STM32F103 UART4 DMA接收 终于调试成功，分享一下

//网上找了老半天也找不到UART4-DMA的程序，自己调试成功了，特地分享一下

</pre><pre name="code" class="cpp"><pre name="code" class="cpp">uint8_t UART4_Rx_buffer[512],UART4_Rx_num;

void UART4_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
DMA_InitTypeDef DMA_InitStructure;	 //定义DMA初始化结构体DMA_InitStructure

//	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); 	 //选择NVIC优先级分组0
RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);

//串口4所使用管脚输出输入定义

//定义UART4 Tx (PC.10)脚为复用推挽输出
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;         //IO口的第2脚
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //IO口速度
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;   //IO口复用推挽输出
GPIO_Init(GPIOC, &GPIO_InitStructure);            //初始化串口1输出IO口

//定义 UART4 Rx (PC.11)为悬空输入
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;           //IO口的第3脚
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//IO口悬空输入
GPIO_Init(GPIOC, &GPIO_InitStructure);               //初始化串口1输入IO口

//串口4参数初始化定义部分,串口1参数为9600 ， 8 ，1 ，N  接收中断方式
USART_InitStructure.USART_BaudRate = 9600;                  //设定传输速率
USART_InitStructure.USART_WordLength = USART_WordLength_8b; //设定传输数据位数
USART_InitStructure.USART_StopBits = USART_StopBits_1;      //设定停止位个数
USART_InitStructure.USART_Parity = USART_Parity_No ;        //不用校验位
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//不用流量控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;                //使用接收和发送功能
USART_Init(UART4, &USART_InitStructure);      //初始化串口4

USART_ITConfig(UART4, USART_IT_IDLE,ENABLE);  //使能串口4接收中断
USART_Cmd(UART4, ENABLE);                     //使能串口4
USART_ClearFlag(UART4, USART_FLAG_TC);        // 清标志(后增加)

DMA_DeInit(DMA2_Channel3);	 //重置DMA 2通道配置
DMA_InitStructure.DMA_PeripheralBaseAddr = 0x40004C04;	 //外设地址
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)UART4_Rx_buffer;	 //内存地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;	 //外设作为数据目的地
DMA_InitStructure.DMA_BufferSize = 512;	 //DMA缓存大小:BufferSize
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;	 //外设地址寄存器不递增
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;	  	 //内存地址寄存器递增
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; 	//外设数据宽度为8位
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_Byte;	 //内存数据宽度为8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;	 //工作在正常缓存模式
DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;	 //设置DMA通道优先级为高
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;	 //禁止DMA通道设置为内存至内存传输
DMA_Init(DMA2_Channel3, &DMA_InitStructure);	 //初始化

DMA_ITConfig(DMA2_Channel3, DMA_IT_TC, ENABLE);
DMA_ITConfig(DMA2_Channel3, DMA_IT_TE, ENABLE);

USART_DMACmd(UART4, USART_DMAReq_Rx, ENABLE);
DMA_Cmd(DMA2_Channel3, ENABLE);
//使能串口4中断
NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = DMA2_Channel3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

void UART4_IRQHandler(void)
{
<span style="white-space:pre">	</span>uint16_t i;
<span style="white-space:pre">	</span>uint16_t Data_Len;
<span style="white-space:pre">	</span>if(USART_GetITStatus(UART4, USART_IT_IDLE) != RESET)    //如果为中断
<span style="white-space:pre">	</span>{  
<span style="white-space:pre">		</span>DMA_Cmd(DMA2_Channel3, DISABLE);
<span style="white-space:pre">		</span>Data_Len=512-DMA_GetCurrDataCounter(DMA2_Channel3);
<span style="white-space:pre">		</span>USART_PutStr(USART1,UART4_Rx_buffer,Data_Len);<span style="white-space:pre">		</span><span style="white-space:pre">		</span>
<span style="white-space:pre">		</span>UART4_Rx_num=0;
<span style="white-space:pre">		</span>DMA_ClearFlag(DMA2_FLAG_GL3 | DMA2_FLAG_TC3 | DMA2_FLAG_TE3 | DMA2_FLAG_HT3); //清标志
<span style="white-space:pre">		</span>DMA2_Channel3->CNDTR = 512;                //重装填
<span style="white-space:pre">		</span>DMA_Cmd(DMA2_Channel3, ENABLE);            //处理完,重开DMA
<span style="white-space:pre">		</span>//读SR后读DR清除IDLE
<span style="white-space:pre">		</span>i = UART4->SR;
<span style="white-space:pre">		</span>i = UART4->DR;
<span style="white-space:pre">		</span>if(i)<span style="white-space:pre">			</span>i=0;
<span style="white-space:pre">		</span>if(Data_Len)<span style="white-space:pre">	</span>Data_Len=0;   
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>if(USART_GetITStatus(UART4, USART_IT_PE | USART_IT_FE | USART_IT_NE) != RESET){    //出错
<span style="white-space:pre">		</span>USART_ClearITPendingBit(UART4, USART_IT_PE | USART_IT_FE | USART_IT_NE);
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>USART_ClearITPendingBit(UART4, USART_IT_TC);
<span style="white-space:pre">	</span>USART_ClearITPendingBit(UART4, USART_IT_IDLE);<span style="white-space:pre">	</span>
}

void DMA2_Channel3_IRQHandler(void)
{<pre name="code" class="cpp"><span style="white-space:pre">	</span>USART_PutStr(USART1," DMA23:\r\n",9);
<span>	</span>DMA_ClearITPendingBit(DMA2_IT_TC3);
<span>	</span>DMA_ClearITPendingBit(DMA2_IT_TE3);
<span>	</span>DMA_Cmd(DMA2_Channel3, DISABLE);         //关闭DMA,防止处理其间有数据
<span>	</span>DMA2_Channel3->CNDTR = 512;              //重装填
<span>	</span>DMA_Cmd(DMA2_Channel3, ENABLE);          //处理完,重开DMA
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