High Resolution Timer

An important property of operating systems is the precision of alarms; this in turn affects the resulting interrupt load. The alarm mechanism of an OSEK operating system is based on counters which are incremented by either software or hardware timers. When a counter reaches a preset alarm value, a predefined action is executed. The typical time resolution of such timers is 1ms.
If timer resolutions with a higher precision than 1ms are required, osCAN and MICROSAR OS offer a high resolution timer mechanism that can achieve these enhanced precisions. Resolutions in the microsecond range are possible depending on the controller used.

Features and Advantages:

The high resolution timer permits high-precision alarms with a lower system interrupt load (depending on hardware). An interrupt is only triggered when an alarm actually becomes due.
The precision of the alarm time depends only on the resolution and clock frequency of the hardware timer. It may range from 100ns to 100µs depending on the microcontroller.

Functions:

"Collective" processing of several consecutive alarms can be controlled by defining a minimum interval between timer interrupts. This reduces interrupt load, especially when several alarms with similar due times elapse almost simultaneously.

Application Areas:

The high resolution timer was designed for applications which require high-precision timers but cannot tolerate additional interrupt loads.

Data sheet High Resolution Timer