原创 SD卡底层SPI操作源码+ZLG-SD源码包

 2009-3-13 22:45  4403 4 6 分类: 通信

https://static.assets-stash.eet-china.com/album/old-resources/2009/3/13/87669dea-fc53-4cba-8d0d-e1fc25c795ff.rar

#include"lpc214x.h"
#include "head.h" //定义一些数据结构

#define SD_Disable() IO0SET |= 1 << 20 //SD Chip Select Pin is P0.7
#define SD_Enable() IO0CLR |= 1 << 20

INT8U CMD[]={0x40, 0x00, 0x00, 0x00, 0x00, 0x95};

INT8U SPI_RW(INT8U data)
{
SSPDR = data;
while((SSPSR & 0x01) == 0);
return(SSPDR);
}

void spi_init (void)
{

INT32U i;

   /* SSEL is GPIO, output set to high. */
   IODIR0 |= 1<<20;
   IOSET0   = 1<<20;
   /* SCK1, MISO1, MOSI1 are SSP pins. */
   PINSEL1 = (PINSEL1 & ~0x000003FC) | 0x000000A8;

   /* Enable SPI in Master Mode, CPOL="1", CPHA="1" (Clock low-active). */
   SSPCR0 = 0x00C7;
   SSPCR1 = 0x0002;
   SSPCPSR = 0x7E;

   /* Send SPI Command with card not selected at 400 KBit. */
   for (i = 0; i < 16; i++) {
      SPI_RW (0xFF);
   }

/* Enable SSP auto select. */
}

INT8U Write_Command_SD(INT8U *CMD)
{
    INT8U i = 0, response = 1, retry = 0;

    SD_Disable();
    SPI_RW(0xff);
    SD_Enable();
    for(i = 0; i < 0x06; i++)
    {
    SPI_RW(*CMD++);
    }

    SPI_RW(0xff);

    do
    {
    response = SPI_RW(0xff);
        retry++;
    }
    while((response== 0xff) && (retry < 100));
    return(response);
}

INT8U SD_write_sector(INT32U Number_Sector, INT8U* Buffer)
{
    INT8U response,response_1,retry;
    INT16U i;
    //Command 24 is a writing blocks command for SD/SD-Card.
    INT8U CMD[] = {0x58, 0x00, 0x00, 0x00, 0x00, 0xFF};
INT8U CMD_SET_BLOCKLEN[]={0x50,0x00,0x00,0x02,0x00,0xFF};   //设定读取块大小
retry = 0;
SSPCPSR = 0x7E;
    do
    { //Retry 100 times to send command.
    response = Write_Command_SD(CMD_SET_BLOCKLEN);
       if(++retry >= 100)
        return(1); //block read Error!
    }
    while(response != 0);

SPI_RW(0XFF);


    Number_Sector <<= 9; //addr = addr * 512

    CMD[1] = ((Number_Sector & 0xFF000000) >> 24 );
    CMD[2] = ((Number_Sector & 0x00FF0000) >> 16 );
    CMD[3] = ((Number_Sector & 0x0000FF00) >> 8 );
    CMD[4] = ((Number_Sector & 0x000000FF) >> 0) ;
    //Send Command CMD24 to SD/SD-Card (Write 1 Block/512 Bytes)
    retry = 0;
    do
    { //Retry 100 times to send command.
       response = Write_Command_SD(CMD);
       if(++retry >= 100)
       {
           return(1); //send commamd Error!
       }
    }
    while(response != 0);


//   for(i = 0; i < 20; i++)
       SPI_RW(0xff);

    //Send Start Byte to SD/SD-Card
    SPI_RW(0xfe);

    SSPCPSR = 0x04;
    //Now send real data Bolck (512Bytes) to SD/SD-Card
    for(i = 0; i < 512; i++)
       SPI_RW(* Buffer++); //send 512 bytes to Card

