N32G4FR芯片DAC的DMA开不起来，请帮忙看看

//DAC DMA IRQ

void DMA2_Channel3_IRQHandler(void)

{

        //DAC DMA full transfer IRQ

//这个中断始终进不来        

....

}



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

void dac_gpio_config(void)

{

        GPIO_InitType gpio_init_struct;



        // PA4 = DAC1

        gpio_init_struct.GPIO_Mode  = GPIO_Mode_AIN;

        gpio_init_struct.Pin        = GPIO_PIN_4;

        GPIO_InitPeripheral(GPIOA, &gpio_init_struct);

}



static void nvic_config(IRQn_Type irq)

{

    NVIC_InitType NVIC_InitStructure;



    /* Enable the Interrupt */

    NVIC_InitStructure.NVIC_IRQChannel                   = irq;

    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

    NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 0;

    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;

    NVIC_Init(&NVIC_InitStructure);

}



void dac_dma_config(void)

{

    DMA_InitType DMA_InitStructure;



    DMA_DeInit(DMA2_CH3);

    DMA_InitStructure.PeriphAddr     = (uint32_t)DAC->DR12CH1;

    DMA_InitStructure.MemAddr        = (uint32_t)dac_Wave;

    DMA_InitStructure.Direction      = DMA_DIR_PERIPH_DST;

    DMA_InitStructure.BufSize        = TUNE_LEN_DAC;

    DMA_InitStructure.PeriphInc      = DMA_PERIPH_INC_DISABLE;

    DMA_InitStructure.DMA_MemoryInc  = DMA_MEM_INC_ENABLE;

    DMA_InitStructure.PeriphDataSize = DMA_PERIPH_DATA_SIZE_HALFWORD;

    DMA_InitStructure.MemDataSize    = DMA_MemoryDataSize_HalfWord;

    DMA_InitStructure.CircularMode   = DMA_MODE_CIRCULAR;

    DMA_InitStructure.Priority       = DMA_PRIORITY_HIGH;

    DMA_InitStructure.Mem2Mem        = DMA_M2M_DISABLE;

    DMA_Init(DMA2_CH3, &DMA_InitStructure);



    DMA_EnableChannel(DMA2_CH3, ENABLE);



        DMA_ConfigInt(DMA2_CH3, DMA_INT_TXC | DMA_INT_HTX, ENABLE);



        /* dma1 channel1 interrupt nvic init */

        nvic_config(DMA2_Channel3_IRQn);

}



void TIM2_TrgoInit(void)

{

    TIM_TimeBaseInitType TIM_TimeBaseStructure;



    /* TIM2 Configuration */

    /* Time base configuration */

    TIM_InitTimBaseStruct(&TIM_TimeBaseStructure);

    TIM_TimeBaseStructure.Period    = 108-1;//108MHz/108=1MHz

    TIM_TimeBaseStructure.Prescaler = 0x0;

    TIM_TimeBaseStructure.ClkDiv    = 0x0;

    TIM_TimeBaseStructure.CntMode   = TIM_CNT_MODE_UP;

    TIM_InitTimeBase(TIM2, &TIM_TimeBaseStructure);



    /* TIM2 TRGO selection */

    TIM_SelectOutputTrig(TIM2, TIM_TRGO_SRC_UPDATE);

}



void dac_config(void)

{

        DAC_InitType dac_init_struct;



        TIM2_TrgoInit();

        

        /* dac1 configuration */

        DAC_ClearStruct(&dac_init_struct);

    dac_init_struct.Trigger      = DAC_TRG_T2_TRGO;

    dac_init_struct.WaveGen      = DAC_WAVEGEN_NONE;

    dac_init_struct.BufferOutput = DAC_BUFFOUTPUT_DISABLE;

    DAC_Init(DAC_CHANNEL_1, &dac_init_struct);



        dac_dma_config();



        DAC_Enable(DAC_CHANNEL_1, ENABLE);

}



void dac_setup(void)

{

        dac_gpio_config();

        dac_config();

}



void dac_start(void)

{

        DAC_DmaEnable(DAC_CHANNEL_1, ENABLE); // DAC



        /* enable tmr2 */

        TIM_Enable(TIM2, ENABLE);

}