MMC卡读写C代码

// MMC commands
#define MMC_GO_IDLE_STATE 0
#define MMC_SEND_OP_COND 1
#define MMC_SEND_CSD 9
#define MMC_SEND_CID 10
#define MMC_SEND_STATUS 13
#define MMC_SET_BLOCKLEN 16
#define MMC_READ_SINGLE_BLOCK 17
#define MMC_WRITE_BLOCK 24
#define MMC_PROGRAM_CSD 27
#define MMC_SET_WRITE_PROT 28
#define MMC_CLR_WRITE_PROT 29
#define MMC_SEND_WRITE_PROT 30
#define MMC_TAG_SECTOR_START 32
#define MMC_TAG_SECTOR_END 33
#define MMC_UNTAG_SECTOR 34
#define MMC_TAG_ERASE_GROUP_START 35
#define MMC_TAG_ERARE_GROUP_END 36
#define MMC_UNTAG_ERASE_GROUP 37
#define MMC_ERASE 38
#define MMC_CRC_ON_OFF 59

#define R1_BUSY 128
#define R1_PARAMETER 64
#define R1_ADDRESS 32
#define R1_ERASE_SEQ 16
#define R1_COM_CRC 8
#define R1_ILLEGAL_COM 4
#define R1_ERASE_RESET 2
#define R1_IDLE_STATE 1

#define led1_off (PORTA|=(1<6))
#define led1_on (PORTA&=~(1<6))
#define led2_off (PORTA|=(1<5))
#define led2_on (PORTA&=~(1<5))

#define disable_mmc_cs (PORTB|=(1<0))
#define enable_mmc_cs (PORTB&=~(1<0))

unsigned char ram_data[512];

extern void LCD_write(unsigned char data,unsigned char dc);

/***********SPI初始化******************/
void SPI_masterinit(void)
{
//不中断 允许 主模式 fck/4
SPCR=0b01010000; //SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0

}

/***********SPI读取/写入****基础SPI传送命令******/
unsigned char SPI_tx_rx(unsigned char spi_data);
unsigned char SPI_tx_rx(unsigned char spi_data)
{
SPDR=spi_data;
while (!(SPSR&0x80));
return SPDR;
}
/***********MMC_sendCmd();*****基础传送命令*******/
unsigned char MMC_sendCmd(unsigned char cmd,unsigned char A31_24,unsigned char A23_16,unsigned char A15_8,unsigned char A7_0);
unsigned char MMC_sendCmd(unsigned char cmd,unsigned char A31_24,unsigned char A23_16,unsigned char A15_8,unsigned char A7_0)
{
signed char temp;
enable_mmc_cs;

SPI_tx_rx(cmd|0x40); //cmd"01xxxxxx"
SPI_tx_rx(A31_24);
SPI_tx_rx(A23_16);
SPI_tx_rx(A15_8);
SPI_tx_rx(A7_0);
SPI_tx_rx(0x95); //crc for cmd0

SPI_tx_rx(0xff); //one empty cycle

temp=SPI_tx_rx(0xff); //0=busy
//LCD_write(temp,1); //test point
if ((temp-0x80)>=0) //0b1xxxxxxx=err
{
temp=0xff;
while (SPI_tx_rx(0xff)==0);
// led1_on; //test point
}
else
if (cmd==MMC_SEND_STATUS) //如果是读状态命令
{
temp=SPI_tx_rx(0xff); //read STATUS
while (SPI_tx_rx(0xff)==0);
// led1_on;
}
else //是其他命令
{
while (SPI_tx_rx(0xff)==0);
// led1_on;
}
return temp;
}
/***********MMC_finish();***停止卡片******/
void MMC_finish(void)
{
disable_mmc_cs;
SPI_tx_rx(0xff);
}

/***********MMC_flush();*****丢弃几个字节*******/
void MMC_flush(unsigned char flush_num);
void MMC_flush(unsigned char flush_num)
{
unsigned char counter;
for (counter=0;counterMMC_finish();
}

/***********MMC_reset();***将MMC卡转到SPI模式****/
void MMC_reset(void)
{
unsigned char counter,mmc_response,lcd_add;
for (counter=0;counter<11;counter++) SPI_tx_rx(0xff);//80个时钟开始总线

mmc_response=MMC_sendCmd(MMC_GO_IDLE_STATE,0,0,0,0); //send cmd0
MMC_finish();

for (counter=0;counter<80;counter++) //失败尝试次数
{

mmc_response=MMC_sendCmd(MMC_SEND_OP_COND,0,0,0,0);
MMC_finish();

if (mmc_response==0) //切换到SPI成功
{
led2_on;
counter=81; //跳出失败尝试次数
}
else led1_on; //切换到SPI失败

}

}

/***********MMC_check();******测试卡是否正常为0***********/
unsigned char MMC_check(void);
unsigned char MMC_check(void)
{
unsigned char mmc_response;
mmc_response=MMC_sendCmd(MMC_SEND_STATUS,0,0,0,0); //send cmd
MMC_finish();
LCD_write(0x55,1); //test point
LCD_write(mmc_response&0x93,1); //test point
LCD_write(0x55,1); //test point
return (mmc_response&0x93);
}

/***********MMC_name();**获得卡的名字*****/
void MMC_name(void)
{
unsigned char counter,lcd_add,mmc_response=1;
mmc_response=MMC_sendCmd(MMC_SEND_CID,0,0,0,0);
while (mmc_response) //读到数据为0表示正常，就跳出
{
MMC_finish();
mmc_response=MMC_sendCmd(MMC_SEND_CID,0,0,0,0);
LCD_write(mmc_response,1); //test point
led1_on; //test point
// prog_flag=1; //错误标记
}
led1_off; //test point
for (counter=0;counter<26;counter++)
{
ram_data[counter]=SPI_tx_rx(0xff);
LCD_write(ram_data[counter],1); //test point
}
MMC_flush(8);
}

/***********MMC_capactity();******************/
unsigned long MMC_capactity(void);
unsigned long MMC_capactity(void)
{
unsigned char counter,lcd_add,mmc_response=1;
mmc_response=MMC_sendCmd(MMC_SEND_CSD,0,0,0,0);
while (mmc_response) //读到数据为0表示正常，就跳出
{
MMC_finish();
mmc_response=MMC_sendCmd(MMC_SEND_CID,0,0,0,0);
LCD_write(mmc_response,1); //test point
led1_on; //test point
// prog_flag=1; //错误标记
}
led1_off; //test point
for (counter=0;counter<26;counter++)
{
ram_data[counter]=SPI_tx_rx(0xff);
LCD_write(ram_data[counter],1); //test point
}
MMC_flush(8);

}