beep.c

开发板外设接口实验（1～7）

/*
 *	beep.c   -  beep api & driver 
 *	
 *	Author: 	li ming <[e-mail]>
 *	Date:		2008-4-16
 *	Copyleft:	http://www.lumit.org
 */
 
#include "beep.h"

/*  
; hardware connection
; PIO16	(gpio)
; 1  	(beep)
; so output value = 0x00010000 = (0b0000 0000  0000 0001  0000 0000  0000 0000)
*/

/* define the relative gpio register */
#define SYSCFG      0x03FF0000
#define IOPMOD		(*((volatile unsigned *)(SYSCFG+0x5000)))
#define IOPDATA		(*((volatile unsigned *)(SYSCFG+0x5008)))

/* set beep related gpio */
int beep_init(void)
{
	// set gpio's direction: set IOPMOD register mode bit to 1 = output
	IOPMOD = IOPMOD | 0x00010000;
	
	return 0;
}

int beep_on(void)
{ 
	IOPDATA |= 1 << 16;
	
	return 0;
} 

int beep_off(void)
{ 
	IOPDATA &= (~1 << 16);
	
	return 1;
} 

/* delay for about one second */
static void delay(int time)	
{
	int i, j;

	for(i = 0; i < time; i++)
		for(j = 0; j < 65536; j++)
			;
}

int beep_test(void)
{
	beep_init();
	
	while(1)
	{
		beep_on();
		delay(100);
		beep_off();
		delay(100);
	}	
	return 0;
}