Hi,

Where can I find the ISR for each interrupt, e.g., SFD interrupt when a
packet is received? Is it part of TinyOS implementation? Thanks.

On Wed, Aug 10, 2011 at 11:04 AM, Janos Sallai
<[email protected]>wrote:

> Have you thought of modifying each and every ISR routine to store (and
> accumulate) the time spent serving interrupts? This accumulated value
> should then be subtracted from the running time of the code snippet.
>
> I suggest that you directly read the counter registers in the ISRs
> (vs. calling LocalTime.get(), which may have additional overhead). The
> counter registers should not overflow more than once while the
> interrupt handler is running.
>
> This gets a little tricky, though, if there are nested interrupts.
> AFAIK it's only the ADC subsystem that uses nested interrupts on the
> AVR platforms. If your application doesn't use the ADC, the above
> simple solution would suffice.
>
> Janos
>
>
>
> On Tue, Aug 9, 2011 at 10:27 PM, Xiaohui Liu <[email protected]> wrote:
> > Hi everyone,
> > How can I measure the time for a snippet of code (e.g., a function call
> > foo), either synchronous or asynchronous, to execute?
> > A straight forward way can be:
> > start_time = Call LocalTime.get();
> > foo();
> > end_time = call LocalTime.get();
> > (end_time - start_time) is regarded as the execution time of function
> call
> > foo(). However, asynchronous code can preempt foo() during its execution,
> > thus (end_time - start_time) may be overestimation of foo()'s actual
> > execution time.
> > An alternative can be something like the following:
> > disable interrupt;
> > start_time = Call LocalTime.get();
> > foo();
> > end_time = call LocalTime.get();
> > enable interrupt;
> > However, this can be problematic also if some critical interrupts (e.g.,
> > packet reception) occur when the interrupt is disabled. Can anyone have
> some
> > idea on how execution time can be measured without the above issues? Any
> > help is appreciated.
> > --
> > -Xiaohui Liu
> >
> > _______________________________________________
> > Tinyos-help mailing list
> > [email protected]
> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
> >
>



-- 
-Xiaohui Liu
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