sd_card.rar_SD CARD pic_pic18f4520_pic18f4520 mcc18_读SD卡

/*******************************************************************/ /* FAT diriver for MP3 Player */ /* */ /* Platform : MAPLAB + MCC18 */ /* optimize : Enable All */ /* Author : bozai(Zhang Qibo) */ /* E-mail : sudazqb@163.com */ /* MSN : zhangqibo_1985@hotmail.com */ /* Date : 2007-12-01 */ /*******************************************************************/ /*2007-12-01: migrate from AVR platform to PIC */ /*2007-11-09: now the songs may placed in any directory, but the */ /* total number of folder the card has should less than */ /* 127 for we use 512Bytes EEPROM to stored the info */ /*2007-10-08: fix a bug (but it never works), so stupid I am, */ /* take & as && */ /*2006-06-14: still the bug of FAT */ /*2006-05-04: fix bug of FAT init, add read capacity check */ /*******************************************************************/ #include"FAT.h" #include<p18cxxx.h> #include<stdio.h> extern unsigned char tmpBuf[512]; DWORD FirstDirClust; //first directory cluster DWORD FirstDataSector; // The first sector number of data WORD BytesPerSector; // Bytes per sector WORD FATsectors; // The amount sector a FAT occupied WORD SectorsPerClust; // Sector per cluster DWORD FirstFATSector; // The first FAT sector DWORD FirstDirSector; // The first Dir sector DWORD RootDirSectors; // The sector number a Root dir occupied DWORD RootDirCount; // The count of directory in root dir BYTE FAT32_Enable; BYTE (* FAT_ReadSector)(DWORD,BYTE *); BYTE (* FAT_WriteSector)(DWORD,BYTE *); //函数指针指向sd卡的读写函数 //function pointer to the sd card read & write single block //wirte sector are not use in this player BYTE (* FAT_ReadSector)(DWORD sector, BYTE * buffer)=MMC_SD_ReadSingleBlock;//device read BYTE (* FAT_WriteSector)(DWORD sector, BYTE * buffer)=MMC_SD_WriteSingleBlock;//device write extern struct FileInfoStruct FileInfo;//temporarily buffer for file information //FAT初始化，不含SD的初始化，用之前应先调用sd的初始化 unsigned char FAT_Init()//Initialize of FAT need initialize SD first { struct bootsector710 *bs = 0; struct bpb710 *bpb = 0; // struct partsector *ps = 0; struct partrecord *pr = 0; //BYTE buffer[512]; BYTE * buffer = tmpBuf; DWORD hidsec=0; DWORD Capacity; Capacity = MMC_SD_ReadCapacity(); if(Capacity<0xff)return 1; if(FAT_ReadSector(0,buffer))return 1; bs = (struct bootsector710 *)buffer; pr = (struct partrecord *)((struct partsector *)buffer)->psPart;//first partition hidsec = pr->prStartLBA;//the hidden sectors if(hidsec >= Capacity/512) { hidsec = 0; } else { if(FAT_ReadSector(pr->prStartLBA,buffer))return 1;//read the bpb sector bs = (struct bootsector710 *)buffer; if(bs->bsJump[0]!=0xE9 && bs->bsJump[0]!=0xEB) { hidsec = 0; if(FAT_ReadSector(0,buffer))return 1;//read the bpb sector bs = (struct bootsector710 *)buffer; } } if(bs->bsJump[0]!=0xE9 && bs->bsJump[0]!=0xEB)//对付没有bootsect的sd卡 //dead with the card which has no bootsect { return 1; } bpb = (struct bpb710 *)bs->bsBPB; if(bpb->bpbFATsecs)//detemine thd FAT type //do not support FAT12 { FAT32_Enable=0; //FAT16 FATsectors = bpb->bpbFATsecs;//FAT占用的扇区数 //the sectors number occupied by one fat talbe FirstDirClust = 2; } else { FAT32_Enable=1; //FAT32 FATsectors = bpb->bpbBigFATsecs;//FAT占用的扇区数 //the sectors number occupied by one fat talbe FirstDirClust = bpb->bpbRootClust; } BytesPerSector = bpb->bpbBytesPerSec;//每扇区字节数 