mx21_dma.c

MX21_InitCodeLib.rar freescale mx21系列ARM芯片9328的WINCE5.0下初始化代码

/**********************************************************************
*
*         (C) COPYRIGHT 2004 FREESCALE, INC.
*         ALL RIGHTS RESERVED
*
*
*     Group/Division:  WMSG/MMDO
*
*     Description:
*
*     Related Specifications:
*
*     Errata:
*
*     File Name:        MX21_DMA.c
*     Revision Number:  0.1
*     Author(s):        E Kroitor
*     Date created:     30 September 2004
*     Revision History:
*        Date      Rev     Description
*        ----      ---     -----------
*        30Sept04  0.1     First draft
*
**********************************************************************/

#include "MX21_DMA.h"

    uint32_t gFailCount, ccnr0, i, pattern;	
	p_uint32_t memSrc, ps, memDst;

void 
dmaDemo(void)
{

// define memory source, where dat is copied from
	memSrc   = (p_uint32_t)(SOURCE_ADDRESS);
			
// define memory destination, where the memory is being copied to	
	memDst   = (p_uint32_t)(DESTINATION_ADDRESS);	
										

/*************************************************
*** DMA Transfer 
*************************************************/

	dmaSetUp(memSrc, memDst, NUMBER_OF_BYTES, DMA_BURST_LENGTH); // call DMA setup function
	
	fillMem(Enable); // call the pattern generation and memory fill function

	enableDmaTransfer(Enable); // call the DMA transfer function

} /* end of main */


void 
dmaSetUp(p_uint32_t src, p_uint32_t dest, int num_bytes, int burst_length)
{
	
	printf("\n DMA transfer program from memory to memory.\n");
	PRINTF(" Number of bytes to transfer: %d\n", NUMBER_OF_BYTES);
	

	// reset the DMA
	DMAC_DCR.bits.DRST = Enable; 
	
	// PCCR0 DMA Clocks Enable

    PLLCLK_PCCR0.bits.HCLK_DMA_EN = Enable;
    PLLCLK_PCCR0.bits.DMA_EN = Enable; 

	// set up DMA control registers 
	PRINTF("Setting up DMA registers \n");
	
	// enable the DMA
	DMAC_DCR.bits.DEN = Enable;
	
	// DMA source address 
	DMAC_SAR0.all = (uint32_t)src;

	// DMA destination address 
	DMAC_DAR0.all = (uint32_t)dest;
	
	// set up the channel count register with 
	DMAC_CNTR0.all = num_bytes;
	
	// number of bytes to transfer
	DMAC_BLR0.all = burst_length;
	
	// set up the Channel Control Register
	// DMOD and SMOD are linear, MDIR is incrementing, DSIZ is word
	// SSIZ is word, REN = initiate DMA transfer when CEN = 1
	
    DMAC_CCR0.all = 0x00000000;
    
} /* End of dmaSetUp function */
			

void
fillMem(uint32_t EN)
{
		
	// fill memory source
		for( ps = memSrc, i = 0, pattern = 0; i < SDRAM_TEST_LENGTH ; i+= 4, ps += 1 ) 
	    { 
			 
			*ps = pattern; 
			pattern += 0x11112222; 
	    } 

     gFailCount = 0;
	  
	 // verify values were programmed
	    for( ps = memSrc, i = 0, pattern = 0; i < SDRAM_TEST_LENGTH; i+= 4, ps += 1 ) 
	    {
	   		
	    	if (*ps != pattern)
	    	{
	    		gFailCount++;
	       	}
	    
	    	pattern += 0x11112222; 
	    }
	   
	   	if (gFailCount != 0)
	   	{
	   		// the data in source memory does NOT match the data that was programmed there
	   		PRINTF(" **FAIL: Memory was NOT programmed correctly\n"); 
	   	}
	   	
	   	else
	   	{
	   		// the data in source memory matches the data that was programmed there
	   		PRINTF(" Memory was programmed correctly.\n");
	   	}
} /* End of fillMem function */

void
enableDmaTransfer(uint32_t EN)
{
		
	gFailCount = 0;
	
	// enable interrupts by disabling masking
	DMAC_DIMR.bits.CH15_CH0 = 0xFFFF; // ~!@ Check on this then delete

	// enable DMA channel
	DMAC_CCR0.bits.CEN = EN;
	
	// wait until transfer complete
	while (DMAC_DISR.bits.CH15_CH0 = 0);
		

	printf(" DMA transfer complete \n");
	
	// calculate number of bytes transferred by reading CCNR0 register
	// then print result on console
	ccnr0 = DMAC_CCNR0.all;
	printf(" Bytes transferred = %d\n", ccnr0);
	gFailCount = 0;	
	
	// verify that data was transferred correctly
    for (ps = memDst, i = 0, pattern = 0; i < SDRAM_TEST_LENGTH; i+= 4, ps += 1 ) 
   	{
   		if (*ps != pattern)
    		{
    			gFailCount++;
    		
    			PRINTF(" Address = %x\n", ps); 	// address of memory location that failed
       		}
       	pattern += 0x11112222;
    }
   
   	if (gFailCount != 0)
   	{
   		// dma transfer issue since data in destination memory does not match data in source memory
   		printf(" **FAIL: Memory didn't transfer correctly, DMA transfer failed\n");
   		printf (" gFailCount = %d\n", gFailCount);
   	}

	else
	{
		// dma transfer took place and programmed correctly in destination address
		printf(" Memory was transfered correctly via DMA.\n");
	}


} /* End of enableDmaTransfer function */