unsigned long timer_ns2tick(unsigned long ns);
Convert a value in nanoseconds to hardware timer ticks, which allows you to compare it to a value returned by timer_diff().
The accuracy of the return value is dependent on the resolution of the hardware timer tick and the time it takes to read the hardware timer.
For more information and a code example that adds a wait time and converts nanoseconds to hardware timer ticks, see timer_start()
The number of hardware timer ticks.