请教一下文件系统学习的问题

tao475824827

我想学习一下文件系统fatfs，看了些资料，准备实际动手操作一下，实现SD卡的操作，是不是这样一个模块就够了？

我看了这个模块配套的程序，感觉不是像网上说的那种 移植了文件系统的那样子啊。
并没有跑文件系统啊？

我买这个对么？
是不是说，这个只是测试了一下和SD卡的通信正常？如果需要对SD卡文件进行操作，还需要移植了文件系统才行？


附上程序，大家可以简单一看，只有这一个c文件

[mw_shl_code=c,true] [/mw_shl_code] [mw_shl_code=c,true]/* * SD模块测试程序 * * 用途：SD模块测试程序 * */ #include "REG52.H" ////////////////////////****************/ unsigned char *SDInfo1="SD Init Success."; unsigned char *SDInfo2="SD Init Fail."; unsigned int xdata ReadBuffer[128] ; unsigned int xdata WriteBuffer[128] ; unsigned int BlockSize; unsigned long int BlockNR; //sbit sd_clk=P3^2; //sbit sd_cse=P3^0; //sbit sd_dai=P3^3; //Do //sbit sd_dao=P3^1; //DI sbit sd_cse=P1^0; sbit sd_dao=P1^1;//DI sbit sd_clk=P1^2; sbit sd_dai=P1^3;//Do void Delay5us() { unsigned char a=0; for(a=0;a<40;a++) ; } //******************************************** void SD_2Byte_Write(unsigned int IOData) { unsigned char BitCounter; for (BitCounter=0;BitCounter<16;BitCounter++) { sd_clk=0;//CLK Low if(IOData&0x8000)//If the MSB of IOData is 1, then Do=1, else Do=0. sd_dao=1;//Do High else sd_dao=0;//Do Low sd_clk=1;//CLK High Delay5us(); IOData=IOData<<1;//Because the MSB is transmitted firstly, shift to next lower bit. } } //******************************************** void SD_Write(unsigned int IOData) { unsigned char BitCounter; IOData=IOData<<8; for (BitCounter=0;BitCounter<8;BitCounter++) { sd_clk=0;//CLK Low if(IOData&0x8000)//If the MSB of IOData is 1, then Do=1, else Do=0. sd_dao=1;//Do High else sd_dao=0;//Do Low sd_clk=1;//CLK High Delay5us(); IOData=IOData<<1;//Because the MSB is transmitted firstly, shift to next lower bit. } } //******************************************** unsigned int SD_2Byte_Read() { unsigned int Buffer; unsigned char BitCounter; Buffer=0; for (BitCounter=0;BitCounter<16;BitCounter++) { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Buffer=Buffer<<1;//Because the MSB is transmitted firstly, shift to next lower bit. //Because the LSB will be damaged, we can not put this line under next line. if(sd_dai) Buffer++;//If SPI_Din=1 then the LSB_of_Buffer=1. } return Buffer; } //******************************************** unsigned int SD_Read() { unsigned int Buffer; unsigned char BitCounter; Buffer=0xffff; for (BitCounter=0;BitCounter<8;BitCounter++) { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Buffer=Buffer<<1;//Because the MSB is transmitted firstly, shift to next lower bit. //Because the LSB will be damaged, we can not put this line under next line. if(sd_dai) Buffer++;//If SPI_Din=1 then the LSB_of_Buffer=1. } return Buffer; } //******************************************** unsigned int SD_CMD_Write(unsigned int CMDIndex,unsigned long CMDArg,unsigned int ResType,unsigned int CSLowRSV)//ResType:Response Type, send 1 for R1; send 2 for R1b; send 3 for R2. { //There are 7 steps need to do.(marked by [1]-[7]) unsigned int temp,Response,Response2,CRC,MaximumTimes; Response2=0; MaximumTimes=10; CRC=0x0095;//0x0095 is only valid for CMD0 if (CMDIndex!=0) CRC=0x00ff; sd_cse=0;//[1] CS Low SD_2Byte_Write(((CMDIndex|0x0040)<<8)+(CMDArg>>24));//[2] Transmit Command_Index & 1st Byte of Command_Argument. SD_2Byte_Write((CMDArg&0x00ffff00)>>8); //[2] 2nd & 3rd Byte of Command_Argument SD_2Byte_Write(((CMDArg&0x000000ff)<<8)+CRC); //[2] 4th Byte of Command_Argument & CRC only for CMD0 sd_dao=1;//[3] Do High //[3] Restore Do to High Level for (temp=0;temp<8;temp++)//[4] Provide 8 extra clock after CMD { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } switch (ResType)//[5] wait response { case 1://R1 { do Response=SD_Read(); while (Response==0xffff); break; } case 2://R1b { do Response=SD_Read(); while (Response==0xffff);//Read R1 firstly do Response2=SD_Read()-0xff00; while (Response2!