unsigned timer_diff(unsigned start);
Given a value returned by timer_start(), read the hardware timer's current value and return the difference since timer_start() was called. This function provides the difference in number of hardware ticks.
You can use timer_tick2ns() to convert the value returned to nanoseconds.
When you implement this function, keep the following information in mind:
For more information and code examples that use this function, see by timer_start().
The number of hardware timer ticks since time_start() was called.