SectorsPerClust = (BYTE)bpb->bpbSecPerClust;//每簇扇区数 FirstFATSector = bpb->bpbResSectors+hidsec;//第一个FAT表扇区 RootDirCount = bpb->bpbRootDirEnts;//根目录项数 RootDirSectors = (RootDirCount*32)>>9;//根目录占用的扇区数 FirstDirSector = FirstFATSector+bpb->bpbFATs*FATsectors;//第一个目录扇区 FirstDataSector = FirstDirSector+RootDirSectors;//第一个数据扇区 return 0; } //读一个簇中的一个扇区 //read one sector of one cluster, parameter part indicate which sector unsigned char FAT_LoadPartCluster(unsigned long cluster,unsigned part,BYTE * buffer) { DWORD sector; sector=FirstDataSector+(DWORD)(cluster-2)*(DWORD)SectorsPerClust;//calculate the actual sector number if(FAT_ReadSector(sector+part,buffer))return 1; else return 0; } //读下一簇簇号 //Return the cluster number of next cluster of file //Suitable for system which has limited RAM unsigned long FAT_NextCluster(unsigned long cluster) { //BYTE buffer[512]; BYTE * buffer = tmpBuf; DWORD sector; DWORD offset; if(FAT32_Enable)offset = cluster/128; else offset = cluster/256; if(cluster<2)return 0x0ffffff8; sector=FirstFATSector+offset;//calculate the actual sector if(FAT_ReadSector(sector,buffer))return 0x0ffffff8;//read fat table / return 0xfff8 when error occured if(FAT32_Enable) { offset=cluster%128;//find the position sector=((unsigned long *)buffer)[offset]; } else { offset=cluster%256;//find the position sector=((unsigned int *)buffer)[offset]; } return (unsigned long)sector;//return the cluste number } #if FIX_DIRECTORY //在给定目录下查找文件 //Find a item in the directory which specify by the parameter "cluster" //Return the start cluster number unsigned int FAT_FindItem(unsigned long cluster, BYTE *name, struct FileInfoStruct *FileInfo) { BYTE *buffer; DWORD tempclust; DWORD sector; unsigned char cnt; unsigned int offset; unsigned char i; struct direntry *item = 0; if((cluster==0) && (FAT32_Enable == 0))// root directory { buffer=tmpBuf;//apply memory if(buffer==0)return 1;//if failed for(cnt=0;cnt<RootDirSectors;cnt++) { if(FAT_ReadSector(FirstDirSector+cnt,buffer)){/*free(buffer);*/return 1;} for(offset=0;offset<512;offset+=32) { item=(struct direntry *)(&buffer[offset]); if((item->deName[0] != 0x00) && (item->deName[0] != 0xe5) && (item->deAttributes != 0x0f)) { for(i=0;i<11;i++) { if(buffer[offset+i]!=name[i])break; } if(i==11) { //return the parameter of the item FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care FileInfo->Size = item->deFileSize; FileInfo->Attr = item->deAttributes; FileInfo->Sector = FirstDirSector+cnt; FileInfo->Offset = offset; /*free(buffer);*/ return 0; } } } } /*free(buffer);*///release } else//other folders { tempclust=cluster; while(1) { sector=FirstDataSector+(DWORD)(tempclust-2)*(DWORD)SectorsPerClust;//calculate the actual sector number buffer=tmpBuf;//apply memory if(buffer==0)return 1;//if failed for(cnt=0;cnt<SectorsPerClust;cnt++) { if(FAT_ReadSector(sector+cnt,buffer)){/*free(buffer);*/return 1;} for(offset=0;offset<512;offset+=32) { item=(struct direntry *)(&buffer[offset]); if((item->deName[0] != 0x00) && (item->deName[0] != 0xe5) && (item->deAttributes != 0x0f)) { for(i=0;i<11;i++) { if(buffer[offset+i]!=name[i])break; } if(i==11) { FileInfo->StartCluster = item->deStartCluster + (((unsigned long)item->deHighClust)<<16);//don't care FileInfo->Size = item->deFileSize; FileInfo->Attr = item->deAttributes; FileInfo->Sector = sector+cnt; FileInfo->Offset = of