stm32之DMA隨筆2

M(內存) TO P(外設)編程要點：
1 初始化串口
2 配置DMA初始化結構體
3 編寫主函數

主體函數main.c(頭文件省略)
 

extern const uint32_t aSRC_Const_Buffer[BUFFER_SIZE];
extern uint32_t aDST_Buffer[BUFFER_SIZE];
extern uint8_t SendBuffer[SENDBUFF_SIZE];
int main(void)
{
	USART_Config();
	USARTx_DMA_Config();
	for(i=0;i<SENDBUFF_SIZE;i++){
	
		SendBuffer[i]='P';
	}
	
	USART_DMACmd(DEBUG_USARTx,USART_DMAReq_Tx,ENABLE);
	while(1)
	{
		;
	}
}

目標函數體：bsp_dma_mtp.c

#include"bsp_dma_mtp.h" 

uint8_t SendBuffer[SENDBUFF_SIZE];



void USARTx_DMA_Config(void)
{

	 DMA_InitTypeDef DMA_InitStruct;
	 RCC_AHBPeriphClockCmd(USART_TX_DMA_CLK, ENABLE);
	 DMA_InitStruct.DMA_PeripheralBaseAddr=(uint32_t)USART_DR_ADDRESS;
	 DMA_InitStruct.DMA_MemoryBaseAddr=(uint32_t)SendBuffer;
	
	
	
	
	 DMA_InitStruct.DMA_DIR=DMA_DIR_PeripheralDST;
	
	
	DMA_InitStruct.DMA_BufferSize=SENDBUFF_SIZE;
	DMA_InitStruct.DMA_PeripheralInc=DMA_PeripheralInc_Disable;
	DMA_InitStruct.DMA_MemoryInc=DMA_MemoryInc_Enable;
	DMA_InitStruct.DMA_PeripheralDataSize=DMA_PeripheralDataSize_Byte;
	DMA_InitStruct.DMA_MemoryDataSize=DMA_MemoryDataSize_Byte;
	
	DMA_InitStruct.DMA_Mode=DMA_Mode_Normal;
	DMA_InitStruct.DMA_Priority=DMA_Priority_Medium;
	DMA_InitStruct.DMA_M2M=DMA_M2M_Disable;
	
	

	DMA_Init(USART_TX_DMA_CHANNEL,&DMA_InitStruct);
	//DMA_ClearFlag(USART_TX_DMA_FLAG_TC);
	DMA_Cmd(USART_TX_DMA_CHANNEL,ENABLE);
}

函數體頭文件：bsp_dma_mtp.h

#ifndef __BSP_DMA_MTP_H
#define __BSP_DMA_MTP_H

#include"stm32f10x.h"


#define USART_TX_DMA_CLK			RCC_AHBPeriph_DMA1
#define USART_TX_DMA_CHANNEL  DMA1_Channel4		//此處易失誤
#define USART_TX_DMA_FLAG_TC  DMA1_FLAG_TC4
#define USART_DR_ADDRESS			(USART1_BASE+0x04)	

#define SENDBUFF_SIZE					 5000

void USARTx_DMA_Config(void);


#endif /* __BSP_DMA_MTP_H*/