AVR Timer programming Revision as of 12:25, 18 November 2014 by Sandeep (Talk | contribs) (diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Basics

Timers come in handy when you want to set some time interval like your alarm. This can be very precise to a few microseconds. Timers/Counters are essential part of any modern MCU. Remember it is the same hardware unit inside the MCU that is used either as Timers or Counter. Timers/counters are an independent unit inside a micro-controller. They basically run independently of what task CPU is performing. Hence they come in very handy, and are primarily used for the following:

• Internal Timer: As an internal timer the unit, ticks on the oscillator frequency. The oscillator frequency can be directly feed to the timer or it can be pre-scaled. In this mode it used generate precise delays. Or as precise time counting machine.
• External Counter: In this mode the unit is used to count events on a specific external pin on a MCU.
• Pulse width Modulation(PWM) Generator: PWM is used in speed control of motors and various other applications.

Timers/Counters in AVR

Timer 0

Timer 0 Registers

TCNT0: Timer/Counter Register 0

Timer/Counter 0

TCNT0
D7	D6	D5	D4	D3	D2	D1	D0

TCCR0: Timer/Counter Control Register

TCCR0
D7	D6	D5	D4	D3	D2	D1	D0
FOC0	WGM00	COM01	COM00	WGM01	CS02	CS01	CS00