Addition to l3cube

gistfile1.txt

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

#define CPU_PRESCALE(n)	(CLKPR = 0x80, CLKPR = (n))

#define FPS 1;

volatile int frame = 0;
uint8_t cube[4][4];
int mode = 0;

int lvl_arr[4] = {0b1000,0b0100,0b0010,0b0001};
int frame_arr[5][4] = {{0b1001,0b1001,0b1111,0b1001}, {0b1111,0b1000,0b1110,0b1111}, {0b1111,0b1000,0b1000,0b1000}, {0b1111,0b1000,0b1000,0b1000},{0b1111,0b1001,0b1001,0b1111}};
int main(void)
{
    int lvl;
	// set for 16 MHz clock, and make sure the LED is off
	CPU_PRESCALE(0);
	// set b & d ports as output
	DDRD = 255;
	DDRC = 255;
	DDRB = 255;
	//setup the interrupt-timer
    TCCR1B |= (1 << WGM12); // Configure timer 1 for CTC mode 
    TIMSK1 |= (1 << OCIE1A); // Enable CTC interrupt 
    sei(); //  Enable global interrupts 
    OCR1A   = 15624/FPS; // Set CTC compare value to 1Hz at 1MHz AVR clock, with a prescaler of 64 
    TCCR1B |= ((1 << CS10) | (1 << CS12)); // Start timer at Fcpu/64 

    while (1) 
    {
        for(lvl=0;lvl<=3;lvl++)
	    {
	        PORTB = lvl_arr[lvl];
	        
	        switch(mode)
            {
	        case 0:
	             PORTD = frame_arr[frame][lvl] + 16*frame_arr[frame][lvl];
	             PORTC = frame_arr[frame][lvl] + 16*frame_arr[frame][lvl];
	            _delay_ms(2);
	         break;
	         
	         default: 
	         break;	           
	         } 
	    } 
    }
}

ISR(TIMER1_COMPA_vect) 
{ 
   frame++;
   if (frame > 4) 
   { 
      frame=0;
   }
}