?? sdcmd.c
字號:
if (resp != 0)
return SD_ERR_CMD_RESP;
ret = SD_SendCmd(ACMD22, tmp, ACMD22_R, &resp); /* 讀取正確寫入的塊數命令 */
if (ret != SD_NO_ERR) /* command that read the numbers of block written correctly */
return ret;
if (resp != 0)
return SD_ERR_CMD_RESP; /* 響應錯誤 response is error */
ret = SD_ReadBlockData(4, tmp); /* 讀塊數 read the numbvers of block */
if (ret != SD_NO_ERR)
return ret;
*blocknum = (tmp[0] << 24) + (tmp[1] << 16) + (tmp[2] << 8) + tmp[3];
/* 轉換為32位 change to 32 bits */
return SD_NO_ERR; /* 返回執行成功 return perform sucessfully */
}
#endif
/*********************************************************
下面為一些數據傳輸函數
**********************************************************/
/********************************************************************************************************************
** 函數名稱: INT8U SD_ReadRegister() Name: INT8U SD_ReadRegister()
** 功能描述: 從SD卡讀取數據 Function: read data from SD card
** 輸 入: INT32U len : 長度 Input: INT32U len : length
INT8U *recbuf: 接收緩沖區 INT8U *recbuf: receive buffer
** 輸 出: 0: 正確 >0: 錯誤碼 Output: 0: right >0: error code
*********************************************************************************************************************/
uint8 SD_ReadRegister(uint32 len, uint8 *recbuf)
{
uint32 i = 0;
uint8 resp;
SPI_CS_Assert();
do{ /* 等待數據起始令牌 wait for data start token */
resp = SPI_RecByte();
i++;
}while((resp == 0xFF) && (i < SD_READREG_TIMEOUT));
if (i >= SD_READREG_TIMEOUT)
{
SPI_CS_Deassert();
return SD_ERR_TIMEOUT_READ; /* 超時, 返回錯誤 timeout, return error */
}
if (resp != SD_TOK_READ_STARTBLOCK)
{ /* 不是收到數據起始令牌 not receive data start token */
recbuf[0] = resp;
i = 1; /* 還有len - 1個字節要接收 still len - 1 bytes will be received */
}
else
i = 0; /* 收到數據起始令牌,還有len個字節要接收 received data start token,still len bytes will be received */
for (; i < len; i++)
recbuf[i] = SPI_RecByte(); /* 接收數據 receive data */
i = SPI_RecByte();
i = (i << 8) + SPI_RecByte(); /* 讀取16位CRC get 16-bit CRC */
#if SD_CRC_EN
if (i != SD_GetCRC16(recbuf, len))
{ /* CRC校驗錯誤 CRC check is error */
SPI_CS_Deassert();
SPI_SendByte(0xFF);
return SD_ERR_DATA_CRC16; /* 返回RCR16錯誤 return error of CRC16 */
}
#endif
SPI_SendByte(0xFF); /* 返回之前發送8個clock clock out 8 clk before return */
SPI_CS_Deassert();
return SD_NO_ERR;
}
/*******************************************************************************************************************
** 函數名稱: INT8U SD_ReadBlockData() Name: INT8U SD_ReadBlockData()
** 功能描述: 從SD卡中讀取數據塊 Function: read block data from sd card
** 輸 入: INT32U len : 長度 Input: INT32U len : length
INT8U *recbuf : 接收緩沖區 INT8U *recbuf : the buffer of receive
** 輸 出: 0: 正確 >0: 錯誤碼 Output: 0: right >0: error code
*******************************************************************************************************************/
uint8 SD_ReadBlockData(uint32 len, uint8 *recbuf)
{
uint8 tmp;
uint32 i = 0;
SPI_CS_Assert();
do
{ /* 等待接收數據開始令牌0xFE wait for receiving data start token 0xFE */
tmp = SPI_RecByte();
i++;
}while((tmp == 0xFF) && (i < sds.timeout_read));
if (i >= sds.timeout_read)
{
SPI_CS_Deassert();
return SD_ERR_TIMEOUT_READ; /* 返回讀超時錯誤碼 return error timeout error code of reading */
}
if (tmp != SD_TOK_READ_STARTBLOCK) /* 塊讀開始令牌錯誤 read start block token is error */
{
SPI_SendByte(0xFF);
SPI_CS_Deassert();
return SD_ERR_DATA_START_TOK;
}
for (i = 0; i < len; i++)
recbuf[i] = SPI_RecByte(); /* 接收數據 receive data */
i = SPI_RecByte();
i = (i << 8) + SPI_RecByte(); /* 讀取16位CRC get 16-bit CRC */
#if SD_CRC_EN
if (i != SD_GetCRC16(recbuf, len))
{ /* CRC校驗錯誤 CRC check is error */
SPI_SendByte(0xFF);
SPI_CS_Deassert();
return SD_ERR_DATA_CRC16; /* 返回CRC16錯誤 return error of CRC16 */
}
#endif
SPI_SendByte(0xFF);
SPI_CS_Deassert();
return SD_NO_ERR; /* 返回函數執行成功 return function perform sucessfully */
}
/*******************************************************************************************************************
