本帖最后由 z32437089 于 2014-10-31 15:38 编辑
使用SPI2驱动SD卡，发送CMD0命令，SD卡没任何反应，就一直卡到这里了，换V1和V2的卡都没反应，MISO引脚永远是低电平.
这个是SD卡硬件连接图
SD硬件
CDMO对应MCU_MOSI第28个腿PB15，CDMI对应MCU_MISO第27个腿PB14
- void SD_SendCmd ( /* Return value: R1 resp (bit7==1:Failed to send) */
- BYTE cmd, /* Command index */
- DWORD arg, /* Argument */
- BYTE crc
- )
- {
- // BYTE n, res;
- /* Send command packet */
- xchg_spi(0x40 | cmd); /* Start + command index */
- xchg_spi((BYTE)(arg >> 24)); /* Argument[31..24] */
- xchg_spi((BYTE)(arg >> 16)); /* Argument[23..16] */
- xchg_spi((BYTE)(arg >> 8)); /* Argument[15..8] */
- xchg_spi((BYTE)arg); /* Argument[7..0] */
- xchg_spi(crc);}
- SD_Error SD_GetResponse(uint8_t Response)
- {
- uint32_t Count = 0xFFF;
- /*!< Check if response is got or a timeout is happen */
- while ((xchg_spi(0xFF) != Response) && Count)
- {
- Count--;
- }
- if (Count == 0)
- {
- /*!< After time out */
- return SD_RESPONSE_FAILURE;
- }
- else
- {
- /*!< Right response got */
- return SD_RESPONSE_NO_ERROR;
- }
- }
- SD_Error SD_Init (void)
- {
- uint32_t i = 0;
- GPIO_InitTypeDef GPIO_InitStructure;
- SPI_InitTypeDef SPI_InitStructure;
- RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB,ENABLE);
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2,ENABLE);
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15 ;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_3;
- GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
- GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_0); //SCK
- GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_0); //MI
- GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_0); //MO
- /* SPI CS PIN Configuration --------------------------------------------------*/
- /* Configure I/O for Flash Chip select */
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
- /* SPI configuration */
- SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
- SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
- SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
- SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
- SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
- SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
- SPI_InitStructure.SPI_BaudRatePrescaler = SPIx_SD_BAUDRATE_SLOW; // 48000kHz/128=375kHz < 400kHz
- SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
- SPI_InitStructure.SPI_CRCPolynomial = 7;
- SPI_Init(SPI2, &SPI_InitStructure);
- SPI_RxFIFOThresholdConfig(SPI2, SPI_RxFIFOThreshold_QF);
- SPI_CalculateCRC(SPI2, DISABLE);
- SPI_Cmd(SPI2, ENABLE); /* Enable SPI function */
- CS_HIGH(); /* Set CS# high */
- /*!< Send dummy byte 0xFF, 10 times with CS high */
- /*!< Rise CS and MOSI for 80 clocks cycles */
- for (i = 0; i < 10; i++)
- {
- xchg_spi(0xff);
- }
- /*-------Put SD in SPI mode----- 设置SD为SPI模式 -----*/
- /*!< SD initialized and set to SPI mode properly */
- return (SD_GoIdleState());
- }
- SD_Error SD_GoIdleState(void)
- {
- /*!< SD chip select low */
- CS_LOW();
- /*!< Send CMD0 (SD_CMD_GO_IDLE_STATE) to put SD in SPI mode */
- do {SD_SendCmd(SD_CMD_GO_IDLE_STATE, 0, 0x95);}
- while(SD_GetResponse(SD_IN_IDLE_STATE));
- led1_on;while(1);//can't reach here,led1 remains off
- /*----------Activates the card initialization process-----------*/
- do
- {
- /*!< SD chip select high */
- CS_HIGH();
- /*!< Send Dummy byte 0xFF */
- xchg_spi(0xff);
- /*!< SD chip select low */
- CS_LOW();
- /*!< Send CMD1 (Activates the card process) until response equal to 0x0 */
- SD_SendCmd(SD_CMD_SEND_OP_COND, 0, 0xFF);
- /*!< Wait for no error Response (R1 Format) equal to 0x00 */
- }
- while (SD_GetResponse(SD_RESPONSE_NO_ERROR));
- /*!< SD chip select high */
- CS_HIGH();
- /*!< Send dummy byte 0xFF */
- xchg_spi(0xff);
- return SD_RESPONSE_NO_ERROR;
- }
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