//串口接收DMA缓存
#define UART_RX_LEN
128
/****************static*****************/
//串口接收DMA缓存
static uint8_t Uart_Rx[UART_RX_LEN] = {
0};
/****************extern*****************/
extern uart_recv_s uart_recv[
2];
extern uint8_t uart_recv_flag;
static
void DMA_config()
{
DMA_InitTypeDef DMA_InitStructure;
//串口收DMA配置
//启动DMA时钟
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
//DMA1通道5配置
DMA_DeInit(DMA1_Channel3);
//外设地址
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&USART1->RDR);
//内存地址
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)Uart_Rx;
//dma传输方向单向
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
//设置DMA在传输时缓冲区的长度
DMA_InitStructure.DMA_BufferSize = UART_RX_LEN;
//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_MemoryDataSize_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_VeryHigh;
//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_Channel3,&DMA_InitStructure);
//使能通道5
DMA_Cmd(DMA1_Channel3,ENABLE);
}
//---------------------串口功能配置---------------------
void USART1_DMA_Config() {
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
//定义串口初始化结构体
NVIC_InitTypeDef NVIC_InitStruct;
RCC_AHBPeriphClockCmd(USART1_GPIO_RCC, ENABLE);
//使能GPIOA的时钟
RCC_APB2PeriphClockCmd(USART1_RCC, ENABLE);
//使能USART的时钟
GPIO_PinAFConfig(USART1_GPIO_PORT, USART1_TX_GPIO_PinSource, GPIO_AF_1);
//配置PA9成第二功能引脚 TX
GPIO_PinAFConfig(USART1_GPIO_PORT, USART1_RX_GPIO_PinSource, GPIO_AF_1);
//配置PA10成第二功能引脚 RX
/*USART1_TX ->PA9 USART1_RX ->PA10*/
GPIO_InitStructure.GPIO_Pin = USART1_TX|USART1_RX;
//选中串口默认输出管脚
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
//定义输出最大速率
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
//定义管脚9的模式
GPIO_Init(USART1_GPIO_PORT, &GPIO_InitStructure);
//调用函数，把结构体参数输入进行初始化
DMA_config();
/*串口通讯参数设置*/
USART_InitStructure.USART_BaudRate = UART1_BaudRate;
//9600; //波特率
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
//数据位8位
USART_InitStructure.USART_StopBits = USART_StopBits_1;
//停止位1位
USART_InitStructure.USART_Parity = USART_Parity_No;
//校验位 无
USART_InitStructure.USART_HardwareFlowCOntrol= USART_HardwareFlowControl_None;
//无流控制
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
//使能接收和发送引脚
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_TC,DISABLE);
USART_ITConfig(USART1,USART_IT_IDLE,ENABLE);
USART1->ICR |=
1<<
4;
//必须先清除IDLE中断，否则会一直进IDLE中断
USART_ITConfig(USART1, USART_IT_RXNE, DISABLE);
//采用DMA方式发送
//USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE);
//采用DMA方式接收
USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);
USART_Cmd(USART1, ENABLE);
/* USART1的NVIC中断配置 */
NVIC_InitStruct.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStruct.NVIC_IRQChannelPriority =
0x02;
NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStruct);
}
//串口1接收中断
void USART1_IRQHandler(
void)
{
uint16_t Len =
0;
if(USART_GetITStatus(USART1, USART_IT_IDLE) != RESET)
{
USART1->ICR |=
1<<
4;
//清除中断
DMA_Cmd(DMA1_Channel3,DISABLE);
Len = UART_RX_LEN - DMA_GetCurrDataCounter(DMA1_Channel3);
if (Len
memcpy(uart_recv[UART_1].recv_buf, Uart_Rx, Len);
uart_recv[UART_1].count = Len;
}
else {
memcpy(uart_recv[UART_1].recv_buf, Uart_Rx, UART_BUF_LEN);
uart_recv[UART_1].count = UART_BUF_LEN;
}
uart_recv_flag =
1;
//设置传输数据长度
DMA_SetCurrDataCounter(DMA1_Channel3,UART_RX_LEN);
//打开DMA
DMA_Cmd(DMA1_Channel3,ENABLE);
}
}
在中断中计算接收到的数据长度并通知应用层读取数据
配置DMA通道：查找手册看USART1_RX对应的DMA通道
配置DMA外设寄存器地址，接收时即UARTT1的接收数据寄存器的地址：
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