#include "reg51.h"
#include <stdio.h>
#define uchar unsigned char
#define uint unsigned int


void Timer0(void) interrupt 1
{
	TH0=0x0c; // 定時4ms。（2000H-N）*12/14.7456us=4ms    N=CCDH
	TL0=0xcd;
	KEYZONG = P0&0x07;
	if(KEYCOUNT == 0) OLDKEY=KEYZONG;
	if(KEYZONG == 0x06||KEYZONG == 0x05||KEYZONG == 0X03)
	{
		if(KEYCOUNT<1250)
		{
			if(OLDKEY == KEYZONG)KEYCOUNT++;
			else KEYCOUNT = 0;
		}
	}
	else	
	{
		if(OLDKEY == 0X03)
		{
			if(KEYCOUNT<16){KEYCOUNT=0;OLDKEY=0;}
		}
		else{KEYCOUNT=0;OLDKEY=0;}
	}	
}

void main()
{
}
/*
說明 P0^1 P0^2 P0^3 三個端口分別有三個開關
通過檢測KEYCOUNT的值就可以知道分別按了那一個按鍵或者哪幾個按鍵
*/