ATMega16 Timer/Counter0 Compare Output Mode

 

Introduction

Compare Output Mode of Timer/Counter0 is also calls waveform generation. It’s different from normal mode, CTC, and PWM mode.

 

We can use this mode to create a waveform in a form of toggling , set, and clear OC0 pin on compare match. However it’s just like a normal timer mode but it’s additionally able to trigger an output at OC0 pin. Toggling OC0 at compare match is just a square wave output with a programmable frequency.

Programming

Waveform generation mode is selected by Compare Output Mode bit for non-PWM mode of the Timer/Counter Control Register (TCCR0).

Compare Output Mode bit of TCCR0

Within this example I program the ATMega16 to toggle OC0 on compare match. Crystal frequency of microcontroller is 16MHz with its clock select bit of 1:1024. Hence the toggling output occurs for every,

Equation to find the toggling time of waveform generation

 We can find the frequency of square wave output as,

Equation to find waveform generation frequency

 Finally the microcontroller program coded to toggle OC0 output with a frequency of 30.52Hz.

/*
 * timerCounter0_CompareOutputMode.c
 *
 * Created: 12/14/2020 10:36:58 PM
 * Author : admin
 */
 
#include <avr/io.h>
 
int main(void)
{
    /*CTC Mode, Toggle OC0, 1:1024 Prescaler*/
    TCCR0=(1<<COM00)|(1<<CS02)|(1<<CS00);
    /*OC0 Output*/
    DDRB=(1<<3);
    while (1)
    {
    }
}

Let see the hardware simulation in Proteus.

Proteus simulation for waveform generation

Click here to download zip file for this working example.