#define  IVEC *((unsigned char *)0x3B) 
#define  CRG_INIT *((unsigned char *)0x38)
#define  CRG_FLAG *((unsigned char *)0x37)

#define IVEC_ADDR 0x3ff0
typedef void (*void_void_fp)(void);

void init_crg(void (*fp)(void)) {
	// sätt avbrottsperiod
	IVEC = 0x10;
	
	// Aktivera CRG
	CRG_INIT = 0x80;
	
	// Initiera avbrottsvektorn
	*((void_void_fp *)IVEC_ADDR) = fp; 
}

void kvittera_crg(void)
{
	CRG_FLAG |= 0x80;
}