On 2/5/06, Michael Schippling <[EMAIL PROTECTED]> wrote:
> Oh, now here is an interesting bit of trivia....
> TimerC overflows a 16bit count every 2 sec.
>
> But the interface has a resolution of 1ms,
> and there has been talk about what the max
> timeout when using the i/f is?

For the MSP430 in tinyos-1.x, the max timeout is something like 2^26
or 2^27 milliseconds --  about 18 hours.

> And the lack of wiring vs not including in
> the config file...hmmm? Is the Timer always
> started in StdControl.init() even if not used?

TimerM.nc is wired to a counter overflow interrupt in the MSP430,
which is handled regardless of StdControl.

> I've probably missed a really important piece
> of documentation...Can you elucidate a bit?
>
> thx
> MS
>
>
> Cory Sharp wrote:
> > None of the drivers in TinyOS are written to be able to sustain a task
> > taking long seconds or more to complete.  Blocking the task queue for
> > a long time is bad.  Read the discussion pointed to my Michael.  You
> > must split your long task into multiple tasks, each task incrementally
> > doing more processing.
> >
> > For the MSP430 TimerC in particlar, every two seconds, for each
> > overflow of a 32khz 16-bit counter, a task is posted to process that
> > overflow.  The current overflow MUST be processed before the next
> > overflow occurs.
> >
> > For a healthy, reactive system, I recommend no one task take longer
> > than, say, tens of milliseconds to complete.
> >
> > Cory
> >
> > On 2/5/06, Matt Thompson <[EMAIL PROTECTED]> wrote:
> >> Hi,
> >>
> >> It appears that TimerC is filling the task queue while a long task is
> >> running (ie Elliptic Curve DSA signature verification).  After the ECDSA
> >> task completes, the telosb is unable to process any more tasks.  Is
> >> there a way to stop the timer from posting tasks before a long operation
> >> is started?  It seems that even if I do not start the timer (and it is
> >> not wired to StdControl), the task queue still fills up.  I have to
> >> completely remove it from the configuration for this behaviour to 
> >> disappear.
> >>
> >> Why does the mote not continue to process the task queue after the long
> >> task completes, and then allow me to post more tasks when some of them
> >> have completed?
> >>
> >> Has anyone else expereienced similar behaviour?
> >>
> >> Cheers,
> >> Matt
> >> _______________________________________________
> >> Tinyos-help mailing list
> >> [email protected]
> >> https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
> >>
> >
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>

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