#include<reg52.h>
#include<stdio.h>
#define uchar unsigned char
#define KEYPORT   P2

 unsigned char keyscan(void)
  {
    uchar scancode,tmpcode;
	KEYPORT=0xf0;		                  //發全1行掃描碼
	  if((KEYPORT&0xf0)!=0xf0)					  //若有鍵按下
	     {
	        uchar i;
	            for(i=10000;i>0;i++);				  //延時去抖動

	            if((KEYPORT&0xf0)!=0xf0)			  //延時后再判斷一次，去除抖動影響
	            {
		          scancode=0xfe;

	 	              while((scancode&0x10)!=0)	    //逐行掃描
	                 	{
		                  KEYPORT=scancode;				  //輸出行掃描碼

		                     if((KEYPORT&0xf0)!=0xf0)        //本行有鍵按下
		                        {
		                           tmpcode =(KEYPORT&0xf0)|0x0f;  /* 返回特征字節碼，為1的位即對應于行和列*/
			                       return((~scancode)+(~tmpcode));
		                         }
		                     else scancode =(scancode<<1)|0x01;  //行掃描碼左移一位
		                  }

	              }

	       }

	    else return(0);
	}

void convert(void)
 {
   uchar key;
					  
   key=keyscan();

	   switch(key)
	   {
	      case 0x11: keycode=1; break;
          case 0x21: keycode=2; break;
	      case 0x41: keycode=3; break;
	      case 0x81: INC_1K=1; break;
	      case 0x12: keycode=4; break;
	      case 0x22: keycode=5; break;
	      case 0x42: keycode=6; break;
	      case 0x82: INC_100HZ=1; break;
	      case 0x14: keycode=7; break;
	      case 0x24: keycode=8; break;
	      case 0x44: keycode=9; break;
	      case 0x84: F_P=~F_P; break;
	      case 0x18: CANCEL=1; break;
	      case 0x28: keycode=0; break;
	      case 0x48: CONFIRM=1; break;
	      case 0x88: INC_1M=1; break;
	      default:   break;
	   }
	  

	   

  }