dma.c

NXP产品LPC23XX的开发板的源文件

/*****************************************************************************
 *   dma.c:  DMA module file for NXP LPC23xx/24xx Family Microprocessors
 *
 *   Copyright(C) 2006, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2006.07.20  ver 1.00    Prelimnary version, first Release
 *
******************************************************************************/
#include "LPC23xx.h"                        /* LPC23xx/24xx definitions */
#include "type.h"
#include "irq.h"
#include "dma.h"

volatile DWORD DMATCCount = 0;
volatile DWORD DMAErrCount = 0;

/******************************************************************************
** Function name:		DMAHandler
**
** Descriptions:		DMA interrupt handler
**
** parameters:			None
** Returned value:		None
** 
******************************************************************************/
void DMAHandler (void) __irq 
{
    DWORD regVal;

    IENABLE;				/* handles nested interrupt */
	regVal = GPDMA_INT_TCSTAT;
	if ( regVal )
	{
		DMATCCount++;
		GPDMA_INT_TCCLR |= regVal;
	} 

	regVal = GPDMA_INT_ERR_STAT;
	if ( regVal )
	{
		DMAErrCount++;
		GPDMA_INT_ERR_CLR |= regVal;
	} 
    IDISABLE;
    VICVectAddr = 0;		/* Acknowledge Interrupt */
}

/******************************************************************************
** Function name:		DMA_Init
**
** Descriptions:		
**
** parameters:			
** Returned value:		
** 
******************************************************************************/
DWORD DMA_Init( DWORD DMAMode )
{
	/* USB RAM is used for test.
	Please note, Ethernet has its own SRAM, but GPDMA can't access
	that. GPDMA can access USB SRAM and IRAM. Ethernet DMA controller can 
	access both IRAM and Ethernet SRAM. */
	PCONP |= (1 << 29);	/* Enable GPDMA clock */

	/* clear all interrupts on channel 0 */
	GPDMA_INT_TCCLR = 0x01;
	GPDMA_INT_ERR_CLR = 0x01;
   
	if ( DMAMode == M2M )
	{
		/* Ch0 is used for M2M test, for M2P and P2M, go to peripheral directories
		where both DAM and non DMA examples are provided. */
		GPDMA_CH0_SRC = DMA_SRC;
		GPDMA_CH0_DEST = DMA_DST;
		/* Terminal Count Int enable */
		GPDMA_CH0_CTRL = ((DMA_SIZE/4) & 0x0FFF) | (0x04 << 12) | (0x04 << 15) 
			| (0x02 << 18) | (0x02 << 21) | (1 << 26) | (1 << 27) | 0x80000000;	
	}
	else
	{
		return ( FALSE );
	}
	
	GPDMA_CONFIG = 0x01;	/* Enable DMA channels, little endian */
	while ( !(GPDMA_CONFIG & 0x01) );    
		
	if ( install_irq( GPDMA_INT, (void *)DMAHandler, HIGHEST_PRIORITY ) == FALSE )
    {
		return ( FALSE );
    }
    return (TRUE);
}

/******************************************************************************
**                            End Of File
******************************************************************************/