定时器触发DMA问题

zerone

void TIM2_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
    DMA_InitTypeDef DMA_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;
  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  TIM_OCInitTypeDef  TIM_OCInitStructure;

  uint32_t uhTimerPeriod = 0;
  uint16_t i;
  
  TIM2_PWM_frequency = 10;     // 10kHz

  uhTimerPeriod = ((SystemCoreClock /2) / TIM2_PWM_frequency) - 1;
  SRC_Buffer[0] = uhTimerPeriod / 2;
  
  for(i = 1; i < 1024; i++){
    SRC_Buffer = SRC_Buffer[0];
  }  
  
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
    
    /* Connect TIM2 pins to AF */  
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource15, GPIO_AF_TIM2);
    
  /* GPIOC Configuration: TIM2 CH1 (PA15) */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
  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_DOWN;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

    //
    DMA_Cmd(DMA1_Stream5, DISABLE);
    DMA_DeInit(DMA1_Stream5);    
    while (DMA_GetCmdStatus(DMA1_Stream5) != DISABLE){;}
            
  DMA_InitStructure.DMA_Channel = DMA_Channel_3;  
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&TIM2->CCR1);
    DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)SRC_Buffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
    DMA_InitStructure.DMA_BufferSize = 100;    //DMA1_TIM2_Pulse;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
    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(DMA1_Stream5, &DMA_InitStructure);

  NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream5_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 7;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period = uhTimerPeriod;
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

  /* PWM1 Mode configuration: Channel1 */
    TIM_OCStructInit(&TIM_OCInitStructure);
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = uhTimerPeriod / 2;//SRC_Buffer[0];
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OC1Init(TIM2, &TIM_OCInitStructure);

    /* TIM2 Update DMA Request enable */
    TIM_DMACmd(TIM2, TIM_DMA_CC1, ENABLE);     //这句可以
      //TIM_DMACmd(TIM2, TIM_DMA_Update, ENABLE);      //用这句就触发不了DMA，不知道什么原因


  /* STM32F407 TIM2_UP DMA1_Stream5 Channel 3 */
    DMA_ClearFlag(DMA1_Stream5, DMA_IT_TCIF5);
    DMA_ITConfig(DMA1_Stream5, DMA_IT_TC, ENABLE);
    DMA_Cmd(DMA1_Stream5, ENABLE);
        
    TIM_Cmd(TIM2, ENABLE);
}

eric2013

必须用CC，在参数手册上面讲解触发方式时有说。