Re: [Xenomai-help] RTDM driver structure

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Bob Feretich wrote:
>   Comments inline...
> 
> On 8/5/2010 12:07 AM, Gilles Chanteperdrix wrote:
>> Another remark: Xenomai uses, as, a system timer, a timer in one-shot
>> mode (same as Linux so-called "high resolution timers"), so, if you
>> program several periodic software timers, Xenomai timer subsystem will
>> arrange for your timer callbacks to be called at the right time, so it
>> looks like you will not gain much by using several hardware timers. If
>> you fear that Xenomai timing subsystem will not scale well with many
>> timers, you can enable the heap-based or wheel-based timer management.
> The GPTimers that I am using have special hardware that drives pins on 
> the chip. They can be programmed to create waveforms of specific pulse 
> width and period and auto-restart so that the pulse train is continuous. 
> Software only gets involved when the pulse width or period needs to be 
> changed.  If I used the Xenomai timer, software (to change the state of 
> a GPIO pin) would be invoked every time any of these signals needed to 
> transition.
> 
> Using the hardware timers for the generation pulse trains of fixed pulse 
> width and period takes zero CPU cycles.

Ok. Understood, the software could not even reloead the registers fast
enough.

-- 
					    Gilles.