/**********************************************
*   File: IntKeyboard_2.C
*   Description: Int Direct Keyboard Interface Example
*   Created Date:  2007-10-01
*   Last Modified: 2007-10-01
*   Author: Jeffrey - Schicksal@126.com
*   Notes: None
**********************************************/

#include "Atmel/AT89X51.h"
volatile unsigned char Keys_Value;					// 定義鍵值變量

/**********************************************
*   Function: delay(unsigned int t)
*   Input Variables: t
*   Return Variables: None
*   Usage: Common Delay Routine, t as the delay time ticks
**********************************************/
void delay(unsigned int t)
{
		for(;t>0;t--);		// 延時循環(huán)
}

/**********************************************
*   Function: main()
*   Input Variables: None
*   Return Variables: None
*   Usage: Program Entry
*********************************************/
void main()
{
		while(1)
		{
				P0 = ~Keys_Value;					// 點亮相應的LED燈
				
				//********************主程序部分*********************//
				// Add your code here
				//********************主程序部分*********************//
				delay(100);
		}
}

/**********************************************
*   Function: Read_Keyboard
*   Input Variables: None
*   Return Variables: none
*   Usage: Interrupt Routine Read Keyboard Status
*********************************************/
void Read_Keyboard(void) interrupt IE0_VECTOR 		 //  中斷向量
{
		P2 = 0xff;									// P2口置高，準備讀取按鍵狀態(tài)
		Keys_Value = P2;							// 讀取按鍵狀態(tài)
}