STM32串口4接收DMA
STM32串口4接收DMA+闲时中断
void uart4_init(u32 bound)
{
GPIO_InitTypeDefGPIO_InitStructure;
USART_InitTypeDefUSART_InitStructure;
NVIC_InitTypeDefNVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_UART4, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE); //使能UART4，GPIOA时钟
//UART4_TX GPIOC.10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; //PC.10
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_Init(GPIOC, &GPIO_InitStructure);//初始化GPIOC.10
//UART4_RX GPIOC.11初始化
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;//PC11
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//浮空输入
GPIO_Init(GPIOC, &GPIO_InitStructure);//初始化GPIOC11
//Uart4 NVIC 配置
NVIC_InitStructure.NVIC_IRQChannel = UART4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//抢占优先级3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //子优先级3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
//IRQ通道使能
NVIC_Init(&NVIC_InitStructure); //根据指定的参数初始化VIC 寄存器
//USART 初始化设置
USART_https://www.wendangku.net/doc/4d18928156.html,ART_BaudRate = bound;//串口波特率USART_https://www.wendangku.net/doc/4d18928156.html,ART_WordLength = USART_WordLength_8b;//字长为8位数据格式
USART_https://www.wendangku.net/doc/4d18928156.html,ART_StopBits = USART_StopBits_1;//一个停止位
USART_https://www.wendangku.net/doc/4d18928156.html,ART_Parity = USART_Parity_No;//无奇偶校验位
USART_https://www.wendangku.net/doc/4d18928156.html,ART_HardwareFlowControl = USART_HardwareFlowControl_None;//无硬件数据流控制USART_https://www.wendangku.net/doc/4d18928156.html,ART_Mode =USART_Mode_Tx|
USART_Mode_Rx; //收发模式
USART_Init(UART4, &USART_InitStructure); //初始化串口4
USART_ITConfig(UART4, USART_IT_IDLE, ENABLE);
USART_DMACmd(UART4,USART_DMAReq_Rx,ENABLE);
USART_Cmd(UART4, ENABLE); //使能串口4
}
void MYDMA_Config(DMA_Channel_TypeDef* DMA_CHx,u32 cpar,u32 cmar,u16 cndtr)
{
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE); //使能DMA传输
DMA_DeInit(DMA_CHx); //将DMA的通道1寄存器重设为缺省值
DMA1_MEM_LEN=cndtr;
DMA_InitStructure.DMA_PeripheralBaseAddr = cpar; //DMA 外设基地址
DMA_InitStructure.DMA_MemoryBaseAddr =cmar; //DMA内存基地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; //
外设作为数据源，从外设发到片内
DMA_InitStructure.DMA_BufferSize = cndtr; //DMA通道的DMA缓存的大小
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //外设地址寄存器不变
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_MemoryDataSize_Byte; //数据宽度为8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //工作在正常缓存模式
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; //DMA通道x拥有中优先级
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA 通道x没有设置为内存到内存传输
DMA_Init(DMA_CHx, &DMA_InitStructure); //根据DMA_InitStruct中指定的参数初始化DMA的通道USART1_Tx_DMA_Channel所标识的寄存器
DMA_Cmd(DMA_CHx, DISABLE); //关闭UART4 TX DMA1
所指示的通道
DMA_SetCurrDataCounter(DMA_CHx,DMA1_MEM_LEN);//DM A通道的DMA缓存的大小
DMA_Cmd(DMA_CHx, ENABLE); //使能UART4 TX DMA2 所指示的通道
}
void UART4_IRQHandler(void) //串口4中断服务程序
{
unsigned char num=0;
if(USART_GetITStatus(UART4,USART_IT_IDLE) == SET)
{
num = UART4->SR; //先读SR，再读DR才能清楚标志位
num = UART4->DR; //SR、DR赋值清标志位，清USART_IT_IDLE 标志
DMA_Cmd(DMA2_Channel3, DISABLE); //关闭DMA
num = DMA_GetCurrDataCounter(DMA2_Channel3); //得到真正接收数据个数
DMA2_Channel3->CNDTR=20; //重新设置接收数据个数
DMA_Cmd(DMA2_Channel3,ENABLE); //开启DMA }
}
void main(void)
{
MYDMA_Config(DMA2_Channel3,(u32)&UART4->DR,(u32)data,2 0);
//初始化串口4DMA
}