How to use Timer0 on ATMEGA128?

[bianchi77]

Guys,

Does anyone of you have experience on how to init timer0 on ATMEGA128 ?
Any shares or links will be appreciated,

Thanks

 

[jayanth.devarayanadurga]

ATMega128, 8 MHz Fosc, Timer0 10 ms interrupt, mikroC Code.

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Code C - [expand]
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//Timer0 Prescaler = 1024; Preload = 78; Actual Interrupt Time = 9.984 ms
 
//Place/Copy this part in declaration section
void InitTimer0(){
  SREG_I_bit = 1; 
  OCR0 = 78; 
  TCCR0 = 0x28;
  TCCR0 |= 0x05;
  OCIE0_bit = 1; 
}
 
void Timer0Overflow_ISR() org IVT_ADDR_TIMER0_COMP {
  //Enter your code here 
}

---

 

[bianchi77]

ATMega128, 8 MHz Fosc, Timer0 10 ms interrupt, mikroC Code.

---

Code C - [expand]
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//Timer0 Prescaler = 1024; Preload = 78; Actual Interrupt Time = 9.984 ms
 
//Place/Copy this part in declaration section
void InitTimer0(){
  SREG_I_bit = 1; 
  OCR0 = 78; 
  TCCR0 = 0x28;
  TCCR0 |= 0x05;
  OCIE0_bit = 1; 
}
 
void Timer0Overflow_ISR() org IVT_ADDR_TIMER0_COMP {
  //Enter your code here 
}

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Thank you my friend

- - - Updated - - -

How can I init it on AVR Studio ?

 

[jayanth.devarayanadurga]

These might help you.

http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=31104
http://www.avrfreaks.net/index.php?name=PNphpBB2&file=printview&t=128608&start=0
**broken link removed**

 

[bianchi77]

I created :

/*
 * Timer_simple_v1.0
 *
 * Created: 29/05/2013 11:52:36 AM
 *  Author: Antonius
 */ 
 #include <avr/io.h>
 #define LEDOFF  PORTA |= (1<<1)
 #define LEDON   PORTA &= ~(1<<1)


void init_Ex1(void)
{
	TCCR0 = (1<<CS02)|(1<<CS00); //Timer clock =
	//system clock /
	//1024
	TIFR = 1<<TOV0; //Clear TOV0 / clear
	//pending interrupts
	TIMSK = 1<<TOIE0; //Enable Timer0
	//Overflow Interrupt
	DDRC = 0xFF; //Set Port B as
	//output
}

ISR(TIM0_OVF_vect)
{
		// Add code here to derive other timebases
		PORTC = ~PORTC;
	
}

 
int main (void)
{
       init_Ex1();
	  
}

How can I call it on main() ?

thanks

- - - Updated - - -

Am I writing it correctly ? or do I miss something here ?

/*
 * Timer_simple_v1.0
 *
 * Created: 29/05/2013 11:52:36 AM
 *  Author: Antonius
 */ 
 #include <avr/io.h>



void init_Ex1(void)
{
	TCCR0 = (1<<CS02)|(1<<CS00); //Timer clock =
	//system clock /
	//1024
	TIFR = 1<<TOV0; //Clear TOV0 / clear
	//pending interrupts
	TIMSK = 1<<TOIE0; //Enable Timer0
	//Overflow Interrupt
	DDRC = 0xFF; //Set Port B as
	//output
}

ISR(TIM0_OVF_vect)
{
		// Add code here to derive other timebases
		PORTC = ~PORTC;
	
}

 
int main (void)
{
       DDRC = 0xFF;
	   PORTC = 0xFF;
	   init_Ex1();
	   ISR();
	  
}

 

[jayanth.devarayanadurga]

You have to call the timer initialization or start code once in the main(). If calling from inside while(1) loop then make sure you just call it once.

 

[Mindaugasu]

Try looking at following tutorial: http://www.embedds.com/8-bit-timercounter0-operation-modes-part1/
It is based on Atmega328, but initialization and modes are pretty same.