=0);//Wait until the Busy_Signal_Token is non-zero break; } case 3: Response=SD_2Byte_Read();break;//R2 } if (CSLowRSV==0) sd_cse=1;//[6] CS High (if the CMD has data block response CS should be kept low) for (temp=0;temp<8;temp++)//[7] Provide 8 extra clock after card response { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } return Response; } //******************************************** unsigned int SD_Reset_Card() { unsigned int temp,MaximumTimes; MaximumTimes=10; for (temp=0;temp<80;temp++)//Send 74+ Clocks { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } return SD_CMD_Write(0x0000,0x00000000,1,0);//Send CMD0 } //******************************************** unsigned int SD_Initiate_Card()//Polling the card after reset { unsigned int temp,Response,MaximumTimes; MaximumTimes=50; for(temp=0;temp<MaximumTimes;temp++) { Response=SD_CMD_Write(0x0037,0x00000000,1,0);//Send CMD55 Response=SD_CMD_Write(0x0029,0x00000000,1,0);//Send ACMD41 if (Response==0xff00) temp=MaximumTimes; } return Response; } //******************************************** unsigned int SD_Get_CardInfo()//Read CSD register { unsigned int temp,Response,MaximumTimes; MaximumTimes=50; for(temp=0;temp<MaximumTimes;temp++) { Response=SD_CMD_Write(9,0x00000000,1,1);//Send CMD9 if (Response==0xff00) temp=MaximumTimes; } for (temp=0;temp<8;temp++)//Provide 8 clock to romove the first byte of data response (0x00fe) { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } for (temp=0;temp<8;temp++) ReadBuffer[temp]=SD_2Byte_Read();//Get the CSD data for (temp=0;temp<16;temp++)//Provide 16 clock to remove the last 2 bytes of data response (CRC) { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } sd_cse=1;//CS_High() for (temp=0;temp<8;temp++)//Provide 8 extra clock after data response { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } BlockNR=((ReadBuffer[3]<<2)&0x0fff)+((ReadBuffer[4]>>14)&0x0003)+1;//Calcuate MULT BlockNR=BlockNR*(0x0002<<(((ReadBuffer[4]<<1)&0x0007)+((ReadBuffer[5]>>15)&0x0001)+1));//Calcuate Block_Number return Response; } //******************************************** unsigned int SD_Overall_Initiation() { unsigned int Response,Response_2; Response=0x0000; Response_2=0xff00; sd_dao=1;//[1] Do High //[1] Do must be High when there is no transmition do Response=SD_Reset_Card();//[2] Send CMD0 while (Response!=0xff01); if (Response!=0xff01) Response_2+=8; //Response=SD_CMD_Write(8,0x00000000,1,0);//Send CMD8 Response=SD_Initiate_Card();//[3] Send CMD55+ACMD41 if (Response==0xff00) ; else { Response_2+=4; ; } do Response=SD_Get_CardInfo();//[4] Read CSD while (Response!