title: Execution never jumps to DMA IRQHandler in stm32f4105x
body: <p>I'm trying to get a sequence of 1000 samples from ADC1 of STM32f4105VC of STM32f401c-disco, using the DMA transactions. I want the DMA to generate an interrupt when the transfer is complete and to stop there so that no data is overwritten. Here is the code:</p>
  
  <pre><code>/* Private macro -------------------------------------------------------------*/
  #define M 5
  #define F_S 42000000
  #define LOG_SIZE 1000
  #define MEAS_PERIODS 1
  #define DMA_BUFFER_SIZE 1000
  /* Private variables ---------------------------------------------------------*/
  __IO uint16_t uhADCxConvertedValue[DMA_BUFFER_SIZE] = {0};
  __IO uint32_t uwADCxConvertedVoltage = 0;
  double voltage=0;
  double S=0, rms=0, F=0; // S quadratic sums, rms - the rms value, F the frequency
  uint32_t N; //number of samplings
  double unscaled_voltage=0;
  uint32_t max_N=0, steady_N = 0;
  
  typedef char MyString[50];
  MyString Log[LOG_SIZE];
  
  
  
  /* Private function prototypes -----------------------------------------------*/
  /* Private functions ---------------------------------------------------------*/
  static void ADC_Config(void);
  
  
  void DMA2_Stream0_IRQHandler(void) {
      if(DMA_GetITStatus(DMA_STREAMx,DMA_IT_TCIF0)!=RESET) {
     DMA_ClearITPendingBit(DMA_STREAMx,DMA_STREAMx,DMA_IT_TCIF0|DMA_IT_HTIF0);
      }
  }
  
  
  /**
    * @brief  Main program
    * @param  None
    * @retval None
    */
  int main(void)
  {
    /*!&lt; At this stage the microcontroller clock setting is already configured, 
         this is done through SystemInit() function which is called from startup
         files (startup_stm32f40_41xxx.s/startup_stm32f427_437xx.s/startup_stm32f429_439xx.s)
         before to branch to application main. 
         To reconfigure the default setting of SystemInit() function, refer to
         system_stm32f4xx.c file
       */
  
  
  
      double R = 3.0/0xfff; //conversion ratio
      double dc_offset = 1.5;
      double ac_scaling = 0.0022;
      double mv_filter[M]={0};//moving average filter
    uint8_t wave_pos=0; //0 upper half wave, 1 lower half wave
      uint32_t i=0;
      uint8_t i_period = 1;
    /* ADC configuration */
    ADC_Config();
  
    /* Start ADC Software Conversion */ 
  //   ADC_SoftwareStartConv(ADCx);
      ADC_SoftwareStartConv(ADCx);
    while (1) {}
  }
  
  static void ADC_Config(void)
  {
    ADC_InitTypeDef       ADC_InitStructure;
    ADC_CommonInitTypeDef ADC_CommonInitStructure;
    DMA_InitTypeDef       DMA_InitStructure;
    GPIO_InitTypeDef      GPIO_InitStructure;
      NVIC_InitTypeDef            NVIC_InitStructure;
  
    /* Enable ADCx, DMA and GPIO clocks ****************************************/ 
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
    RCC_AHB1PeriphClockCmd(ADCx_CHANNEL_GPIO_CLK, ENABLE);  
    RCC_APB2PeriphClockCmd(ADCx_CLK, ENABLE);
  
      /* Enable the DMA2 Stream0 Global Interrupt (to handle the Transfer Complete Interrupt TCIF) */
      NVIC_InitStructure.NVIC_IRQChannel = DMA2_Stream0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&amp;NVIC_InitStructure);
  
    /* DMA2 Stream0 channel15 configuration **************************************/
    DMA_InitStructure.DMA_Channel = DMA_CHANNELx;  
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADCx_DR_ADDRESS;
    DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&amp;uhADCxConvertedValue[0];
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
    DMA_InitStructure.DMA_BufferSize = DMA_BUFFER_SIZE;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;         
    DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
    DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
    DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
    DMA_Init(DMA_STREAMx, &amp;DMA_InitStructure);
    DMA_Cmd(DMA_STREAMx, ENABLE);
  
    /* Configure ADC1 Channel15 pin as analog input ******************************/
    GPIO_InitStructure.GPIO_Pin = GPIO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
    GPIO_Init(GPIO_PORT, &amp;GPIO_InitStructure);
  
    /* ADC Common Init **********************************************************/
    ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
    ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
    ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1;
    ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
    ADC_CommonInit(&amp;ADC_CommonInitStructure);
  
    /* ADC1 Init ****************************************************************/
    ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
    ADC_InitStructure.ADC_ScanConvMode = DISABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
    ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfConversion = 1;
    ADC_Init(ADCx, &amp;ADC_InitStructure);
  
    /* ADC1 regular channel15 configuration **************************************/
    ADC_RegularChannelConfig(ADCx, ADC_CHANNEL, 1, ADC_SampleTime_3Cycles);
  
  //  /* Enable DMA request after last transfer (Single-ADC mode) */
    ADC_DMARequestAfterLastTransferCmd(ADCx, ENABLE);
  
  //   /* Enable ADC1 DMA */
    ADC_DMACmd(ADCx, ENABLE);
  
    /* Enable ADC1 */
    ADC_Cmd(ADCx, ENABLE);
  
      DMA_ITConfig(DMA_STREAMx,DMA_IT_TC,ENABLE);
  }
  </code></pre>
  
  <p>When I debug the program after some time the DMA stops and the flags <code>TCIF0</code> and <code>HTIF0</code> are set in the the register <code>DMA_LISR</code>, though a breakpoint in the <code>DMA2_Stream0_IRQHandler</code> function is only once activated. Why?</p>