Lecture 6: Timers, Counters, PWM

Question 1

Can a timer keep the time even if the processor is off?

Answer 1

Yes

Question 2

What are the 3 sources that a clock can run off?

Answer 2

Quartz clock
Pre scaled clock
External clock

Question 3

What is the max prescaler on Timer 0?

Answer 3

1023 - > 10 bit

Question 4

On Timer 0, what is the direction of count?

Answer 4

Always up

Question 5

What happens to Timer 0 when it reaches its max value?

Answer 5

it will overrun and then reset, starting from the bottom. We can set an overflow interrupt for code to execute when the timer reaches its max value.

Question 6

With NO prescaling, what is the timeout period of Timer 0?

Answer 6

Range / Clock Frequency

Question 7

What is the formula for 1 tick period?

Answer 7

1 / clock frequency

Question 8

In what Register do we set the prescaler for the timers?

Answer 8

Timer0: TCCR0
Timer1: TCCR1B
Timer2: TCCR2

Question 9

In PWM generation, what is the dutycycle formula?

Answer 9

Pulsewidth / period