2020年10月09日 | STM32的串口采用DMA方式发送数据测试

环境：

主机:WIN7

开发环境:MDK4.23

MCU:STM32F103CBT6

源代码:

配置:

//---------------------串口功能配置---------------------

//打开串口对应的外设时钟  

RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 , ENABLE);   

//启动DMA时钟

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

//DMA发送中断设置

NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

//DMA1通道4配置

DMA_DeInit(DMA1_Channel4);

//外设地址

DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)(&USART1->DR);

//内存地址

DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)Uart_Send_Buffer;

//dma传输方向单向

DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;

//设置DMA在传输时缓冲区的长度

DMA_InitStructure.DMA_BufferSize = 100;

//设置DMA的外设递增模式，一个外设

DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

//设置DMA的内存递增模式

DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

//外设数据字长

DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

//内存数据字长

DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_Byte;

//设置DMA的传输模式

DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;

//设置DMA的优先级别

DMA_InitStructure.DMA_Priority = DMA_Priority_High;

//设置DMA的2个memory中的变量互相访问

DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

DMA_Init(DMA1_Channel4,&DMA_InitStructure);

DMA_ITConfig(DMA1_Channel4,DMA_IT_TC,ENABLE);

//使能通道4

//DMA_Cmd(DMA1_Channel4, ENABLE);

//初始化参数  

//USART_InitStructure.USART_BaudRate = DEFAULT_BAUD;  

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 = DEFAULT_BAUD; 

//初始化串口 

USART_Init(USART1,&USART_InitStructure);  

//TXE发送中断,TC传输完成中断,RXNE接收中断,PE奇偶错误中断,可以是多个   

USART_ITConfig(USART1,USART_IT_RXNE,ENABLE);  

//配置UART1中断  

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3);

NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;               //通道设置为串口1中断  

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;       //中断占先等级0  

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;              //中断响应优先级0  

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                 //打开中断  

NVIC_Init(&NVIC_InitStructure);                                 //初始化  

//采用DMA方式发送

USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE);

//启动串口  

USART_Cmd(USART1, ENABLE);   

//设置IO口时钟      

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);    

//串口1的管脚初始化    

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;                       //管脚9  

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;                //选择GPIO响应速度  

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;                 //复用推挽输出  

GPIO_Init(GPIOA, &GPIO_InitStructure);                          //TX初始化  

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;                      //管脚10  

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;                //选择GPIO响应速度  

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;           //浮空输入  

GPIO_Init(GPIOA, &GPIO_InitStructure);                          //RX初始化                                                      

//设置IO口时钟      

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);   

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;                       //管脚9  

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;                //选择GPIO响应速度  

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;                 //复用推挽输出  

中断函数：

//串口1DMA方式发送中断

void DMA1_Channel4_IRQHandler(void)

{

//清除标志位

  DMA_ClearFlag(DMA1_FLAG_TC4);

//DMA_ClearITPendingBit(DMA1_FLAG_TC4);

  //DMA1->IFCR |= DMA1_FLAG_TC4;

//关闭DMA

DMA_Cmd(DMA1_Channel4,DISABLE);

  //DMA1_Channel4->CCR &= ~(1<<0);

//允许再次发送

Flag_Uart_Send = 0;

}

发送测试：

//串口DMA发送测试

Uart_Send_Buffer[0] = 1;

Uart_Send_Buffer[1] = 2;

Uart_Send_Buffer[2] = 3;

Uart_Send_Buffer[3] = 4;

Uart_Send_Buffer[4] = 5;

i = 1;

while (1)

{

//检查串口是否可以发送

while (Flag_Uart_Send);

Flag_Uart_Send = 1;

//设置传输数据长度

DMA_SetCurrDataCounter(DMA1_Channel4,i);

//打开DMA

DMA_Cmd(DMA1_Channel4,ENABLE);

i++;

if (i > 5)

{

i = 1;

}

}