#include <avr/io.h>
#include <stdlib.h>
#include <util/delay.h>
#include "uart.h"

void pause(void);
void init(void);
void canreg_write(unsigned char adresse, unsigned char daten);
unsigned char canreg_read(unsigned char adresse);


void pause(void)
{

asm volatile ("nop");


} 



void can_init(void)
{
DDRA = 0xDF;
DDRC = 0xFF;



PORTA = 0x3C; /* ~INT=1 ~RST=1 ~WR=1 ~RD=1 ~CS=0 ALE=0 */
PORTA &= ~(1<<4);
PORTA |= (1<<4);
}



void canreg_write(unsigned char adresse, unsigned char daten)
{
 
PORTA |= (1<<0); // ALE Setzen
pause();
PORTC = adresse;
pause();
PORTA &= ~(1<<0); // ALE rücksetzen         
pause();     
PORTA &= ~(1<<3); // ~WR rücksetzen
pause(); 
 
PORTC = daten;     
pause();


PORTA |= (1<<3); // ~WR setzen
//PORTA |= (1<<0); // ALE Setzen
         
                                
}


unsigned char canreg_read(unsigned char adresse)
{
unsigned char daten = 0;
PORTA |= (1<<0); // ALE Setzen
pause();
PORTC = adresse;
PORTA &= ~(1<<0); // ALE rücksetzen  
pause();

DDRC = 0x00; 
PORTA &= ~(1<<2); // ~RD rücksetzen         
pause();      
daten = PORTC;   
PORTA |= (1<<2); // ~RD setzen
DDRC = 0xFF;  
return daten;      
}

 



int main(void)
{
    
	//USART initialisieren
	DDRD = 0x43;
	UCSRC &= ~(1<<UMSEL);
	USART_Init(51);
	
	//SJA1000 initialisieren
	can_init();
	unsigned char test;
	//canreg_write(0,0b00011110);
	canreg_write(0x01,0b00011111);
	test = canreg_read(0b00000010);
	USART_Transmit(test);
	
	
	while(1){
	
	USART_Transmit(test);
	
	PORTD= 0xff;
	_delay_ms(100);
	PORTD = 0x00;
	_delay_ms(100);
	
	
	}

}