** 函數名稱: INT8U SD_WriteBlockData() Name: INT8U SD_WriteBlockData()
** 功能描述: 向sd卡寫數據塊 Function: write block data to sd card
** 輸 入: INT8U bmulti : 是否為多塊操作1:是0:否 Input: INT8U bmulti : multi blocks operate 1:Y 0:N
INT32U len : 長度 INT32U len : length
INT8U *sendbuf: 發送緩沖區 INT8U *sendbuf : the buffer of send
** 輸 出: 0: 正確 >0: 錯誤碼 Output: 0: right >0: error code
********************************************************************************************************************/
uint8 SD_WriteBlockData(uint8 bmulti, uint32 len, uint8 *sendbuf)
{
uint16 i;
uint8 tmp;
SPI_CS_Assert();
SPI_SendByte(0xFF); /* 開始發送數據之前發送8個clock clock out 8 clk before start */
if (bmulti == 1)
SPI_SendByte(SD_TOK_WRITE_STARTBLOCK_M); /* 寫多塊開始令牌 start token of write multi blocks */
else
SPI_SendByte(SD_TOK_WRITE_STARTBLOCK); /* 寫單塊開始令牌 start token of write single block */
for (i = 0; i < len; i++)
SPI_SendByte(sendbuf[i]); /* 發送數據 send data */
#if SD_CRC_EN
i = SD_GetCRC16(sendbuf,len); /* 計算CRC16 calculate CRC16 */
#endif
SPI_SendByte((i >> 8) & 0xFF);
SPI_SendByte(i & 0xFF); /* 發送CRC16校驗碼 send CRC16 check code */
tmp = SPI_RecByte();
if ((tmp & SD_RESP_DATA_MSK) != SD_RESP_DATA_ACCETPTED)
{
SPI_SendByte(0xFF); /* 返回之前發送8個clock clock out 8 clk before return */
SPI_CS_Deassert();
return SD_ERR_DATA_RESP; /* 數據響應錯誤 data response error */
}
SPI_CS_Deassert();
if (SD_WaitBusy(SD_WAIT_WRITE) != SD_NO_ERR)
return SD_ERR_TIMEOUT_WRITE; /* 寫入超時 write time out */
else
return SD_NO_ERR; /* 寫入正確 write right */
}
/*******************************************************************************************************************
** 函數名稱: void SD_StopMultiToken() Name: void SD_StopMultiToken(void)
** 功能描述: 發送多塊寫停止令牌 Function: send the token that stop multiple block write
** 輸 入: 無 Input: NULL
** 輸 出: 無 Output: NULL
********************************************************************************************************************/
void SD_StopMultiToken(void)
{
SPI_CS_Assert();
SPI_SendByte(0xFF); /* 先發送8個clock send 8 clock first */
SPI_SendByte(SD_TOK_STOP_MULTI); /* 發送停止數據傳輸令牌 send stop transmission token */
SPI_RecByte();
SPI_CS_Deassert();
}
/********************************************************************************************************************
** 函數名稱: void SD_WaitBusy() Name: void SD_WaitBusy()
** 功能描述: 查詢SD卡是否處于忙狀態 Function: poll SD Card wheather it is busy
** 輸 入: INT32U waittype: 超時類型 Input: INT32U timeout: time out type
** 輸 出: 0: 未超時 >0: 錯誤碼 Output: 0: not time out > 0: error code
*********************************************************************************************************************/
uint8 SD_WaitBusy(uint8 waittype)
{
uint32 timeout, i = 0;
uint8 tmp;
if (waittype == SD_WAIT_WRITE)
timeout = sds.timeout_write;
else
timeout = sds.timeout_erase;
SPI_CS_Assert();
do
{ /* 等待忙結束 wait for being busy end */
tmp = SPI_RecByte();
i++;
}while ((tmp != 0xFF) && (i < timeout)); /* 忙時收到的值為0xFF always receive 0xFF when card is busy */
SPI_CS_Deassert(); /* 有錯 */
if(i < timeout)
return SD_NO_ERR; /* 返回0,表示沒超時 return 0 indicate that operation is not time out */
else
return SD_ERR_TIMEOUT_WAIT; /* 返回錯誤碼,表示超時 return error code indicate that operation is time out */
}
/********************************************************************************************************************
** 函數名稱: void SD_SPIDelay() Name: void SD_SPIDelay()
** 功能描述: SPI總線延時 Function: SPI Bus delay
** 輸 入: INT8U value: 延時值,不超過255 Input: INT8U value : delay value,do not beyond 255
** 輸 出: 無 Output: NULL
*********************************************************************************************************************/
void SD_SPIDelay(uint8 value)
{
uint8 i;
for (i = 0; i < value; i++)
SPI_SendByte(0xFF); /* 發送0xFF clock out 0xFF */
}
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