#include <iom16v.h>
#include <macros.h>
#define  uchar unsigned char
#define  uint  unsigned int
#pragma data:code 
const  table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d, 0x07,
		           0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0XFF};
void delay(uint ms)
{
        uint i,j;
	for(i=0;i<ms;i++)
	   {
	   for(j=0;j<1141;j++);
       }
}
void show(uchar j,uchar k)
{
        PORTA|=BIT(3);
	PORTB=table[j];
	PORTA&=~BIT(3);
	
	PORTB=0XFF;
	PORTB&=~BIT(k);
	PORTA|=BIT(4);
	PORTA&=~BIT(4);
	delay(1);
}
uchar key_press()
{
     uchar i;
     DDRD=0XFF;
	 PORTD=0XF0;
	 
	 DDRD=0X0F;
	 
	 i=PIND;
	 if(i==0XF0)
	 {
	   DDRD=0XFF;
	   return 0;
	 }
	 else
	 {
	   DDRD=0XFF;
	   return 1;
	 }
}

uchar key_scan()
{
     uchar key,i=0X7F,j;
     delay(10);
	 if(key_press())
	 {
	    do
		{
		 i=(i<<1|i>>7);
		 PORTD=i;
		 DDRD=0X0F;
		 
		 key=PIND;
		 j=key&0XF0;
		 
	    }while(j==0XF0);
		
		while(key_press());
		switch(key)
		{
       case 0xEE:
	   		key=0x0;
			break;
	   case 0xDE:
	   		key=0x1;
			break; 
	   case 0xBE:
	   		key=0x2;
			break;
	   case 0x7E:
	   		key=0x3;
			break;
	   case 0xED:
	   		key=0x4;
			break;
	   case 0xDD:
	   		key=0x5;
			break;
	   case 0xBD:
	   		key=0x6;
			break;
	   case 0x7D:
	   		key=0x7;
			break;
	   case 0xEB:
	   		key=0x8;
			break;
	   case 0xDB:
	   		key=0x9;
			break;
	   case 0xBB:
	   		key=0xA;
			break;
	   case 0x7B:
	   		key=0xB;
			break;
	   case 0xE7:
	   		key=0xC;
			break;
	   case 0xD7:
	   		key=0xD;
			break;
	   case 0xB7:
	   		key=0xE;
			break;
	   case 0x77:
	   		key=0xF;
			break;
	   default:
	        key=16;		
		}
	 }
	 else
	 {
	    key=16;
	 }
	 return key;
}
void main()
{
     uchar l;
     DDRA|=0X18;// 0001 1000
 	 DDRB=0XFF;
	 while(1)
	 {
	   if(key_press())
	   {
	      l=key_scan();
		  show(l,0);
	   }
	 }
	 
}