SPI2发送使用DMA操作的数据不对

helh 2009-5-21 17:20 楼主

我使用SPI2操作M25P64,在写M25P64的时候，如果使用软件发送，读回来的数据是正确的，但是如果使用DMA发送数据即不正确。读回来的数据是0xff.下面是写M25P64的代码，帮忙看看是什么问题？是不是发送用DMA时没有对时钟进行控制，造成对SPI2写溢出？
static void DMA_TxConfiguration(const INT8U *BufferSRC, INT32U BufferSize)
{
    DMA_InitTypeDef DMA_InitStructure;

    DMA_ClearFlag(DMA1_FLAG_TC5 | DMA1_FLAG_TE5 | DMA1_FLAG_HT5 | DMA1_FLAG_GL5);

    /* DMA1 Channel5 disable */
    DMA_Cmd(DMA1_Channel5, DISABLE);

    /* DMA1 Channel5 Config */
    DMA_InitStructure.DMA_PeripheralBaseAddr = (INT32U)SPI2_DR_Address;
    DMA_InitStructure.DMA_MemoryBaseAddr = (INT32U)BufferSRC;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = BufferSize;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel5, &DMA_InitStructure);

    /* Enable SPI2 DMA Tx request */
    SPI_I2S_DMACmd(SPI2, SPI_I2S_DMAReq_Tx, ENABLE);
    /* DMA1 Channel3 enable */
    DMA_Cmd(DMA1_Channel5, ENABLE);
    while(!DMA_GetFlagStatus(DMA1_FLAG_TC5));
}
static void SPI_FLASH_PageWrite(const INT8U* pBuffer,INT32U WriteAddr,INT16U NumByteToWrite)
{
    if(0 == NumByteToWrite)
        return;
    /* Enable the write access to the FLASH */
    SPI_FLASH_WriteEnable();

    /* Select the FLASH: Chip Select low */
    SPI_FLASH_CS_LOW();
    /* Send "Write to Memory " instruction */
    SPI_FLASH_SendByte(WRITE);
    /* Send WriteAddr high nibble address byte to write to */
    SPI_FLASH_SendByte((WriteAddr & 0xFF0000) >> 16);
    /* Send WriteAddr medium nibble address byte to write to */
    SPI_FLASH_SendByte((WriteAddr & 0xFF00) >> 8);
    /* Send WriteAddr low nibble address byte to write to */
    SPI_FLASH_SendByte(WriteAddr & 0xFF);
#if 1
    /* while there is data to be written on the FLASH */
    while(NumByteToWrite--)
    {
        /* Send the current byte */
        SPI_FLASH_SendByte(*pBuffer);
        /* Point on the next byte to be written */
        pBuffer++;
    }
    /* Deselect the FLASH: Chip Select high */
    SPI_FLASH_CS_HIGH();
    /* Wait the end of Flash writing */
    SPI_FLASH_WaitForWriteEnd();
#else
    DMA_TxConfiguration(pBuffer,NumByteToWrite);
    SPI_FLASH_CS_HIGH();
    SPI_FLASH_WaitForWriteEnd();
#endif
}