dac.c

EBD7312 DAC SDT 测试程序及驱动程序

/*
 * $Id: dac.c,v 1.3 2003/08/29 09:20:32 ynding Exp $
 *
 * dac.c : dac driver
 *
 * Copyright (C) 2003 ynding ( [e-mail] )
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "dac.h"

/* waves */
static unsigned int pulse[12] = {
	0x77777777,0x77777777,0x77777777,0x77777777,0x77777777,0x77777777,
	0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000
};

static unsigned int triangle[12] = {
	0x00000000,0x15151515,0x2a2a2a2a,0x3f3f3f3f,0x54545454,0x69696969,
	0x7e7e7e7e,0x69696969,0x54545454,0x3f3f3f3f,0x2a2a2a2a,0x15151515
};

static unsigned int sine[12] = {
	0x3f3f3f3f,0x5f5f5f5f,0x76767676,0x7f7f7f7f,0x76767676,0x5f5f5f5f,
	0x3f3f3f3f,0x20202020,0x09090909,0x00000000,0x09090909,0x20202020
};

static unsigned int* wave[3] = { pulse, triangle, sine };

/* time delay */
void wait(int time)
{
	int i = 0;
	int j = 0;

	for ( i=0;i<time;++i ){
		for ( j=0;j<1000;++j )
			;
	}

	return;
}

/* DA conversion */
void dac( unsigned int data )
{
	MEMCFG2 |= 0x00000012;

	DAC_ADDR = data;

	return;	
}

/* generate wave */
void generate_wave(int wavetype, int interval)
{
	int i = 0;

	for ( i=0;i<12;++i ) {
		DAC_ADDR = wave[wavetype][i];
		wait(interval);
	}

	return;
}