Values returned by this SVC can be of limited use for some benchmarking purposes because
of communication overhead or other agent-specific factors. For example, with a debug
hardware unit such as RVI or DSTREAM, the request is passed back to the host for execution.
This can lead to unpredictable delays in transmission and process scheduling.
Use this function to calculate time intervals, by calculating
differences between intervals with and without the code sequence
to be timed.