=0xff00); if (Response==0xff01) Response_2+=2; return Response_2; // 0000|0000||0000|0000 Response_2 // |||_CSD Fail // ||__CMD55+ACMD41 Fail // |___CMD0 Fail } //******************************************** unsigned int SD_Get_CardID()//Read CID register { unsigned int temp,Response,MaximumTimes; MaximumTimes=10; for(temp=0;temp<MaximumTimes;temp++) { Response=SD_CMD_Write(10,0x00000000,1,1);//Send CMD9 if (Response==0xff00) temp=MaximumTimes; } for (temp=0;temp<8;temp++)//Provide 8 clock to romove the first byte of data response (0x00fe) { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } for (temp=0;temp<8;temp++) ReadBuffer[temp]=SD_2Byte_Read();//Get the CID data for (temp=0;temp<16;temp++)//Provide 16 clock to remove the last 2 bytes of data response (CRC) { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } sd_cse=1;//CS_High() for (temp=0;temp<8;temp++)//Provide 8 extra clock after data response { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } return Response; } //******************************************** unsigned int Read_Single_Block(unsigned long int BlockAddress) { unsigned int temp,Response,MaximumTimes; MaximumTimes=10; if (BlockAddress>BlockNR) return 0xff20;//whether BlockAddress out of range? for(temp=0;temp<MaximumTimes;temp++) { Response=SD_CMD_Write(17,BlockAddress,1,1);//Send CMD17 if (Response==0xff00) temp=MaximumTimes; } while (SD_Read()!=0xfffe) {;} //这里为了使只有512byte的单片机能够读写SD卡，特意节省了RAM的使用量，每次读写只有两个重复的128byte //如果您使用的单片机拥有1K以上的RAM请将"%128"去掉 for (temp=0;temp<256;temp++) ReadBuffer[temp%128]=SD_2Byte_Read();//Get the readed data for (temp=0;temp<16;temp++)//Provide 16 clock to remove the last 2 bytes of data response (CRC) { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } sd_cse=1;//CS_High() for (temp=0;temp<8;temp++)//Provide 8 extra clock after data response { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } return Response; } //******************************************** unsigned int Write_Single_Block(unsigned long int BlockAddress) { unsigned int temp,Response,MaximumTimes; MaximumTimes=10; if (BlockAddress>BlockNR) return 0xff20;//whether BlockAddress out of range? for(temp=0;temp<MaximumTimes;temp++) { Response=SD_CMD_Write(24,BlockAddress,1,1);//Send CMD24 if (Response==0xff00) temp=MaximumTimes; } for (temp=0;temp<8;temp++)//Provide 8 extra clock after CMD response { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } SD_Write(0x00fe);//Send Start Block Token //这里为了使只有512byte的单片机能够读写SD卡，特意节省了RAM的使用量，每次读写只有两个重复的128byte //如果您使用的单片机拥有1K以上的RAM请将"%128"去掉 for (temp=0;temp<256;temp++) SD_2Byte_Write(WriteBuffer[temp%128]);//Data Block SD_2Byte_Write(0xffff);//Send 2 Bytes CRC Response=SD_Read(); while (SD_Read()!=0xffff) {;} sd_cse=1;//CS_High() for (temp=0;temp<8;temp++)//Provide 8 extra clock after data response { sd_clk=0;//CLK Low Delay5us(); sd_clk=1;//CLK High Delay5us(); } return Response; } /* 串行通信初始化*/ void UartInit() { SCON = 0x50; // uart 模式1 (8 bit), REN=1； TMOD = TMOD | 0x20 ; // 定时器1 模式2； // TH1 = 0xF7; // 9600 Bds at 32MHz // TL1 = 0xF7; TH1 = 0xFD; // 9600 Bds at 11.059MHz TL1 = 0xFD; // TH1 = 0xFA; // 9600 Bds at 22.1184MHz // TL1 = 0xFA; ES = 1; //允许uart中断； EA = 1; //允许CPU中断； TR1 = 1; //运行定时器1： } void send_char_com(unsigned char ch) { SBUF=ch; while(TI==0); TI=0; } //向串口发送一个字符串 void send_string_com(unsigned char *str,unsigned int len) { unsigned char k=0; do { send_char_com(*(str + k)); k++; } while(k <len); } main() { unsigned int Data,M_Response; unsigned char i; //初始化要写入的数据 for(i=0;i<128;i++) { if (i < 64) { WriteBuffer=0x4141; } else { WriteBuffer=0x4242; } } UartInit(); TI = 0; M_Response=0x0000; M_Response=SD_Overall_Initiation(); M_Response=SD_CMD_Write(16,512,1,0); Data=SD_Get_CardID(); Write_Single_Block(0x0000); Read_Single_Block(0x0000); for(i=0; i<128; i++) { send_char_com(ReadBuffer>>8) ; //向串口发送高8位数据 send_char_com(ReadBuffer ) ; } while(1); } [/mw_shl_code]

正点原子

这就是个SD卡的接口而已，就是硬件。
软件你得自己去写