This function samples the current system time, and returns it to you. The primary return value is the seconds count of the system clock. A secondary value available in the r1 register on ARM processors is the microseconds count of the system clock. For a C-friendly version of this call, see SampleSystemTimeTV().
This function has very low overhead and is meant for high-accuracy timings.
The time value returned by this function corresponds to the time maintained by the TIMERUNIT_USEC unit of the timer device.
Return Value
This function returns the seconds count of the system clock. It also returns the microseconds count in the r1 ARM processor register.