From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4E1ADF1B.50904@domain.hid> Date: Mon, 11 Jul 2011 13:31:39 +0200 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <201107101841.28583.carlosnov@domain.hid> In-Reply-To: <201107101841.28583.carlosnov@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Advice on clock sources for xenomai rtdm driver List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Carlos Eduardo de Brito Novaes Cc: xenomai@xenomai.org On 07/10/2011 11:41 PM, Carlos Eduardo de Brito Novaes wrote: > Hello all. > > I woud like to ask you some opinion about timers. > I am slowly working on a real time driver for a acquisition board. It can be > configured for read up to 32 anaalog channels and has a internal timer that wil > start the conversion on a programmed time (its a 8254 timer) or the PC ca send > a command to start conversions to. Sadly, there is no interrupt generated by > this board, so if using the internal timer the driver has to keep polling some > io ports to check for data and if any, retrieve it. > If I can setup a (precise) timer to trigger an interrupt, so I can start the > conversions and on a know time read back the data. But the interrupt rate > would be about 1K or a bit more, so RTC would not be a good idea, I think. I > also read about HPET but it seens to have issues with xenomai and also I read > that for some reason, some interupts would be lost. Do you guys recommend me > something? Should I stick with polling and set up some delays with > usleep_range or there is a good timer on PC boards and weel supported with > xenomai? If you are writing an rtdm driver, why not using rtdm timers? http://www.xenomai.org/documentation/xenomai-2.5/html/api/group__rtdmtimer.html -- Gilles.