STM32F4 USART DMA - Kein Restart

char txbuffer[10] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};

void USART3_INIT()

{

  /* Enable GPIO clock for UM6 USART*/

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

  /* Enable USART clock */

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);

  // Init GPIOs

  GPIO_InitTypeDef   GPIO_InitStructure;

  // Configure USART

  GPIO_InitStructure.GPIO_Pin               = GPIO_Pin_10 | GPIO_Pin_11;

  GPIO_InitStructure.GPIO_Mode               = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_Speed               = GPIO_Speed_100MHz;

  GPIO_InitStructure.GPIO_OType               = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd               = GPIO_PuPd_UP;

  GPIO_Init(GPIOB, &GPIO_InitStructure);

  /* UM6 USART GPIO configuration -----------------------------------------------*/

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_USART3);

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_USART3);

  // Configure UM6 USART

  USART_InitTypeDef   USART_InitStructure;

  USART_InitStructure.USART_BaudRate             = 115200;

  USART_InitStructure.USART_WordLength           = USART_WordLength_8b;

  USART_InitStructure.USART_StopBits             = USART_StopBits_1;

  USART_InitStructure.USART_Parity             = USART_Parity_No;

  USART_InitStructure.USART_HardwareFlowControl       = USART_HardwareFlowControl_None;

  USART_InitStructure.USART_Mode               = USART_Mode_Rx | USART_Mode_Tx;

  USART_Init(USART3, &USART_InitStructure);

  // Enable receive interrupt on USART3

  USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);

  // Setup NVIC

  NVIC_InitTypeDef   NVIC_InitStructure;

  NVIC_InitStructure.NVIC_IRQChannel             = USART3_IRQn;

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority  = 0;

  NVIC_InitStructure.NVIC_IRQChannelSubPriority      = 0;

  NVIC_InitStructure.NVIC_IRQChannelCmd          = ENABLE;

  NVIC_Init(&NVIC_InitStructure);

  /* Enable USART */

  USART_Cmd(USART3, ENABLE);

  // Enable DMA TX for USART

  /* Enable the DMA clock */

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);

  // Configure USART TX DMA

  DMA_InitTypeDef    dma_is;

  DMA_StructInit(&dma_is);                                  // Init dma structure (clear structure)

  dma_is.DMA_Channel                    = DMA_Channel_4;          // Select DMA channel (see reference manual, DMA1 request mapping)

  dma_is.DMA_Mode                      = DMA_Mode_Normal;          // Normal mode, not circular!

  dma_is.DMA_FIFOMode                    = DMA_FIFOMode_Disable;        // Disable FIFO mode

  //dma_is.DMA_FIFOThreshold                = DMA_FIFOThreshold_1QuarterFull;  // Irrelevant as direct mode is used (FIFO disabled)

  dma_is.DMA_DIR                      = DMA_DIR_MemoryToPeripheral;    // DMA direction definition (memory to peripheral)

  dma_is.DMA_Priority                    = DMA_Priority_Medium;        // Set priority

  dma_is.DMA_BufferSize                  = 10;                // Buffer size

  dma_is.DMA_Memory0BaseAddr                = (uint32_t)&txbuffer;        // Base address of buffer

  dma_is.DMA_MemoryInc                  = DMA_MemoryInc_Enable;        // Increment memory address enabled

  dma_is.DMA_MemoryBurst                  = DMA_MemoryBurst_Single;      // Set burst mode to single

  dma_is.DMA_MemoryDataSize                = DMA_MemoryDataSize_Byte;      // Set memory data size to BYTE

  dma_is.DMA_PeripheralBaseAddr              = (uint32_t)&(USART3->DR);      // Select peripheral base address (USART data register)

  dma_is.DMA_PeripheralInc                = DMA_PeripheralInc_Disable;    // Increment peripheral address disabled

  dma_is.DMA_PeripheralBurst                = DMA_PeripheralBurst_Single;    // Set peripheral burst mode to single

  dma_is.DMA_PeripheralDataSize              = DMA_PeripheralDataSize_Byte;    // Set peripheral data size to BYTE

  DMA_Init(DMA1_Stream3, &dma_is);                              // Init DMA

  USART_DMACmd(USART3, USART_DMAReq_Tx, ENABLE);                        // Enable USART DMA TX Requsts

  // Enable TX DMA transfer complete interrupt

  //DMA_ITConfig(USARTy_TX_DMA_STREAM, DMA_IT_TC, ENABLE);

}

int main(void)

{

  // Locals

  // ----------------------------------------------------------------------------------------------------------

  // Board initialization

  // ----------------------------------------------------------------------------------------------------------

  // Init LEDs

  LED_INIT();

  // Init serial port

  USART_INIT();

  // ----------------------------------------------------------------------------------------------------------

  // ----------------------------------------------------------------------------------------------------------

  // PRODUCTIVE LOOP

  // ----------------------------------------------------------------------------------------------------------

  // ----------------------------------------------------------------------------------------------------------

  int i = 0;

  int led = 0;

    while(1)

    {

      Delay(500000);

      LED1_ON;

      Delay(500000);

      LED1_OFF;

      if (i++ > 5)

      {

        StartDMA();

        i = 0;

      }

    }

}

/***************************************************************************************************************/

void Delay(__IO uint32_t nCount)

{

  while(nCount--)

  {

  }

}