2012-05-29 04:55 PM
I am new in developing firmware by using STM32L152VBT6. I need to configure DMA to transfer data from SRAM to SD Card. The data would be {1, 2, 3, 4, 5, 6, 7, 8, 9, 0}. However, I could not write into SD Card and I could not find any problem about it.
DMA_InitTypeDef DMA_TestStructure; //Enables the DMA1 peripheral clock. RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); SD_Init(); SD_CS_LOW();DMA_DeInit(DMA1_Channel5);
DMA_TestStructure.DMA_PeripheralBaseAddr = (uint32_t)SD_SPI_DR; DMA_TestStructure.DMA_MemoryBaseAddr = (uint32_t)write_data; DMA_TestStructure.DMA_DIR = DMA_DIR_PeripheralDST; DMA_TestStructure.DMA_BufferSize = 10; DMA_TestStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; DMA_TestStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; DMA_TestStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; DMA_TestStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; DMA_TestStructure.DMA_Mode = DMA_Mode_Normal; DMA_TestStructure.DMA_Priority = DMA_Priority_High; DMA_TestStructure.DMA_M2M = DMA_M2M_Disable; DMA_Init(DMA1_Channel5, &DMA_TestStructure); SPI_I2S_DMACmd(SD_SPI, SPI_I2S_DMAReq_Tx, ENABLE);SD_SendCmd(SD_CMD_WRITE_SINGLE_BLOCK, write_add, 0xFF);
if (!SD_GetResponse(SD_RESPONSE_NO_ERROR)) { /*!< Send a dummy byte */ SD_WriteByte(SD_DUMMY_BYTE); /*!< Send the data token to signify the start of the data */ SD_WriteByte(0xFE); DMA_Cmd(DMA1_Channel5, ENABLE); while (!DMA_GetFlagStatus(DMA1_FLAG_TC5)); SD_ReadByte(); SD_ReadByte(); /* Read data response */ if (SD_GetDataResponse() == SD_DATA_OK) { rvalue = SD_RESPONSE_NO_ERROR; } } SD_CS_HIGH(); SD_WriteByte(SD_DUMMY_BYTE); DMA_Cmd(DMA1_Channel5, DISABLE); #dma-spi-stm32-sd2012-07-16 08:41 PM
The requirement is not allow customer to see the content in the sd card. If use FsFat mean that the customer can straight away open the file.
2012-07-17 07:08 AM
Then you'll want to use SD_ReadBlock, SD_ReadMultiBlocks, SD_WriteBlock and SD_WriteMultiBlocks, to do Sector/Block IO.
If your not up for writing a file system, you could obfuscate the sector content by XOR'ing or encrypting it, at the abstraction layer.2013-01-27 05:49 PM