A common tick counter period in real-time systems is 1.024 ms (don't ask me why!). That works out at 50.9 days
Originally Posted by
pilotmike
It is because 16MHz / 2^14 gives a period of 1.024ms, ie. 976.5625Hz
This is just one example..There is no common implementation.. although OS system ticks in the order of 1 to 10 ms. is common. (For big OS'es)
Real-time systems interfacing directly with hardware are often have much faster system tick and OS preemptive interrupts.
And almost all CPU's today have a clock faster than 16MHz. (i.e. prescaler values need to be larger than 2^14 to divide to 1ms. )
For PC hardware google
High Precision Event Timer and cpu
Time_Stamp_Counter