1.基本信息
USART2：256000，8,1,no parity,
DMA_TX:DMA1_Stream6,Direct mode,normal mode...
DMA_RX:DMA1_Stream5,Double buffer,circular mode...
2.详细代码
(1)串口usart2及DMA初始化
void Usart2DmaInit(void)
{
NVIC_InitTypeDef NVIC_InitStructure ;
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
//设置IO口及时钟
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
GPIO_PinAFConfig(GPIOD, GPIO_PinSource5, GPIO_AF_USART2);
GPIO_PinAFConfig(GPIOD, GPIO_PinSource6, GPIO_AF_USART2);
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/////////////////////////////////////////////////////////////////////////
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
/////////////////////////////////////////////////////////////////////////
//串口收DMA配置
DMA_DeInit(DMA1_Stream5);
DMA_InitStructure.DMA_Channel = DMA_Channel_4;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&(USART2)->DR);
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)(UART2_DMA_RX0);
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = UART_RX_BUFFER_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_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;
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); //配置DMA1的通道
DMA_MemoryTargetConfig(DMA1_Stream5,(uint32_t)UART2_DMA_RX1,DMA_Memory_1);
DMA_Cmd(DMA1_Stream5,ENABLE); //使能DMA接收通道
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream5_IRQn; //通道设置为串口中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //中断占先等级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //中断响应优先级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //打开中断
NVIC_Init(&NVIC_InitStructure);
//////////////////////////////////////////////////////////////////////////////////
//串口发DMA配置
DMA_DeInit(DMA1_Stream6); //DMA通道配置
DMA_InitStructure.DMA_Channel = DMA_Channel_4; //DMA发送通道
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&(USART2)->DR); //外设地址
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)UART2_DMA_TX; //内存地址
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral; //dma传输方向
DMA_InitStructure.DMA_BufferSize = 100; //设置DMA在传输时缓冲区的长度
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //设置DMA的外设递增模式，一个外设
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //设置DMA的内存递增模式
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //外设数据字长
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_Byte; //内存数据字长
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //设置DMA的传输模式
DMA_InitStructure.DMA_Priority = DMA_Priority_High; //设置DMA的优先级别
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; //指定如果FIFO模式或直接模式将用于指定的流 ： 不使能FIFO模式
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull; //指定了FIFO阈值水平 DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single; //指定的Burst转移配置内存传输
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single; //指定的Burst转移配置外围转移 //
DMA_Init(DMA1_Stream6, &DMA_InitStructure); //配置DMAx的通道
DMA_ITConfig(DMA1_Stream6,DMA_IT_TC,ENABLE); //使能中断
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream6_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
///////////////////////////////////////////////////////////////////////////////
//串口参数配置
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_InitStructure.USART_BaudRate = 256000;
USART_Init(USART2,&USART_InitStructure);
//配置中断
NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; //通道设置为串口中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //中断占先等级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //中断响应优先级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //打开中断
NVIC_Init(&NVIC_InitStructure);
USART_DMACmd(USART2,USART_DMAReq_Tx,ENABLE);
USART_DMACmd(USART2,USART_DMAReq_Rx,ENABLE);
//中断配置
USART_ITConfig(USART2,USART_IT_TC,DISABLE);
USART_ITConfig(USART2,USART_IT_RXNE,DISABLE);
USART_ITConfig(USART2,USART_IT_TXE,DISABLE);
USART_ITConfig(USART2,USART_IT_IDLE,DISABLE);
USART_Cmd(USART2, ENABLE);
}
(2)DMA接收中断
void DMA1_Stream5_IRQHandler(void) // uart2 rx
{
if (DMA_GetITStatus(DMA1_Stream5, DMA_IT_TCIF5) != RESET)
{
DMA_ClearITPendingBit(DMA1_Stream5, DMA_IT_TCIF5);
}
if (DMA_GetITStatus(DMA1_Stream5, DMA_IT_TEIF5) != RESET)
{
DMA_ClearITPendingBit(DMA1_Stream5, DMA_IT_TEIF5);
}
}
(3)DMA发送中断
void DMA1_Stream6_IRQHandler(void) //com6 uart2 tx
{
if (DMA_GetITStatus(DMA1_Stream6, DMA_IT_TCIF6) != RESET) //transfer complete interrupt flag
{
DMA_ClearITPendingBit(DMA1_Stream6, DMA_IT_TCIF6);
DMA_Cmd(DMA1_Stream6,DISABLE); // stop DMA transmit
Tmpbsy = 0;
USART_ITConfig(USART1,USART_IT_TC,ENABLE); //open usart transfer complete interrupt,to send the last 2 bytes.
}
if (DMA_GetITStatus(DMA1_Stream6, DMA_IT_HTIF6) != RESET) //half transfer interrupt flag
{
DMA_ClearITPendingBit(DMA1_Stream6, DMA_IT_HTIF6);
}
}
(4)主循环
void main(void)
{
//Initilized functions
//...
//...
while(1)
{
if(Tmpbsy==0)
{
Tmpbsy = 1;
DMA_SetCurrDataCounter(DMA1_Stream6,100);
DMA_Cmd(DMA1_Stream6,ENABLE);
}
}
} |
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