#include <Mega32.h>
#include <delay.h>
#include <stdio.h>

unsigned char getmem(unsigned int addr){
	unsigned char data = 0x00;
	//delay_us(1);
	DDRA = 0x00; // set data lines to read
	//delay_us(1);
	PORTB = (unsigned char)((addr & 0xff00) >> 8);
	//PORTB.1 = 1;
	//delay_us(1);
	PORTC = (unsigned char)(addr & 0x00ff);
	//delay_us(1);
	PORTD.3 = 1; // set to read
	//delay_us(1);
	#asm("nop");
	#asm("nop");
	data = PINA;
	//delay_us(1);
	return data;
}

void setmem(unsigned int addr, unsigned char value){
	DDRA = 0xff; // set data lines to write
	//delay_us(1);
	PORTB = (unsigned char)((addr & 0xff00) >> 8);
	//PORTB.1 = 1;
	//delay_us(1);
	PORTC = (unsigned char)(addr & 0x00ff);
	//delay_us(1);
	PORTA = value;
	//delay_us(1);
	PORTD.3 = 0; // set to write
	//delay_ms(1);
	PORTD.3 = 1; // set back to read (for video)
	//delay_us(1);
	DDRA = 0x00; // set data lines to read again
	//delay_us(1);
}


void main(){
    unsigned long i = 0;
    unsigned char data;
    unsigned int num_errors = 0;
    UBRRL = 103 ; //sets UART baud rate, using a 16 MHz crystal this is 9600 baud

    DDRD = 0xff;
    DDRB = 0xff;
    DDRC = 0xff;
    PORTD.2 = 0;

    // initialize interrupts
    UCSRB = 0b00011000 ; // enables usart transmit and receive, and TXempty interrupt
    delay_ms(50);
    UDR = 'H';
    delay_ms(5);

    //while(1){
    /*for(i = 0; i < 65536; i++){
		 	setmem(i,0xff);
    } */

	for(i = 0; i < 65536; i++){
		setmem(i,(unsigned char)i);
	}

	PORTA = 0xff;

		for(i = 0; i < 65536; i++){
//	 	 	setmem(i,(unsigned char)0xff);
//		 	setmem(i,0);
		 	//delay_us(1);
		 	data = getmem(i);
		 	//data = getmem(i);
//		 	UDR = data;
//		 	delay_ms(1);
			/*UDR = data;
			delay_ms(2);*/
		 	if(data != (unsigned char)i)//(unsigned char)i)
		 	{
		 		//UDR = data;
		 		//setmem(i,0);
		 		/*while(0 != data){
		 			data = getmem(i);
		 			 UDR = data;
		 			 num_errors++;
		 		}*/
		 		num_errors++;

		 		//delay_ms(5);
 				UDR = data;
 				delay_ms(5);
			 	UDR = (unsigned char)(i>>8);
			 	delay_ms(5);
			 	UDR = (unsigned char)i;
			 	delay_ms(5);
		 	}
		 	/*else{
		 		UDR = 0;
		 	}*/
		}
		UDR = num_errors >> 8;
		delay_ms(5);
		UDR = num_errors;


		delay_ms(5);
		UDR = 0 ;
		delay_ms(5);
		UDR =0;
		delay_ms(5);
		UDR = 0;
		delay_ms(5);
		UDR = 0;
		delay_ms(5);
		UDR = 0;
		delay_ms(5);
    //}


}