What is timer overflow interrupt?

What is timer overflow interrupt?

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. This means that we can do something at the frequency that we want.

How many timers is ATtiny85?

Tiny basic PWM The ATtiny85 microcontroller allows us to generate an analog output using PWM. The ATtiny85 microcontroller has two timers that can be used to generate PWM signals. The first is Timer 0, an 8-bit timer capable of phase-correct and fast PWM used for functions such as delay() and millis().

How do I set a timer to interrupt AVR?

Steps to configure the Timer Interrupt:

1. Load the TCNT1 register with the value calculated above.
2. Set CS10 and CS12 bits to configure pre-scalar of 1024.
3. Enable timer1 overflow interrupt(TOIE1), the register is shown below.
4. Enable global interrupts by setting global interrupt enable bit in SREG.

How to set timer 1 on an attiny85?

Setting the COM1A0 bit (in combination with also setting the PWM1A bit) in the TCCR1 register puts timer 1 into a mode where timer 1 will continually count from 0 to the value set in register OCR1C and then reset back to 0.

How does a 60 Hz interrupt work on an attiny85?

The 60 kHz signal is generated as a PWM signal using the ATTiny85’s timer2 and timer0 is used to drive a 60 Hz interrupt that controls the transmission of the data bits. The PWM value is varied between a duty cycle of 50/50 to simulate the maximum carrier strength sign and duty cycle of 1/22 to simulate the lower strength signal.

Where is the timsk Register in attiny85?

Upon enabling the Global interrupt bit I in SREG we also need to enable Timer0 associated interrupt. This bit is in a special register called as TIMSK register which is responsible for activating and deactivating interrupts associated with Timer0 and Timer1 peripheral in ATtiny85.

Which is the highest limit for timer0 Register?

Configuration of Timer0 register can be done using two registers TCCR0A and TCCR0B TCCR0A register helps user to configure the Timer to operate in normal mode. This is the mode in which the timer will start the count from 0 and reaches a maximum of 255 which is the highest limit for 8 bit register.