Microseconds per tick

Thomas Doerfler Thomas.Doerfler at imd-systems.de
Fri Mar 27 09:38:38 UTC 2009


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Leonard,

obviously you are a bit confused by the term "tick". In this
configuration option, a "tick" is the interval between two increments of
the RTEMS-maintained system time.

What you are refering to is the (similar, but different) option

CONFIGURE_CLICKS_PER_MICROSECOND

which defines, how often the HW timer (which generates the system tick
interrupts) is increment per microseconds.

Without knowing the LEON, I would say that if the HW timer is
incremented with 80MHz, you should set CONFIGURE_CLICKS_PER_MICROSECOND
to 80.

And you might set CONFIGURE_MICROSECONDS_PER_TICK to 1000 to get a
system tick/time granularity of 1000us = 1ms.

wkr,
Thomas.


Leonard Bise wrote:
> 
> Hi all,
> 
> I'm quite new to RTEMS and I'm not very experienced so I hope you can
> give me an hand!
> 
> We are working with a board using a LEON2 Sparc processor running at
> 80Mhz, I figured that the microseconds per tick value would be 0.0125
> (is this correct?).
> 
> Shall I simply configure my application with this define ? #define
> CONFIGURE_MICROSECONDS_PER_TICK 0.0125 ?
> 
> I hope you can help, thanks in advance.
> 
> Léonard.
> 
> ps: By the way I posted once using the wrong mail address and it said it
> was awaiting approval from the moderators, please delete this one. This
> is the correct address.
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> rtems-users mailing list
> rtems-users at rtems.com
> http://rtems.rtems.org/mailman/listinfo/rtems-users


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