mega8 MCUCSR (MCUSR for mega328) test

main.c

/*
 * resetevents.c
 *
 * Created: 2019-01-30 20:43:30
 * Author : saper
 */ 

#include <avr/io.h>
#include <inttypes.h>
//#include <avr/interrupt.h>
#include <avr/wdt.h>
#include <avr/pgmspace.h>

#include "lib/delay.h"
#include "lib/usart.h"


uint8_t reg = 0;

int main(void)
{


	reg = MCUCSR; // MCUSR for ATmega328
	// led
	PORTB |= 1<<0;
	DDRB |= 1<<0;
	// button
	DDRC &= ~(1<<5);
	PORTC |= 1<<5;

	usart_config(25, USART_TX_ENABLE | USART_RX_ENABLE , USART_MODE_8N1);//| USART_RX_INT_COMPLET
	usart_send_strP(PSTR("\r\nSystem reset...\r\nMCUCSR="));
	usart_send_hex_byte(reg);
	usart_send_char(' ');
	usart_send_bin_byte(reg);
	if ((reg & 0x01) == 0x01) {
		usart_send_strP(PSTR("\r\nCPU reset from: Power-ON\r\n"));	
	} else if ((reg & 0x02) == 0x02) {
		usart_send_strP(PSTR("\r\nCPU reset from: RESET pin\r\n"));	
	} else if ((reg & 0x04) == 0x04) {
		usart_send_strP(PSTR("\r\nCPU reset from: Brown-out (under/over voltage)\r\n"));
	} else if ((reg & 0x08) == 0x08) {
		usart_send_strP(PSTR("\r\nCPU reset from: WATCHDOG\r\n"));
	}
	// zero MCUCSR
	//MCUCSR = 0; // MCUSR for ATmega328
	// disable wdt  to let user relese button
	reg = MCUCSR;
	usart_send_strP(PSTR("\r\nMCUCSR(1)="));
	usart_send_hex_byte(reg);
	
	wdt_disable();
	while((PINC & (1<<5)) == 0) {
		delay1ms(50);
		PORTB ^= 0x01;
	}
	delay1ms(250);
	
	reg = MCUCSR;
	usart_send_strP(PSTR("\r\nMCUCSR(2)="));
	usart_send_hex_byte(reg);
	
	
	// enable WDT
	wdt_enable(WDTO_250MS);
	wdt_reset();
	
	reg = MCUCSR;
	usart_send_strP(PSTR("\r\nMCUCSR(3)="));
	usart_send_hex_byte(reg);

    while (1) 
    {
		delay1ms(100);
		PORTB ^= 0x01;

		while((PINC & (1<<5)) == 0) {
			delay1ms(20);
			PORTB ^= 0x01;
		}
		wdt_reset();	
    }
}