/*
* 函数名：SD_PowerON
* 描述 ：确保SD卡的工作电压和配置控制时钟
* 输入 ：无
* 输出 ：-SD_Error SD卡错误代码
* 成功时则为 SD_OK
* 调用 ：在 SD_Init() 调用
*/
SD_Error SD_PowerON(void)
{
SD_Error errorstatus = SD_OK;
uint32_t response = 0, count = 0, validvoltage = 0;
uint32_t SDType = SD_STD_CAPACITY;
/*!< Power ON Sequence -----------------------------------------------------*/
/*!< Configure the SDIO peripheral */
/*!< SDIOCLK = HCLK, SDIO_CK = HCLK/(2 + SDIO_INIT_CLK_DIV) */
/*!< on STM32F2xx devices, SDIOCLK is fixed to 48MHz */
/*!< SDIO_CK for initialization should not exceed 400 KHz */
/*初始化时的时钟不能大于400KHz*/
SDIO_InitStructure.SDIO_ClockDiv = SDIO_INIT_CLK_DIV; /* HCLK = 72MHz, SDIOCLK = 72MHz, SDIO_CK = HCLK/(178 + 2) = 400 KHz */
SDIO_InitStructure.SDIO_ClockEdge = SDIO_ClockEdge_Rising;
SDIO_InitStructure.SDIO_ClockBypass = SDIO_ClockBypass_Disable; //不使用bypass模式，直接用HCLK进行分频得到SDIO_CK
SDIO_InitStructure.SDIO_ClockPowerSave = SDIO_ClockPowerSave_Disable; // 空闲时不关闭时钟电源
SDIO_InitStructure.SDIO_BusWide = SDIO_BusWide_1b; //1位数据线
SDIO_InitStructure.SDIO_HardwareFlowControl = SDIO_HardwareFlowControl_Disable;//硬件流
SDIO_Init(&SDIO_InitStructure);
/*!< Set Power State to ON */
SDIO_SetPowerState(SDIO_PowerState_ON);
/*!< Enable SDIO Clock */
SDIO_ClockCmd(ENABLE);
/*下面发送一系列命令,开始卡识别流程*/
/*!< CMD0: GO_IDLE_STATE ---------------------------------------------------*/
/*!< No CMD response required */
SDIO_CmdInitStructure.SDIO_Argument = 0x0;
SDIO_CmdInitStructure.SDIO_CmdIndex = SD_CMD_GO_IDLE_STATE; //cmd0
SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_No; //无响应
SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No;
SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable; //则CPSM在开始发送命令之前等待数据传输结束。
SDIO_SendCommand(&SDIO_CmdInitStructure); //写命令进命令寄存器
errorstatus = CmdError();//检测是否正确接收到cmd0
if (errorstatus != SD_OK) //命令发送出错，返回
{
/*!< CMD Response TimeOut (wait for CMDSENT flag) */
return(errorstatus);
}
/*!< CMD8: SEND_IF_COND ----------------------------------------------------*/
/*!< Send CMD8 to verify SD card interface operating condition */
/*!< Argument: - [31:12]: Reserved (shall be set to '0')
- [11:8]: Supply Voltage (VHS) 0x1 (Range: 2.7-3.6 V)
- [7:0]: Check Pattern (recommended 0xAA) */
/*!< CMD Response: R7 */
SDIO_CmdInitStructure.SDIO_Argument = SD_CHECK_PATTERN; //接收到命令sd会返回这个参数
SDIO_CmdInitStructure.SDIO_CmdIndex = SDIO_SEND_IF_COND; //cmd8
SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_Short; //r7
SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No; //关闭等待中断
SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable;
SDIO_SendCommand(&SDIO_CmdInitStructure);
/*检查是否接收到命令*/
errorstatus = CmdResp7Error();
if (errorstatus == SD_OK) //有响应则card遵循sd协议2.0版本
{
CardType = SDIO_STD_CAPACITY_SD_CARD_V2_0; /*!< SD Card 2.0 ，先把它定义会sdsc类型的卡*/
SDType = SD_HIGH_CAPACITY; //这个变量用作acmd41的参数，用来询问是sdsc卡还是sdhc卡
}
else //无响应，说明是1.x的或mmc的卡
{
/*!< CMD55 */
SDIO_CmdInitStructure.SDIO_Argument = 0x00;
SDIO_CmdInitStructure.SDIO_CmdIndex = SD_CMD_APP_CMD;
SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_Short;
SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No;
SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable;
SDIO_SendCommand(&SDIO_CmdInitStructure);
errorstatus = CmdResp1Error(SD_CMD_APP_CMD);
}
/*!< CMD55 */ //为什么在else里和else外面都要发送CMD55?
