STM32F070使用ll库 - usart-dma-空闲中断

void MX_USART1_UART_Init(void)
{
    /* USER CODE BEGIN USART1_Init 0 */
    /* USER CODE END USART1_Init 0 */
    LL_USART_InitTypeDef USART_InitStruct = {0};
    LL_GPIO_InitTypeDef GPIO_InitStruct = {0};
    /* Peripheral clock enable */
    LL_APB1_GRP2_EnableClock(LL_APB1_GRP2_PERIPH_USART1);
    LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOA);
    /**USART1 GPIO Configuration
    PA9   ------> USART1_TX
    PA10   ------> USART1_RX
    */
    GPIO_InitStruct.Pin = LL_GPIO_PIN_9;
    GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
    GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
    GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
    GPIO_InitStruct.Alternate = LL_GPIO_AF_1;
    LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = LL_GPIO_PIN_10;
    GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
    GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
    GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
    GPIO_InitStruct.Alternate = LL_GPIO_AF_1;
    LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* USART1 DMA Init */
    /* USART1_RX Init */
    LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_CHANNEL_3, LL_DMA_DIRECTION_PERIPH_TO_MEMORY);
    LL_DMA_SetChannelPriorityLevel(DMA1, LL_DMA_CHANNEL_3, LL_DMA_PRIORITY_LOW);
    LL_DMA_SetMode(DMA1, LL_DMA_CHANNEL_3, LL_DMA_MODE_NORMAL);
    LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_CHANNEL_3, LL_DMA_PERIPH_NOINCREMENT);
    LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_CHANNEL_3, LL_DMA_MEMORY_INCREMENT);
    LL_DMA_SetPeriphSize(DMA1, LL_DMA_CHANNEL_3, LL_DMA_PDATAALIGN_BYTE);
    LL_DMA_SetMemorySize(DMA1, LL_DMA_CHANNEL_3, LL_DMA_MDATAALIGN_BYTE);
    /* USART1 interrupt Init */
    /* USER CODE BEGIN USART1_Init 1 */
    /* USER CODE END USART1_Init 1 */
    USART_InitStruct.BaudRate = 115200;
    USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B;
    USART_InitStruct.StopBits = LL_USART_STOPBITS_1;
    USART_InitStruct.Parity = LL_USART_PARITY_NONE;
    USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX;
    USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE;
    USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16;
    LL_USART_Init(USART1, &USART_InitStruct);
    LL_USART_DisableIT_CTS(USART1);
    LL_USART_ConfigAsyncMode(USART1);
    LL_USART_Enable(USART1);
    /* USER CODE BEGIN USART1_Init 2 */
    LL_DMA_SetMemoryAddress(DMA1, LL_DMA_CHANNEL_3, (uint32_t)Usart1RxBuf);
    LL_DMA_SetPeriphAddress(DMA1, LL_DMA_CHANNEL_3, (uint32_t)&USART1->RDR);
    LL_DMA_SetDataLength(DMA1, LL_DMA_CHANNEL_3, USART1_RXBUFF_SIZE);

    LL_USART_ClearFlag_TC(USART1);
    LL_USART_EnableIT_IDLE(USART1);
    NVIC_SetPriority(USART1_IRQn, 0);
    NVIC_EnableIRQ(USART1_IRQn);

    LL_DMA_ClearFlag_TC3(DMA1);
    LL_DMA_EnableIT_TC(DMA1, LL_DMA_CHANNEL_3);
    LL_DMA_EnableChannel(DMA1, LL_DMA_CHANNEL_3);
    NVIC_SetPriority(DMA1_Channel2_3_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(), 0, 0));
    NVIC_EnableIRQ(DMA1_Channel2_3_IRQn);

    LL_USART_EnableDMAReq_RX(USART1);
}

void USART1_IRQHandler(void)
{
    uint8_t len;
    if(LL_USART_IsActiveFlag_IDLE(USART1) && LL_USART_IsEnabledIT_IDLE(USART1)) //检测是否接收中断
    {
        USART1->ISR;            // 清除IDLE标志位
        USART1->RDR;
        LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_3);
        LL_DMA_ClearFlag_TC3(DMA1);
        LL_USART_ClearFlag_IDLE(USART1);

        len = USART1_RXBUFF_SIZE - LL_DMA_GetDataLength(DMA1, LL_DMA_CHANNEL_3);
        if(len > 0)
        {
            ProcessData(Usart1RxBuf, len);
        }

        LL_DMA_SetMemoryAddress(DMA1, LL_DMA_CHANNEL_3, (uint32_t)Usart1RxBuf);
        LL_DMA_SetPeriphAddress(DMA1, LL_DMA_CHANNEL_3, (uint32_t)&USART1->RDR);
        LL_DMA_SetDataLength(DMA1, LL_DMA_CHANNEL_3, USART1_RXBUFF_SIZE);
        LL_DMA_EnableChannel(DMA1, LL_DMA_CHANNEL_3);
    }
}