参考博文
串口发送TX | PA9 | DMA2_Stream7 | 通道4 | 正常模式 |
---|
串口发送RX | PA10 | DMA2_Stream5 | 通道4 | 循环模式 |
串口波特率115200
PA9,PA10复用输出
注意点
串口接受数据dma方式不能开启串口接受中断
Dma双缓冲默认开启循环模式
Dma开启时需要确保相对应的标志位清零
仅在使能指针递增模式时允许突发模式
如果禁止数据流时仍有某些数据存留在FIFO 中, DMA 控制器会将剩余的数据继续传输到目标(即使已经有效禁止了数据流)。
以后再更USART串口空闲中断接受不定长数据
USART.h文件
#ifndef __MYUSART_H_
#define __MYUSART_H_
#include "stm32f4xx.h"
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include "LED.h"
#define TIMEOUT_MAX 10000
#define USART1_DR_BASE (USART1_BASE + 0X04)
#define USART1_BaudRate 115200
#define USART1_TX_GPIO_CLK RCC_AHB1Periph_GPIOA
#define USART1_TX_GPIO GPIOA
#define USART1_TX_Pin GPIO_Pin_9
#define USART1_TX_PinSource GPIO_PinSource9
#define USART1_RX_GPIO_CLK RCC_AHB1Periph_GPIOA
#define USART1_RX_GPIO GPIOA
#define USART1_RX_Pin GPIO_Pin_10
#define USART1_RX_PinSource GPIO_PinSource10
#define USART1_DMA_CLK RCC_AHB1Periph_DMA2
#define USART1_TX_DMAStream DMA2_Stream7
#define USART1_TX_DMA_Channel DMA_Channel_4
#define USART_TX_DMA_IRQn DMA2_Stream7_IRQn
#define USART1_RX_DMAStream DMA2_Stream5
#define USART1_RX_DMA_Channel DMA_Channel_4
#define USART_RX_DMA_IRQn DMA2_Stream5_IRQn
#define COMPLETE 1
#define UNCOMPLETE 0
#define SENDBUFF_SIZE 128
extern uint8_t USART1_SendBuff[SENDBUFF_SIZE];
extern uint8_t USART1_TX_FLAG;
#define RECEIVEBUFF_SIZE 64
extern uint8_t USART1_ReceiveBuff0[RECEIVEBUFF_SIZE];
extern uint8_t USART1_ReceiveBuff1[RECEIVEBUFF_SIZE];
void USART1_Init(void);
void USART1_printf(char *format, ...);
#endif
USART.C文件
#include "USART.h"
uint8_t USART1_SendBuff[SENDBUFF_SIZE] = {0};
uint8_t USART1_TX_FLAG = COMPLETE;
uint8_t USART1_ReceiveBuff0[RECEIVEBUFF_SIZE] = {0};
uint8_t USART1_ReceiveBuff1[RECEIVEBUFF_SIZE] = {0};
void USART1_Init(void)
{
__IO uint16_t Timeout = TIMEOUT_MAX;
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_AHB1PeriphClockCmd(USART1_TX_GPIO_CLK|USART1_RX_GPIO_CLK, ENABLE);
GPIO_InitStructure.GPIO_Pin = USART1_TX_Pin;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(USART1_TX_GPIO, &GPIO_InitStructure);
RCC_AHB1PeriphClockCmd(USART1_RX_GPIO_CLK, ENABLE);
GPIO_InitStructure.GPIO_Pin = USART1_RX_Pin;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(USART1_RX_GPIO, &GPIO_InitStructure);
GPIO_PinAFConfig(USART1_TX_GPIO, USART1_TX_PinSource, GPIO_AF_USART1);
GPIO_PinAFConfig(USART1_RX_GPIO, USART1_RX_PinSource, GPIO_AF_USART1);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
USART_InitStructure.USART_BaudRate = USART1_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_Mode = USART_Mode_Rx|USART_Mode_Tx;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_Init(USART1, &USART_InitStructure);
USART_DMACmd(USART1, USART_DMAReq_Tx, ENABLE);
USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);
RCC_AHB1PeriphClockCmd(USART1_DMA_CLK, ENABLE);
DMA_DeInit(USART1_TX_DMAStream);
while(DMA_GetCmdStatus(USART1_TX_DMAStream) == ENABLE);
DMA_InitStructure.DMA_Channel = USART1_TX_DMA_Channel;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)USART1_DR_BASE;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)USART1_SendBuff;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_BufferSize = SENDBUFF_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_INC16;
DMA_Init(USART1_TX_DMAStream, &DMA_InitStructure);
RCC_AHB1PeriphClockCmd(USART1_DMA_CLK, ENABLE);
DMA_DeInit(USART1_RX_DMAStream);
while(DMA_GetCmdStatus(USART1_RX_DMAStream) == ENABLE);
DMA_InitStructure.DMA_Channel = USART1_RX_DMA_Channel;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)USART1_DR_BASE;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)USART1_ReceiveBuff0;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = RECEIVEBUFF_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_INC16;
DMA_DoubleBufferModeConfig(USART1_RX_DMAStream, (uint32_t)USART1_ReceiveBuff1, DMA_Memory_0);
DMA_DoubleBufferModeCmd(USART1_RX_DMAStream, ENABLE);
DMA_Init(USART1_RX_DMAStream, &DMA_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = USART_TX_DMA_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
DMA_ITConfig(USART1_TX_DMAStream, DMA_IT_TC, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = USART_RX_DMA_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
DMA_ITConfig(USART1_RX_DMAStream, DMA_IT_TC, ENABLE);
DMA_Cmd(USART1_RX_DMAStream, ENABLE);
Timeout = TIMEOUT_MAX;
while(DMA_GetCmdStatus(USART1_RX_DMAStream) == DISABLE && Timeout-- > 0);
if(Timeout == 0)
{
while(1)
{
LED_R = ~LED_R;
Delay_ms(500);
}
}
USART_Cmd(USART1, ENABLE);
}
static void USART1_DMA_Send(uint16_t length)
{
while(USART1_TX_FLAG != COMPLETE)
{
}
USART1_TX_FLAG = UNCOMPLETE;
DMA_SetCurrDataCounter(USART1_TX_DMAStream, length);
DMA_Cmd(USART1_TX_DMAStream, ENABLE);
}
void USART1_printf(char *format, ...)
{
va_list arg_ptr;
va_start(arg_ptr, format);
vsnprintf((char*)USART1_SendBuff, SENDBUFF_SIZE + 1, format, arg_ptr);
va_end(arg_ptr);
USART1_DMA_Send(strlen((const char*)USART1_SendBuff));
}
中断函数
void DMA2_Stream7_IRQHandler(void)
{
if(DMA_GetITStatus(USART1_TX_DMAStream, DMA_IT_TCIF7))
{
DMA_ClearITPendingBit(USART1_TX_DMAStream, DMA_IT_TCIF7);
USART1_TX_FLAG = COMPLETE;
}
}
void DMA2_Stream5_IRQHandler(void)
{
if(DMA_GetITStatus(USART1_RX_DMAStream, DMA_IT_TCIF5))
{
DMA_ClearITPendingBit(USART1_RX_DMAStream, DMA_IT_TCIF5);
LED_B = ~LED_B;
}
}
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