Hex Number Multiplication

Hex Number Multiplication

#include <Arduino.h>
byte x=0;
char lupTable[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
char display[]={B111110,B111101,B111011,B110111};
int x1,x2,z1,z2,z3,z4,y,y1,y2,y3,y4;
int shift[]={12,8,4,0};
int digit[4];
int ccCode[4];
void setup()
{
DDRB=B111111;
DDRD=0xff;
x1=0x24;
x2=0x56;
y=x1*x2;
for (int i=0;i<=3;i++)
   {
       digit[i]=y>>shift[i];
       digit[i]=digit[i]&0x000f;
       ccCode[i]=lupTable[digit[i]];
   }

}

void loop()
{
    PORTB= display[x];
    PORTD= ccCode[x];
    delay(2);
    x++;
    if (x>3) {x=0;}
}