#include<reg52.h>
#define KeyPort P2
#define uchar unsigned char
#define uint unsigned int

/*----------11.0592M 延時1ms---------*/
void delayms(int k)
{
	int i,j;
	for(i=0;i<k;i++)
		for(j=0;j<=112;j++);
}

uchar key_scan()
{
	/*uchar key;*/
	uchar temp;
	KeyPort=0xf0;
	if(KeyPort!=0xf0)
	{
		temp=KeyPort;
		KeyPort=0x0f;
		switch(KeyPort|temp)
		{
			case 0xee:return 1;
			case 0xde:return 2;
			case 0xbe:return 3;
			case 0x7e:return 4;
			case 0xed:return 5;
			case 0xdd:return 6;
			case 0xbd:return 7;
			case 0x7d:return 8;
			case 0xeb:return 9;
			case 0xdb:return 10;
			case 0xbb:return 11;
			case 0x7b:return 12;
			case 0xe7:return 13;
			case 0xd7:return 14;
			case 0xb7:return 15;
			case 0x77:return 16;
		}
	}
	else return 0;
}