STM32单片机DMA实验

DMA配置的一般步骤：

①：使能DMA时钟

RCC_AHBPeriphClockCmd();

②：初始化DMA通道参数：

DMA_Init();

③：使能串口DMA发送，串口DMA使能函数

USART_DMACmd();

④：使能DMA1通道，启动传输。

DMA_Cmd();

⑤：查询DMA传输状态：

DMA_GetFlagStatus();

⑥：获取/设置通道当前剩余数据量：

DMA_GetCurrDataConuter();

DMA_SetCurrDataCounter();

先写.h文件

#ifndef __DMA_H
#define	__DMA_H	   
#include "sys.h"
void MYDMA_Config(DMA_Channel_TypeDef*DMA_CHx,u32 cpar,u32 cmar,u16 cndtr);
void MYDMA_Enable(DMA_Channel_TypeDef*DMA_CHx);	   
#endif

再写.c文件

#include "dma.h"
DMA_InitTypeDef DMA_InitStructure;
u16 DMA1_MEM_LEN;
void MYDMA_Config(DMA_Channel_TypeDef* DMA_CHx,u32 cpar,u32 cmar,u16 cndtr)
{
 	RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
  DMA_DeInit(DMA_CHx);
	DMA1_MEM_LEN=cndtr;
	DMA_InitStructure.DMA_PeripheralBaseAddr = cpar;  
	DMA_InitStructure.DMA_MemoryBaseAddr = cmar;
	DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST; 
	DMA_InitStructure.DMA_BufferSize = cndtr; 
	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_MemoryDataSize_Byte;
	DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
	DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
	DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
	DMA_Init(DMA_CHx, &DMA_InitStructure);
} 
void MYDMA_Enable(DMA_Channel_TypeDef*DMA_CHx)
{ 
	DMA_Cmd(DMA_CHx, DISABLE );   
 	DMA_SetCurrDataCounter(DMA_CHx,DMA1_MEM_LEN);
 	DMA_Cmd(DMA_CHx, ENABLE);  
}	  

 

最后写.main函数

#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "lcd.h"
#include "usart.h"	 
#include "dma.h"
#define SEND_BUF_SIZE 8200
u8 SendBuff[SEND_BUF_SIZE];
const u8 TEXT_TO_SEND[]={"ALIENTEK Elite STM32F1 DMA ´®¿ÚʵÑé"};
 int main(void)
 {	 
	u16 i;
	u8 t=0;
	u8 j,mask=0;
	float pro=0;
	delay_init();	    
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	uart_init(115200);
	LED_Init();	
	LCD_Init();
	KEY_Init();		 	
 	MYDMA_Config(DMA1_Channel4,(u32)&USART1->DR,(u32)SendBuff,SEND_BUF_SIZE);
 	POINT_COLOR=RED;
	LCD_ShowString(30,50,200,16,16,"Elite STM32");	
	LCD_ShowString(30,70,200,16,16,"DMA TEST");	
	LCD_ShowString(30,90,200,16,16,"ATOM@ALIENTEK");
	LCD_ShowString(30,110,200,16,16,"2015/1/15");	
 	LCD_ShowString(30,130,200,16,16,"KEY0:Start");
	j=sizeof(TEXT_TO_SEND);	   
	for(i=0;i<SEND_BUF_SIZE;i++)
    {
		if(t>=j)
		{
			if(mask)
			{
				SendBuff[i]=0x0a;
				t=0;
			}else 
			{
				SendBuff[i]=0x0d;
				mask++;
			}	
		}else
		{
			mask=0;
			SendBuff[i]=TEXT_TO_SEND[t];
			t++;
		}    	   
    }		 
	POINT_COLOR=BLUE; 
	i=0;
	while(1)
	{
		t=KEY_Scan(0);
		if(t==KEY0_PRES)
		{
			LCD_ShowString(30,150,200,16,16,"Start Transimit....");
			LCD_ShowString(30,170,200,16,16,"   %");
			printf("\r\nDMA DATA:\r\n"); 	    
		  USART_DMACmd(USART1,USART_DMAReq_Tx,ENABLE); 
			MYDMA_Enable(DMA1_Channel4); 
		    while(1)
		    {
				if(DMA_GetFlagStatus(DMA1_FLAG_TC4)!=RESET)
				{
					DMA_ClearFlag(DMA1_FLAG_TC4);
					break; 
		    }
				pro=DMA_GetCurrDataCounter(DMA1_Channel4);
				pro=1-pro/SEND_BUF_SIZE;  
				pro*=100; 
				LCD_ShowNum(30,170,pro,3,16);	  
		    }			    
			LCD_ShowNum(30,170,100,3,16);
			LCD_ShowString(30,150,200,16,16,"Transimit Finished!");
		}
		i++;
		delay_ms(10);
		if(i==20)
		{
			LED0=!LED0;
			i=0;
		}		   
	}
}