//发送cmd55，用于检测是sd卡还是mmc卡，或是不支持的卡
SDIO_CmdInitStructure.SDIO_Argument = 0x00;
SDIO_CmdInitStructure.SDIO_CmdIndex = SD_CMD_APP_CMD;
SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_Short; //r1
SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No;
SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable;
SDIO_SendCommand(&SDIO_CmdInitStructure);
errorstatus = CmdResp1Error(SD_CMD_APP_CMD); //是否响应，没响应的是mmc或不支持的卡
/*!< If errorstatus is Command TimeOut, it is a MMC card */
/*!< If errorstatus is SD_OK it is a SD card: SD card 2.0 (voltage range mismatch)
or SD card 1.x */
if (errorstatus == SD_OK) //响应了cmd55，是sd卡，可能为1.x,可能为2.0
{
/*下面开始循环地发送sdio支持的电压范围，循环一定次数*/
/*!< SD CARD */
/*!< Send ACMD41 SD_APP_OP_COND with Argument 0x80100000 */
while ((!validvoltage) && (count < SD_MAX_VOLT_TRIAL))
{
//因为下面要用到ACMD41，是ACMD命令，在发送ACMD命令前都要先向卡发送CMD55
/*!< SEND CMD55 APP_CMD with RCA as 0 */
SDIO_CmdInitStructure.SDIO_Argument = 0x00;
SDIO_CmdInitStructure.SDIO_CmdIndex = SD_CMD_APP_CMD; //CMD55
SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_Short;
SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No;
SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable;
SDIO_SendCommand(&SDIO_CmdInitStructure);
errorstatus = CmdResp1Error(SD_CMD_APP_CMD); //检测响应
if (errorstatus != SD_OK)
{
return(errorstatus);//没响应CMD55，返回
}
//acmd41，命令参数由支持的电压范围及HCS位组成，HCS位置一来区分卡是SDSc还是sdhc
SDIO_CmdInitStructure.SDIO_Argument = SD_VOLTAGE_WINDOW_SD | SDType; //参数为主机可供电压范围及hcs位
SDIO_CmdInitStructure.SDIO_CmdIndex = SD_CMD_SD_APP_OP_COND;
SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_Short; //r3
SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No;
SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable;
SDIO_SendCommand(&SDIO_CmdInitStructure);
errorstatus = CmdResp3Error(); //检测是否正确接收到数据
if (errorstatus != SD_OK)
{
return(errorstatus); //没正确接收到acmd41，出错，返回
}
/*若卡需求电压在SDIO的供电电压范围内，会自动上电并标志pwr_up位*/
response = SDIO_GetResponse(SDIO_RESP1); //读取卡寄存器，卡状态
validvoltage = (((response >> 31) == 1) ? 1 : 0); //读取卡的ocr寄存器的pwr_up位，看是否已工作在正常电压
count++; //计算循环次数
}
if (count >= SD_MAX_VOLT_TRIAL) //循环检测超过一定次数还没上电
{
errorstatus = SD_INVALID_VOLTRANGE; //SDIO不支持card的供电电压
return(errorstatus);
}
/*检查卡返回信息中的HCS位*/
if (response &= SD_HIGH_CAPACITY) //判断ocr中的ccs位 ，如果是sdsc卡则不执行下面的语句
{
CardType = SDIO_HIGH_CAPACITY_SD_CARD; //把卡类型从初始化的sdsc型改为sdhc型
}
}/*!< else MMC Card */
return(errorstatus);
}
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