What triggers a timer counter overflow interrupt?

What triggers a timer counter overflow interrupt?

The timers run parallel and independent of the CPU at a specific frequency, and interact with the CPU by issuing interrupts. Overflow interrupt is triggered whenever the timer register overflows, i.e. reaches its maximum value (in this case, 255, or, in hexadecimal, FFh).

How does timer overflow interrupt work?

This means that you can reduce the frequency of the timer. Well, when the timer counter reaches its maximum value in bit – means that if the timer is a 8-bit timer, it can reaches maximum 255 – the timer go back to zero. At this specific moment, the timer overflow interrupt occur.

When does an AVR microcontroller fire an interrupt?

This interrupt can be fired whenever certain conditions are met. Now whenever an interrupt is fired, the AVR stops and saves its execution of the main routine, attends to the interrupt call (by executing a special routine, called the Interrupt Service Routine, ISR) and once it is done with it, returns to the main routine and continues executing it.

How are interrupts used in all microcontrollers?

University of Tehran 9 Interrupts • Interrupting mechanism in all microprocessors and microcontrollers is almost the same: – Define the set of devices and events that can generate an interrupt – Write a function for each interrupt that will be executed when the corresponding interrupt is activated

What does the timsk Register do in atmega16-avr?

TIMSK or Timer/Counter Interrupt Mask Register is a control register used to mask or unmask the timer interrupts. The bit 0 of TIMSK Register controls the overflow interrupt of Timer 0. Setting this bit to ‘1’ enables the overflow interrupt of timer 0.

What happens when timer overflows on AVR Flasher?

Since the required delay (50ms) is greater than the maximum possible delay: 4,096ms = 1000ms / 62500Hz * 256, obviously the timer will overflow. And whenever the timer overflows, an interrupt is fired.