Timers for Embedded Devices
Timers and counters are essential components of embedded systems. You can use them to measure elapsed time (like counting clock ticks on a processor) or to time an external event. Counter and timer are basically the same devices. The difference lies in how you use them in an application.
Almost every MCU contains one or more timers/counters. To an embedded programmer, their utility is second only to the GPIO (General Purpose Input/Output).
There are many types of timers and it can be confusing to categorize them. One of the popular chips for constructing timers is the 555 timer chip. It is true that the number of companies that manufacture this timer has come down drastically because of competition from the 7555, 7556 or 556 chips series. But some companies have stuck with it which shows that there is some profit left.
The 555 timer is also a favorite with embedded engineers because of its simplicity and the large amount of literature available on its use.
However, don’t be misled. There are many other important timers which also perform neat functions like the ALD1502, ZCST1555, MIC1555/1557, CD4046, LTC6990, XR2209, DS1090, TDC7200 and so on. These are used in different applications and are also among the best in their niche.