STM32Fxx之串口DMA配置

只看该作者 · 2024-3-31 23:52

简介：
串口高波特率通讯时需要用DMA传输数据。本文档串口DMA驱动采样stm32标准库版本。

1、时钟配置
//时钟配置
static void USART_RCC_Config(void)
{
//使能DMA外设
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

//使能GPIO时钟
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

//使能串口时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

//使能系统时钟配置
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
}

只看该作者 · 2024-3-31 23:53

串口GPIO配置
//串口GPIO配置
static void USART_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

//usart引脚配置
GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_1);

//配置 Tx pins
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);

//配置Rx pins
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}

只看该作者 · 2024-3-31 23:53

初始化串口1
//初始化串口1
void USART1_Init(uint32_t baudrate)
{
USART_InitTypeDef USART_InitStructure;
DMA_InitTypeDef DMA_InitStructure;

//使能外设时钟
USART_RCC_Config();

//配置串口GPIO
USART_GPIO_Config();

//DMA映射串口的发送与接收
DMA_RemapConfig(DMA1，DMA1_CH2_USART1_TX);
DMA_RemapConfig(DMA1，DMA1_CH3_USART1_RX);

USART_OverSampling8cmd(USART1, ENABLE); //高波特率开启8bit过采样

USART_InitStructure.USART_BaudRate = baudrate;
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_Tx | USART_Mode_Rx;
USART_Init(USART1, &USART_InitStructure);

//DMA配置
DMA_InitStructure.DMA_BufferSize = MAX_LEN;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoreDataSize_Byte;
DMA_InitStructure.DMA_PeripheralInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

//DMA1 channel2配置
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)test_buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
DMA_InitStructure.DMA_PeripheralBaseAddr = USART1_TDR_Address;
DMA_Init(DMA1_Channel2, &DMA_InitStructure);

//DMA1 channel3配置
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)test_buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_Priority = DMA_Priority_Low;
DMA_InitStructure.DMA_PeripheralBaseAddr = USART1_RDR_Address;
DMA_Init(DMA1_Channel3, &DMA_InitStructure);

//clear DMA1 TC flag
DMA_ClearFlag(DMA1_FLAG_TC2);
DMA_ClearFlag(DMA1_FLAG_TC3);

//使能串口发送接收请求
USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);

//使能DMA通道
DMA_Cmd(DMA1_Channel2, ENABLE);
DMA_Cmd(DMA1_Channel3, ENABLE);

//使能串口
USART_Cmd(USART1, ENABLE);
}

只看该作者 · 2024-3-31 23:53

串口DMA发送
void USART1_DMA_Send(uint8_t *buff, uint16_t len)
{
//失能DMA1通道
DMA_Cmd(DMA1_Channel2, DISABLE);

//clear DMA1 TC flags
DMA_ClearFlag(DAM1_FLAG_TC2);
DMA_SetCurrDataCounter(DMA1_Channel2, len);
USART_DMACmd(USART1, USART_DMAReq_Tx, ENABLE);

DMA_Cmd(DMA1_Channel2, ENABLE);

while(RESET == DMA_GetFlagStatus(DMA1_FLAG_TC2)){}
}

只看该作者 · 2024-3-31 23:53

串口ＤＭＡ接收
void USART1_DMA_Receive(void)
{
//失能DMA1通道
DMA_Cmd(DMA1_Channel3, DISABLE);

//clear DMA1 TC flags
DMA_ClearFlag(DAM1_FLAG_TC3);
DMA_SetCurrDataCounter(DMA1_Channel3, MAX_LEN);
USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);

DMA_Cmd(DMA1_Channel3, ENABLE);
}