请原子哥帮我看看，STM32 SPI FLASH使用DMA，仅仅初始化DMA和使能DMA有用吗？

墨染卿卿 · 发表于 2014-10-31 14:44:30

1、程序如下，我初始化了DMA，在main函数里我不确定要不要加SPI_FLASH_BufferWrite(Tx_Buffer, FLASH_WriteAddress, BufferSize);不加没显示，加了我不确定DMA工作没。

我试过，把赋值给SPI_DR的程序换成SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Rx, ENABLE); 这样也不对。请原子哥指点一下。

2、再比如I2C要用DMA，应该在写了从器件地址后面用使能dma，但是具体在哪里用，我也不清楚。请原子哥指点一下。

int main(void)
{
        /* 配置串口1为：115200 8-N-1 */
        USART1_Config();
        SPI_DMA_Config();


        /* 2M串行flash W25Q16初始化 */
        SPI_FLASH_Init();

                /* Erase SPI FLASH Sector to write on */
                SPI_FLASH_SectorErase(FLASH_SectorToErase);

                /* 将发送缓冲区的数据写到flash中 */
                SPI_FLASH_BufferWrite(Tx_Buffer, FLASH_WriteAddress, BufferSize);
                SPI_I2S_DMACmd(SPI1,SPI_I2S_DMAReq_Tx,ENABLE);
                printf("\r\n 写入的数据为：%s \r\t", Tx_Buffer);

                /* 将刚刚写入的数据读出来放到接收缓冲区中 */

                SPI_FLASH_BufferRead(Rx_Buffer, FLASH_ReadAddress, BufferSize);
                  SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Rx, ENABLE);
                printf("\r\n 读出的数据为：%s \r\n", Rx_Buffer);

}
void SPI_DMA_Config(){
        DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
        DMA_DeInit(DMA1_Channel2);//RX
        DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)0x4001300c;
        DMA_InitStructure.DMA_MemoryBaseAddr = (u32)Rx_Buffer; // from function input parameter
        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; // fixed for send function
        DMA_InitStructure.DMA_BufferSize = BufferSize; // from function input parameter
        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; // fixed
        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; // fixed
        DMA_InitStructure.DMA_PeripheralDataSize = DMA_MemoryDataSize_Byte; //fixed
        DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; //fixed
        DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; // fixed
        DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh; // up to user
        DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; // fixed

        DMA_Init(DMA1_Channel2, &DMA_InitStructure);
        SPI1->CR2|= 1<<0;//接受缓冲区使能
        DMA_Cmd(DMA1_Channel2,ENABLE);

        DMA_DeInit(DMA1_Channel3);//TX
        DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)0x4001300c;
        DMA_InitStructure.DMA_MemoryBaseAddr = (u32)Tx_Buffer; // from function input parameter
        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST; // fixed for send function
        DMA_InitStructure.DMA_BufferSize = BufferSize; // from function input parameter
        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; // fixed
        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; // fixed
        DMA_InitStructure.DMA_PeripheralDataSize = DMA_MemoryDataSize_Byte; //fixed
        DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; //fixed
        DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; // fixed
        DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh; // up to user
        DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; // fixed

        DMA_Init(DMA1_Channel3, &DMA_InitStructure);
        //DMA_ITConfig(DMA1_Channel3, DMA_IT_TC, ENABLE);
        SPI1->CR2|= 1<<1;//接受缓冲区使能
        DMA_Cmd(DMA1_Channel3,ENABLE);
}