key.c

来自「开发板外设接口实验（1～7）」· C语言 代码 · 共 61 行

/*
 *	int0.c   -  int0 api & driver 
 *	
 *	Author: 	li ming <[e-mail]>
 *	Date:		2008-4-16
 *	Copyleft:	http://www.lumit.org
 */
 
#include "key.h"
/*  
; hardware connection
; PIO8	(gpio)
; 1  	(int0)
; so output value = 0x00000100 = (0b0000 0000  0000 0000  0000 0001  0000 0000)
*/

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

/* set int0 related gpio */
int key_init(void)
{
	// External interrupt 0 source number is 0
	// set gpio's direction: set IOPMOD register mode bit to 0 = input
	IOPMOD = IOPMOD & (~0x00000100);
	
	return 0;
}

int key_is_down(void)
{ 
	if(IOPDATA & (1 << 8))
		return 1;	
	
	return 0;
} 

int key_is_up(void)
{ 
	if(IOPDATA & (1 << 8))
		return 0;	
	
	return 1;
} 


int status = 0;
	 
int key_test(void)
{
	key_init();
	while(1)
	{
		status = key_is_up();
		status = key_is_down();
		
	}	
	return status;
}