dac.c

uC/OS-II在EP7312微处理器的移植源程序

/******************************************************************************
 * $Id: dac.c,v 1.3 2005/01/10
 *
 * dac.c : dac driver and sine wave function
 *
 * Copyright (C) 2005 ayf ([e-mail])
 *******************************************************************************/

#include "dac.h"
#include <math.h>

unsigned int sine[120];
unsigned int square[120];
/* DA init */
void dac_init(void)
{

}

/*timer 1 init*/
void timer1_init(void){
	INTMR1 &= 0xfffffeff;
	SYSCON1 &=0xffffffef;
	SYSCON1 |=0x00000020;

}

/*
 * FUN:    delay five*usnum us where msnum is specified by the input parameter
 * PARA:   msnum - the number of five us you want to delay
 * Return: 
 */
void delay(int usnum){
	int i;
	TC1EOI = 0x0000;
	for(i=0;i<usnum;i++){
		TC1DATA = 0x0;
		while(!(INTSR1 & 0x00000100));
		TC1EOI = 0x0000;
	}	
	return;
}


/*
 * FUN:    generate forty sample point of sine wave:A*sin(2*pi*freq*t)+2.5
 * Para:   range - the amplier of the sine wave,should between 0 and 2.5
 * 	   freq - the phase cycle is 1/freq s, max:3k
 * Return: the time between plotting two points
 */
unsigned short generate_sine(double range,double freq){
	
	int i = 0;
	unsigned short dly;
	for(i=0;i<40;i++)
		sine[i] = range*0xfff*(sin(2*pi*i/40)+1)/5;
	dly = (1000000/(freq*40)-10)/5+1;
	return dly;
}

/* 
 * FUN:	   generate forty sample point of square wave
 * Para:   range - 0-5v
 * 	   freq  - max 3k
 * Return: the time between plotting two points
 */
unsigned short generate_square(double range,double freq){
	int i = 0;
	unsigned int tmp;
	unsigned short dly;
	tmp = range*0xfff/5;
	for(i=0;i<20;i++)
		square[i] = tmp;
	tmp = 0;
	for(i=20;i<39;i++)
		square[i] = tmp;
	dly = (1000000/(freq*40)-10)/5+1;
	return dly;
}

/*plot square wave*/
void plot_square(unsigned short dly_num){
	int i;
	for(i=0;i<40;i++){
		DAC_ADDR = square[i];
		delay(dly_num);
	}
}
	
/*plot sine wave*/
void plot_sin(unsigned short dly_num){
	int i,j;
	for (i=0;i<40;++i ) {
		DAC_ADDR = sine[i];
		delay(dly_num);
	}

	return;
}