(i--)
			  {
			   for(j=0;j<10;j++)
			   buffer[300+Read_number++]=buffer[((int)i<<5)+j+1];
		       for(j=0;j<12;j++)
			   buffer[300+Read_number++]=buffer[((int)i<<5)+j+14];
			   for(j=0;j<4;j++)
			   buffer[300+Read_number++]=buffer[((int)i<<5)+j+28];
			   }
			  mp3_info.Name_number=MAX_NAME_LENGTH;
			  
			  for(j=0;j<mp3_info.Name_number;j++)
			     {
				  if((buffer[300+j*2]==0x2E)&(buffer[300+j*2+6]==0x33))     
                      mp3_info.Name_number=j;
				  for(i=0;i<31;i++)
				   {
				    SD_read_sector2(UNICODE_point+((int)i<<8),buffer,256);
					for(Read_number=0;Read_number<128;Read_number++)
					   {
					    if((buffer[Read_number<<1]==buffer[300+j*2])&(buffer[(Read_number<<1)+1]==buffer[300+j*2+1]))
					      {
						   mp3_info.NAME[j]=Read_number+((int)i<<7);
						   i=40;
						   break;
						  }
						}
				    }
				   if(i!=41)
			          mp3_info.NAME[j]=0x000A;     //OFFSET.0x3e是*
			      }
			}
		  counter--;
		 }
	 }
  else if((buffer[0]!=0XE5)&(buffer[8]==0x4D)&(buffer[9]==0x50)&(buffer[10]==0x33))
	 {//处理数据了。
              //mp3_info.Name_number=0;
			  
			  mp3_info.DIR_FstClusL[0]=buffer[26];
	          mp3_info.DIR_FstClusL[1]=buffer[27];
	   
	          //mp3_info.DIR_Filesize[0]=buffer[28];
	          mp3_info.DIR_Filesize[0]=buffer[29];
	          mp3_info.DIR_Filesize[1]=buffer[30];
	          //mp3_info.DIR_Filesize[3]=buffer[31];
			  
	  counter--;
	 }  
	
 }

}

//=======================================================================
void DAT_Directory(void)
{

 uint16 Read_number;
 uint32 mulu_Clus_number;
 
 Read_number=0;
 mulu_Clus_number=fat_info.Firstgengmulu;
 mulu_Clus_number<<=9;
 
 while(1)
 {
  SD_read_sector2(mulu_Clus_number+((long)(Read_number++)<<5),buffer,32);
  if((buffer[0]!=0XE5)&(buffer[8]==0x44)&(buffer[9]==0x41)&(buffer[10]==0x54))
	{ 
	 if((buffer[0]==0X55)&(buffer[1]==0x4e)&(buffer[2]==0x49))
	   {UNICODE_point=(((long)buffer[27]<<8)+buffer[26]-2)*(fat_info.BPB_SecPerClus)+fat_info.FirstDateSecter; //簇的头扇区号 
	    UNICODE_point<<=9;
	   }
	 else if((buffer[0]==0X43)&(buffer[1]==0x48)&(buffer[2]==0x49))
	   {CHINALIB_point=(((long)buffer[27]<<8)+buffer[26]-2)*(fat_info.BPB_SecPerClus)+fat_info.FirstDateSecter; //簇的头扇区号 
	    CHINALIB_point<<=9;
	   }
	}
  if(buffer[0]==0x00)
     break;
 }
}