What is a Timer
Timer is a clock that controls the sequence of an event while counting in fixed intervals of time. A Timer is used for producing precise time delay. Secondly, it can be used to repeat or initiate an action after/at a known period of time. This feature is very commonly used in several applications. An example could be setting up an alarm which triggers at a point of time or after a period of time.
Timers in a controller: Why to use them
Most of the microcontrollers have inbuilt Timers. Timers in a controller not only generate time delays but they can also be used as counters. They are used to count an action or event. The value of counter increases by one, every time its corresponding action or event occurs. Timers in a controller are inbuilt chips that are controlled by special function registers (SFRs) assigned for Timer operations. These SFRs are used to configure Timers in different modes of operations.
While working with microcontrollers, it is more than often required to generate time delays. There are two possible ways of generating time delays. First is by using the code, like using for or while loops in a C program. However, the delays provided by the software are not very precise. The other method is to use Timers. Timers provide time delays that are very precise and accurate.