//-------------------------------------------------------------
#include <avr/io.h>
#include <avr/cpufunc.h>
#include <avr/wdt.h>
#include <inttypes.h>
#include <util/atomic.h>
#include "pin_macros.h"

#define TP3_ON            VPORT1_OUT |= PIN3_bm        //
#define TP3_OFF            VPORT1_OUT &= ~PIN3_bm        //

//-----------------    THE MAIN --------------------------------------
int main (void)
    {
    cli();
    // SYSTEM_CLK = 8 MHz:
    OSC.CTRL = 0x61;            // RC8MEN & RC2MEN
    while(!(OSC.STATUS & OSC_RC8MRDY_bm));
    CPU_CCP = CCP_IOREG_gc;        // protected by the configuration change protection mechanism
    CLK.CTRL = 0x05;            // 101- RC8MHZ (8MHz internal oscillator)
    // PORTC:
    PORTC.DIR = 0x08;            // TP3
    PORTC.OUT = 0x00;        
    // PORTD:
    PORTD.DIR = 0x10;            // pin4
    PORTD.OUT = 0x00;        
    PORTCFG.CLKOUT = 0x82;        // Clock output on PORTD pin4
    // WDT:
    CPU_CCP = CCP_IOREG_gc;        // protected by the configuration change protection mechanism
    WDT.CTRL = 0x27;            // 4.0s
    //
    sei();
    //
    while(1)        
        {
        TP3_ON;
        wdt_reset();
        TP3_OFF;
        wdt_reset();
        }
    }

void write_CCP_gurad(void* addr,BYTE value)
    {
      asm ("MOVW    R31:R30, R17:R16\n");
      asm ("LDI     R19, 216\n");
      asm ("OUT     0x34, R19\n");
      asm ("ST      Z, R18\n");
    }

write_CCP_gurad((void*)&CLK.CTRL,0x05);