STM32 USART DMA方式配置 - - Powered by Discuz!

#define USART1_BUFF_SIZE 1024
uint8_t usart1_tx_buffer[USART1_BUFF_SIZE]; /* 串口发送缓存 */
uint8_t usart1_rx_buffer[USART1_BUFF_SIZE]; /* 串口接受缓存 */
uint16_t usart1_tx_flag = 0; /* 接收一帧数据标志，并记录接收数据个数 */
/********************************************************************************************************
** 函数: USART1_Init, 串口1初始化
**------------------------------------------------------------------------------------------------------
** 参数：bound 波特兰
** 返回: 无
********************************************************************************************************/
void USART1_Init(uint32_t bound)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
/* 打开GPIO和USART部件的时钟 */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
/* 配置GPIO的模式和IO口 */
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_9; // 串口输出PA9(TX)
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz; // IO口频率
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP; // 复用推挽输出
GPIO_Init(GPIOA,&GPIO_InitStructure); // 初始化
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_10; // 串口输入PA10(RX)
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING;// 浮空输入
GPIO_Init(GPIOA,&GPIO_InitStructure); // 初始化
/* 配置串口硬件参数 */
USART_InitStructure.USART_BaudRate = bound; /* 波特率 */
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(USART1, &USART_InitStructure);
USART_ITConfig(USART1, USART_IT_IDLE, ENABLE); /* 使能串口空闲中断 */
USART_ClearFlag(USART1, USART_FLAG_TC | USART_FLAG_IDLE);
USART_Cmd(USART1, ENABLE); /* 使能串口 */
/* 开启串口收发DMA请求 */
USART_DMACmd(USART1,USART_DMAReq_Tx | USART_DMAReq_Rx,ENABLE);
/* 使能串口1中断 */
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/********************************************************************************************************
** 函数: USART1_DMA_Init, 串口1初始化。配置串口1的DMA，并开启DMA接收中断。
**------------------------------------------------------------------------------------------------------
** 参数: 无
** 返回: 无
********************************************************************************************************/
void USART1_DMA_Init(void)
{
DMA_InitTypeDef DMA_InitStructure;
/* 打开DMA通道时钟 */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);
DMA_DeInit(DMA1_Channel4);//TX 通道
DMA_DeInit(DMA1_Channel5);//RX 通道
/* TX 通道配置*/
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&USART1->DR);
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)usart1_tx_buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_BufferSize = 0;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel4,&DMA_InitStructure);
/* RX 通道配置*/
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&USART1->DR);
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)usart1_rx_buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = USART1_BUFF_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel5,&DMA_InitStructure);
/* 使能DMA收发通道 */
DMA_Cmd(DMA1_Channel4,ENABLE);
DMA_Cmd(DMA1_Channel5,ENABLE);
/* 这里没有使用DMA接收完成或者发送完成中断，如需要，可以在这里添加 */
}
/**
* @brief This function handles usart1 interrupt request.
* @param None
* @retval None
*/
void USART1_IRQHandler(void)
{
uint8_t ClearFlag;
uint16_t Count = 0;
/* 处理接收空闲中断 */
if (USART_GetITStatus(USART1, USART_IT_IDLE) != RESET)
{
/* 清除标志：先读SR，再读DR */
ClearFlag = USART1->SR;
ClearFlag = USART1->DR;
/* 获取接收数据个数 */
Count = DMA_GetCurrDataCounter(DMA1_Channel5);
usart1_tx_flag = USART1_BUFF_SIZE - Count;
/* 处理数据，这里用于演示，将收到的数据使用DMA发送出去 */
memcpy((uint8_t *)usart1_tx_buffer, (uint8_t *)usart1_rx_buffer, usart1_tx_flag);
/* DMA接收复位 */
DMA_Cmd(DMA1_Channel5,DISABLE);
DMA_SetCurrDataCounter(DMA1_Channel5,USART1_BUFF_SIZE);
DMA_Cmd(DMA1_Channel5,ENABLE);
}
}

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