This is the mail archive of the ecos-discuss@sources.redhat.com mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: accurate ms delay


Jesper Skov wrote:
> 
> On Fri, 2002-03-08 at 12:26, Jani Monoses wrote:
> >
> > Is it OK to use hal_delay_us in a generic .inl driver instead of the
> > not-too-accurate for loops?
> 
> Yes, it's always a preference over for loops. Just be carefull to not
> delay with the interrupts disabled.

And obviously it can be no more accurate than the resolution of the clock
device feeding it.
 
> >Is this function guarranteed to be implemented
> > by every platform?
> 
> Yes - there is a fall-back implementation that is just a for-loop. So
> accuracy is not guaranteed. But since RedBoot rely on the function, it's
> available (and fairly accurate) on most platforms.

Although having a fallback has problems when it works "good enough" most
times and it's only in QA for customer releases that we sometimes find it
hasn't been implemented!

Jifl
-- 
Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
Maybe this world is another planet's Hell -Aldous Huxley || Opinions==mine

-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]