dma_config.c

基于BF533的视频采集及显示

/******************************************************************************/
//
// Name: 	BF533 DMA Setup
//
/******************************************************************************

File Name:	DMA_Config.c

Special Connections:  None

Purpose:		The file sets up the DMA transfer
								
*********************************************************************************/

#include <cdefBF533.h>
#include "DMA_Config.h"

void Init_DMA(void)
{
	unsigned char i=0;
		
	// DMA  Descriptor  Array  Mode Start Address 
    unsigned short *pDMA_DAMSA;
    pDMA_DAMSA= (unsigned short *)0x00AA0000;
    //DMA  Descriptor  Array write	
	for(i=0 ;i<25 ;i++)
	{
		// DMA Channel 0 Next Descriptor Pointer Register
		pDMA_DAMSA[0+i*8] = (unsigned short)((i + 1) * 16);
		
		//Target address of the DMA
		//pDMA_DAMSA[1+i*8] = (unsigned short)((i * 414720)&0xFFFF);
		//pDMA_DAMSA[2+i*8] = (unsigned short)(((i * 414720)&0xFFFF0000)>>16);
		pDMA_DAMSA[1+i*8] = (unsigned short)((i * 414720)&0xFFFF);
		pDMA_DAMSA[2+i*8] = (unsigned short)(((i * 414720)&0xFFFF0000)>>16);
		
		//DMA Config: Enable DMA | Memory write DMA | Two Dim| Discard DMA FIFO before start | enable assertation of interrupt | NDSIZE for stop mode 
		//pDMA_DAMSA[3+i*7] = DMAEN | WNR | WDSIZE_32 | DMA2D | RESTART | DI_SEL | DI_EN | 0x0800 | 0xE000 ;
		pDMA_DAMSA[3+i*8] = DMAEN | WNR | WDSIZE_16 | DMA2D | RESTART | DI_SEL | DI_EN | 0x0800 | 0x6000 ;
		
		//RAM_Length 32bit transfers will be executed
		pDMA_DAMSA[4+i*8] = RAMCOW_Length;
		
		//The modifier is set to 4 because of the 32bit transfers
		pDMA_DAMSA[5+i*8] = 0x2;
		
		//RAM_Length 32bit transfers will be executed
		pDMA_DAMSA[6+i*8] = RAMROW_Length;
		
		//The modifier is set to 4 because of the 32bit transfers
		pDMA_DAMSA[7+i*8] = 0x2;	
	}
		
	// DMA Channel 0 (24) Descriptor Pointer Register	
//	pDMA_DAMSA[0+24*8] = (unsigned short)0x0;
	
	/*------------------------------------------------*/
	
	//Target address of the DMA
	*pDMA0_START_ADDR = 0x0;

	//RAM_Length 32bit transfers will be executed
	*pDMA0_X_COUNT = RAMCOW_Length;

	//The modifier is set to 4 because of the 32bit transfers
	*pDMA0_X_MODIFY = 0x2;	
														
	//RAM_Length 32bit transfers will be executed
	*pDMA0_Y_COUNT = RAMROW_Length;

	//The modifier is set to 4 because of the 32bit transfers
	*pDMA0_Y_MODIFY = 0x2;
	
	// DMA Channel 0 Next Descriptor Pointer Register	
	*pDMA0_NEXT_DESC_PTR = (unsigned short *)0x00AA0000;
	
		
	//PPI Peripheral is used
	*pDMA0_PERIPHERAL_MAP = 0x0;
	
	//DMA Config: Enable DMA | Memory write DMA | Two Dim| Discard DMA FIFO before start | enable assertation of interrupt | NDSIZE for stop mode 
	//*pDMA0_CONFIG = DMAEN | WNR | WDSIZE_32 | DMA2D | RESTART |  DI_SEL | DI_EN |0x0800 |0xE000; 
	*pDMA0_CONFIG = DMAEN | WNR | WDSIZE_16 | DMA2D | RESTART | DI_SEL | DI_EN |0x0800 |0x6000; 
	    

}