4

4个io口控制矩阵键盘

#include<reg51.h>
#include<intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit bit3=P0^3;
uchar key;
void delay(unsigned int x)
{
	int j,i;
	for(i=x;i>0;i--)
		for(j=110;j>0;j--);
}
uchar code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
void main()
{
	EA=1;
	EX1=1;
	IT1=1;
   while(1)
   {
   }
}
void time0() interrupt 2
{
	   		switch(P0&0x0f)
			{
				case 15:
				key=15;break;
				case 14:
				key=14;break;
				case 13:
				key=13;break;
				case 12:
				key=12;break;
				case 11:
				key=11;break;
				case 10:
				key=10;break;
				case 9:
				key=9;break;
				case 8:
				key=8;break;
				case 7:
				key=7;break;
				case 6:
				key=6;break;
				case 5:
				key=5;break;
				case 4:
				key=4;break;
				case 3:
				key=3;break;
				case 2:
				key=2;break;
				case 1:
				key=1;break;
				case 0:
				key=0;break;
			}
	   	P0=key<<4;
		P0|=0x0f;
}