/*
 * LED.c
 *    A program that turns on all LEDs, waits for a while, then turns
 *	  them all off.
 *
 * Author: C.Schramm
 * Date: February 10, 2006
 */

#define _IO_BASE        0
#define _ADDR(off)      (unsigned char volatile *)(_IO_BASE + off)
#define _P(off)         *(unsigned char volatile *)(_IO_BASE + off)
#define PORTK    _P(0x32)
#define DDRK     _P(0x33)

void delay(void);

void main(void)
{
 	 // Setup PortK with Bits 0..3 as output pins (1=output)
	 // DO NOT CHANGE
	 DDRK |= 0x0F;
	 // Turn on all four LEDs
	 PORTK = 0b00001111;
	 // Delay for a while, so that users can see the lights on
	 delay();
	 
	 // Turn on a single light of your choice.
	 // INITIALLY: Leave as is, and see which colour corresponds to Port K, Bit 0
	 // THEN: Change the value to turn on any LED(s) of your choice.
	 PORTK = 0b00000001;
	 delay();
	 
	 // Turn off all four LEDs
	 PORTK = 0b00000000;
}

/* delay
 *   Does idle work for a period of time, keeping the CPU busy
 *   but doing nothing useful
 */
void delay(void)
{
	int x;
	int y;
	int dummy = 1000;
	for(y=0; y<0x1FF; y++)
	{
	 for(x=0; x<0x3FF; x++)
	 {
		dummy = dummy + 0;
		dummy = dummy * 1;
		dummy = dummy / 1;
	 }
	}
}