I think it just resets when the CPU is powered up, but never thought of looking
into it
since always have used it as a relative time difference (endtime-starttime).
It would probably be hard to synchronize to an external (high accuracy) clock as
its count is so fast
that the non-deterministic (timewise) operation of any program would be off by
some significant count
by the time any set instruction could be run.
Skybuck Flying wrote:
> Hi,
>
> I have some questions about the high performance counter.
>
> 1. When the power is off does the high performance counter continue to tick
> ?
>
> 2. If not then how is the high performance counter initialized at boottime ?
>
> 3. Where can I find more information about the chip(s) for the high
> performance counter ?
>
> 4. Is it possible to reset the high performance counter via a software call
> ?
>
> 5. How is the frequency related to the hardware ? I know it's different per
> processor... but is it for example different depending on memory speed ? or
> does it always have a fixed frequency ?
>
> ( note: I changed the windows xp system time to see what would happen, it
> did not affect the high performance counter, so it seems not related to each
> other )
>
> p.s.: I know it's off-topic in some newsgroups I posted too but euhm... I
> didn't know what newsgroup was best suited for it, I hope you understand 
>
> Thank you,
> Skybuck.