STM32：DMA实例之串口(USART)通信

硬件平台：stm32f10xZET6
开发环境：keil MDK uVision v4.10
开发语言：C、ST_lib_3.5固件库

/*代码演示main.c*/

#include"stm32f10x.h"

#include"bsp_usart1.h"

#include"bsp_led.h"

externuint8_tSendBuff[SENDBUFF_SIZE];

staticvoidDelay(__IOu32nCount);

/**

*@brief主函数

*/

intmain(void)

{

/*USART1config1152008-N-1*/

USART1_Config();

USART1_DMA_Config();

LED_GPIO_Config();

printf("rnusart1DMATXtest...rn");

{

uint16_ti;

/*填充将要发送的数据*/

for(i=0;i

{

SendBuff[i]='a';//打字母a仅做演示

}

}

/*USART1向DMA发出TX请求*/

USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE);

/*此时CPU是空闲的，可以干其他的事情*/

//例如同时控制LED

for(;;)

{

LED1(ON);

Delay(0xFFFFF);

LED1(OFF);

Delay(0xFFFFF);

}

}

staticvoidDelay(__IOuint32_tnCount)//简单的延时函数

{

for(;nCount!=0;nCount--);

}

/*中断处理函数stm32f10x_it.cline:157*/

voidDMA1_Channel4_IRQHandler(void)

{

//判断是否为DMA发送完成中断

if(DMA_GetFlagStatus(DMA1_FLAG_TC4)==SET)

{

//LED关闭

LED1(OFF);

DMA_ClearFlag(DMA1_FLAG_TC4);

}

}

/*代码演示bsp_usart1模块*/

#ifndef__USART1_H

#define__USART1_H

#include"stm32f10x.h"

#include

#defineUSART1_DR_Base0x40013804//0x40013800+0x04=0x40013804

#defineSENDBUFF_SIZE5000

voidUSART1_Config(void);

voidUSART1_DMA_Config(void);

#endif/*__USART1_H*/

//------------------------------------------------------

#include"bsp_usart1.h"

uint8_tSendBuff[SENDBUFF_SIZE];

/**

*@briefUSART1GPIO配置,工作模式配置。1152008-N-1

*@param无

*@retval无

*/

voidUSART1_Config(void)

{

GPIO_InitTypeDefGPIO_InitStructure;

USART_InitTypeDefUSART_InitStructure;

/*configUSART1clock*/

RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA,ENABLE);

/*USART1GPIOconfig*/

/*ConfigureUSART1Tx(PA.09)asalternatefunctionpush-pull*/

GPIO_InitStructure.GPIO_Pin=GPIO_Pin_9;

GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;

GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;

GPIO_Init(GPIOA,&GPIO_InitStructure);

/*ConfigureUSART1Rx(PA.10)asinputfloating*/

GPIO_InitStructure.GPIO_Pin=GPIO_Pin_10;

GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING;

GPIO_Init(GPIOA,&GPIO_InitStructure);

/*USART1modeconfig*/

USART_InitStructure.USART_BaudRate=115200;

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_Rx|USART_Mode_Tx;

USART_Init(USART1,&USART_InitStructure);

USART_Cmd(USART1,ENABLE);

}

/**

*@briefUSART1TXDMA配置，内存到外设(USART1->DR)

*@param无

*@retval无

*/

voidUSART1_DMA_Config(void)

{

DMA_InitTypeDefDMA_InitStructure;

/*开启DMA时钟*/

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);

/*传输大小DMA_BufferSize=SENDBUFF_SIZE*/

DMA_InitStructure.DMA_BufferSize=SENDBUFF_SIZE;//此处是发送的buffer的配置

/*方向：从内存到外设*/

DMA_InitStructure.DMA_DIR=DMA_DIR_PeripheralDST;

/*禁止内存到内存的传输*/

DMA_InitStructure.DMA_M2M=DMA_M2M_Disable;

/*内存地址(要传输的变量的指针)*/

DMA_InitStructure.DMA_MemoryBaseAddr = (u32)SendBuff;