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Re: problems with RTC
- From: Nick Garnett <nickg at ecoscentric dot com>
- To: Michele Paselli <miguelon at tiscali dot it>
- Cc: <ecos-discuss at ecos dot sourceware dot org>
- Date: 11 Apr 2007 10:12:53 +0100
- Subject: Re: [ECOS] problems with RTC
- References: <55208.1176207327833.JavaMail.root@ps5>
Michele Paselli <miguelon@tiscali.it> writes:
> Hi all,
>
> I'm developing a radio driver for an AT91 platform and I need to
> change the time granularity in order to make some precise latency
> measures. In order to have a frequency multiplied by 10 (1 KHz since
> the default is 100Hz) I multiplied by 10 the CYGNUM_HAL_RTC_DENOMINATOR
> parameter. I also modified the CYGNUM_KERNEL_TIMESLICE_TICKS parameter
> in order to have the same timeslice interval as I would have in the
> default conditions. The ticks are now indeed 1 every millisecond, but
> the radio driver does not seem to work properly anymore. In particular,
> the driver seems to miss come interrupts. The only call to a function
> related to timers in the driver is a timeout counter but I multiplied
> its value by 10 to have the same conditions as before. Can anyone
> suggest me a possible cause? I think that the conditions for the driver
> in terms of timing are the same as before, but maybe I'm missing
> something.
I don't have any suggestions for fixing your driver, in theory
everything you have done is correct. I have run many eCos
configurations with a 1KHz clock with no problems.
Something you should check is that the clock ticks are arriving at the
expected rate. Try running the clocktruth kernel test against a
stopwatch to check this.
--
Nick Garnett eCos Kernel Architect
eCosCentric Limited http://www.eCosCentric.com/ The eCos experts
Barnwell House, Barnwell Drive, Cambridge, UK. Tel: +44 1223 245571
Registered in England and Wales: Reg No 4422071.
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