kbd_drv.c

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/*C**************************************************************************
* NAME:         kbd_drv.c
*----------------------------------------------------------------------------
* Copyright (c) 2006 Atmel.
*----------------------------------------------------------------------------
* RELEASE:      C51 Sample      
* REVISION:     1.00     
*----------------------------------------------------------------------------
*
*****************************************************************************/
#include "system\reg51.h"
#include "system\compiler.h"
#include "system\config.h"
#include "driver\kbd_drv.h"                      /* scheduler definition */

/*F**************************************************************************
* NAME: kbd_init
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE: 
*   Keyboard initialisation function
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
* ram/xram:
* cycle:
* stack: 
* code:
*****************************************************************************/
void kbd_init (void)
{
	P1 = P1|0x1f;
}

/*F**************************************************************************
* NAME: kbd_decode
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*   Decoded key pressed
*----------------------------------------------------------------------------
* PURPOSE: 
*   Decode the key that generated an IT
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS:
* ram/xram:
* cycle:
* stack: 
* code:
*****************************************************************************/
/*读键盘键值程序段*/
Byte kbd_decode (void)
{
	Byte key=0;
	
	key = P1&0x1f;
	if (key != 0x1f) { key_flag = High; return(key);}
	else{
		P1_0 = Low;
		key = P1&0x1e;
		if (key != 0x1e) { key_flag = High; return(key);}
		else{
			P1_0 = High;
			P1_1 = Low;
			key = P1&0x1d;
			if (key != 0x1d) { key_flag = High; return(key);}
			else{
				P1_1 = High;
				P1_2 = Low;
				key = P1&0x1b;
				if (key != 0x1b) { key_flag = High; return(key);}
				else{
					P1_2 = High;
					P1_3 = Low;
					key = P1&0x17;
					if (key != 0x17) { key_flag = High; return(key);}
					else{
						 P1_3 = High;
						 key_flag = Low; /* Have not key process */
						 return(0x00);
					}
				}
			}
		}
	}
}