?? sdcmd.c
字號:
** 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
*********************************************************************************************************************/
INT8U SD_ReadRegister(INT32U len, INT8U *recbuf)
{
INT32U i = 0;
INT8U 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_SendByte(0xFF);
SPI_CS_Deassert();
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: 從卡中讀取數據塊 Function: read block data from 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
*******************************************************************************************************************/
INT8U SD_ReadBlockData(INT32U len, INT8U *recbuf)
{
INT8U tmp;
INT32U i = 0,timeout;
#if SD_UCOSII_EN
timeout = SD_UCOSII_SMALLWAIT; /* 很少的等待時間 small wait time */
#else
timeout = sds.timeout_read; /* 等待接收數據開始令牌最長時間 wait time that receive data start token */
#endif
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 < timeout));
#if SD_UCOSII_EN
if (i >= timeout)
{ /* 繼續等待(掛起任務) continue to wait(suspend task) */
timeout = sds.timeout_read;
i = 0;
do
{
OSTimeDly(1); /* 掛起該任務1 tick(suspend task 1 tick) */
tmp = SPI_RecByte();
i++;
}while((tmp == 0xFF) && (i < timeout));
}
#endif
if (i >= timeout)
{
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))
{
SPI_SendByte(0xFF); /* CRC校驗錯誤 CRC check is error */
SPI_CS_Deassert();
return SD_ERR_DATA_CRC16; /* 返回RCR16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: 向卡寫數據塊 Function: write block data to 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 NT8U *sendbuf : the buffer of send
** 輸 出: 0: 正確 >0: 錯誤碼 Output: 0: right >0: error code
********************************************************************************************************************/
INT8U SD_WriteBlockData(INT8U bmulti, INT32U len, INT8U *sendbuf)
{
INT16U i;
INT8U 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 0
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 */
}
#endif
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
*********************************************************************************************************************/
INT8U SD_WaitBusy(INT8U waittype)
{
INT32U timeout, i = 0;
INT8U tmp;
if (waittype == SD_WAIT_WRITE)
timeout = sds.timeout_write; /* 等待類型為寫操作 wait type is write operation */
else
timeout = sds.timeout_erase; /* 等待類型為擦除操作 wait type is erase operation */
#if SD_UCOSII_EN
timeout = SD_UCOSII_SMALLWAIT; /* 很少的等待時間 small wait time */
#endif
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0 always receive 0 when card is busy */
#if SD_UCOSII_EN
if (i >= timeout)
{ /* 很少等待后卡仍忙, after small wait, card is still busy */
if (waittype == SD_WAIT_WRITE)
timeout = sds.timeout_write;
else
timeout = sds.timeout_erase;
i = 0;
do
{
OSTimeDly(1); /* 操作系統掛起1 tick OS suspend 1 tick */
tmp = SPI_RecByte();
i++;
}while ((tmp != 0xFF) && (i < timeout)); /* 忙時收到的值為0 always receive 0 when card is busy */
}
#endif
if(i < timeout)
tmp = SD_NO_ERR; /* 返回0,表示沒超時 return 0 indicate that operation is not time out */
else
tmp = SD_ERR_TIMEOUT_WAIT; /* 返回錯誤碼,表示超時 return error code indicate that operation is time out */
SPI_SendByte(0xFF);
SPI_CS_Deassert();
return tmp; /*返回執行結果 */
}
/********************************************************************************************************************
** 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(INT8U value)
{
INT8U i;
for (i = 0; i < value; i++)
SPI_SendByte(0xFF); /* 發送0xFF clock out 0xFF */
}
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