ABSTRACT
A counter is a more general version of a timer. Many microcontrollers that include built-in timers will have special interrupts just for its timers, with those interrupts distinct from external interrupts. The watchdog timer can be considered as a special type of timer. It is important to note that, it is also possible to design the watchdog timer hardware so that a reset signal that occurs too soon will cause the watchdog timer to reset the system. Two commonly used types of counters are binary counters and linear-feedback shift registers. Normally the timers of the microcontrollers can fulfill all the modes of operation of the programmable interval timer. Timers are the most commonly device used in embedded and digital systems. The majority of the microcontrollers have one or more build-in timer/counter. The chapter discusses the counter unit, the timer prescaler and input selector the features that are common to all of the timers.