    //CRC-Byte
    SPI_RW(0xFF); //Dummy CRC
    SPI_RW(0xFF); //CRC Code
//    retry="0";

do
{
    response="SPI"_RW(0xFF);//Read Response
}
while(response==0xff);

    do
{
      response_1=SPI_RW(0xFF);
}
while(response_1!=0xFF);
    SD_Disable();
SPI_RW(0xff);
    if ((response&0x1f)!=0x05) return(1);

return(0);

}

INT8U SD_Read_Block(INT8U *CMD, INT8U *Buffer, INT16U Bytes)
{
    INT16U i;
    INT8U retry,response;
    INT16U Block_Len=0;
    INT8U CMD_SET_BLOCKLEN[]={0x50,0x00,0x00,0x00,0x00,0xFF};
    SSPCPSR = 0x7E;
    if(Bytes != Block_Len)
    {
        CMD_SET_BLOCKLEN[3] = (INT8U)((Bytes & 0x0000FF00) >> 8 );
    CMD_SET_BLOCKLEN[4] = (INT8U)((Bytes & 0x000000FF) >> 0 );

    retry = 0;
    do
    { //Retry 100 times to send command.
       response = Write_Command_SD(CMD_SET_BLOCKLEN);
        if(++retry >= 100)
           return(1); //block read Error!
    }
    while(response != 0);
    Block_Len = Bytes;
    }
    //Send reads a block Command CMD to SD/SD-Card
    retry = 0;
    do
    {
    response = Write_Command_SD(CMD);
        if(++retry >= 100)
        return(1); //block read Error!
    }
    while(response != 0);

    //Read Start Byte form SD/SD-Card (FEh/Start Byte)
//    while(SPI_RW(0xff) != 0xfe) ;
    retry="0";
    for(i=0;i<1000;i++)
{
     response="SPI"_RW(0xff);
   retry++;
   if(response==0xfe)
   i="1000";
   if(retry==1000)
   return(1);
}

SSPCPSR = 0x04;
    //Write blocks(normal 512Bytes) to SD/SD-Card
    for(i = 0; i < Bytes; i++)
    *Buffer++ = SPI_RW(0xff);

    //CRC-Byte
    SPI_RW(0xff);//CRC - Byte
    SPI_RW(0xff);//CRC - Byte

    SD_Disable();
    return(0);
}

SD_INIT()
{
INT8U retry, response;
INT16U i;

spi_init();
SD_Enable();

   for(i=0;i<250;i++)
__asm
{
NOP
}
for(i = 0; i < 0x0f; i++)
{
SPI_RW(0xff);
}
//Send Command CMD0 to SD/SD Card
retry = 0;
do
{ //retry 200 times to send CMD0 command

    response = Write_Command_SD(CMD);    //CMD0   响应为01
    retry++;
}
while((response != 1) && (retry < 200));

   retry="0";
   do
   {
        CMD[0]=0x77;
        CMD[5]=0x55;
        Write_Command_SD(CMD);                   //CMD55 响应为01
        CMD[0]=0X69;
        response="Write"_Command_SD(CMD);      //ACMD41   响应为00
   retry++;
   }
   while((response!=0)&&(retry<200)) ;
// return(response);
}

void SD_WRITE(INT8U* Buffer,INT32U Number_Sector)
{
   INT8U retry, response;
   retry="0";
do
{
      response="SD"_write_sector(Number_Sector,Buffer);
   retry++;
   }
   while((response!=0x00)&&(retry<20)) ;
}

void SD_READ(INT8U *Buffer, INT16U Bytes,INT32U Number_Sector)
{
   INT8U response,retry;
   INT8U CMD[]={0X51,0X00,0X00,0X00,0X00,0XFF};
   Number_Sector=Number_Sector<<9;
   CMD[1] = ((Number_Sector & 0xFF000000) >> 24 );
   CMD[2] = ((Number_Sector & 0x00FF0000) >> 16 );
   CMD[3] = ((Number_Sector & 0x0000FF00) >> 8 );
   CMD[4] = ((Number_Sector & 0x000000FF) >> 0) ;
   retry="0";
   do
   {
      response="SD"_Read_Block(CMD,Buffer,Bytes);
   retry++;
   }
   while((response!=0)&&(retry<100));
}