I think toolchain forum is not the best place to ask this question. Try 
OS forum

On 12-12-07 02:57 AM, Andreas Beschorner wrote:
> Greetings fellows,
>
> I have two rather nasty problems, both sort of connected to each other.
>
> 1) The first deals with the famous timer quantization problems. Following the QNX timer documentation, the smallest 
quantization seems to be about 0.999847 or so milliseconds. For periododic timers/ triggers on integer millisecond base 
this does not pose such a big problems, losing jsut about every 6300th timer or so. However, I need a way more accurate 
timer to down to microseconds or, in other words, a trigger for instance every 7.333 milliseconds. I take it this will 
not be working and implies (as our tests show) a catastrophic jitter? Please tell me I am mistaken :-)
>
> 2) Again for reasons of accuracy: Any way of knowing whether QNX disables CPU throttling or if not (what I do not 
expect for a real time OS) how to disable it?
>
> Thanks a lot for help,
> Andy
>
>
>
>
> _______________________________________________
>
> General
> http://community.qnx.com/sf/go/post97894
> To cancel your subscription to this discussion, please e-mail general-toolchain-unsubscribe@community.qnx.com

Andreas,

1)  QNX 6 doesn't have high resolution timers. AFAIK ... it's using the 
IRQ 9 for its system tick.
2)  simply no

Regards

--Armin


Andreas Beschorner wrote:
> Greetings fellows,
>
> I have two rather nasty problems, both sort of connected to each other.
>
> 1) The first deals with the famous timer quantization problems. Following the QNX timer documentation, the smallest 
quantization seems to be about 0.999847 or so milliseconds. For periododic timers/ triggers on integer millisecond base 
this does not pose such a big problems, losing jsut about every 6300th timer or so. However, I need a way more accurate 
timer to down to microseconds or, in other words, a trigger for instance every 7.333 milliseconds. I take it this will 
not be working and implies (as our tests show) a catastrophic jitter? Please tell me I am mistaken :-)
>
> 2) Again for reasons of accuracy: Any way of knowing whether QNX disables CPU throttling or if not (what I do not 
expect for a real time OS) how to disable it?
>
> Thanks a lot for help,
> Andy
>
>
>
>
> _______________________________________________
>
> General
> http://community.qnx.com/sf/go/post97894
> To cancel your subscription to this discussion, please e-mail general-toolchain-unsubscribe@community.qnx.com
>