Lpc2000

Hi Guille,
I've been working on a preemptive RTOS over the last two years (on and
off...) with the features you are looking for, namely:
- takes advantage of CPU low-power modes in an automatic, transparent way
- has a high degree of responsiveness to external events
- supports deadlines to a sub-microsecond resolution
Basically, "don't do anything unproductive". I wrote it out of
frustration with currently available RTOSes: power
efficiency is at best an afterthought, and always subject to tradeoffs
like reactivity.
I have the basic kernel, and already used it in two 210x based
projects so far (developed with GCC).
I am currently playing with the idea of eventually either having it
open-sourced, or make it available for a one time per-product fee
(royalty-free) through my employer, socsolutions.com.
Having said that, you are welcome to give it a try.
Alfredo

--- In lpc2000@yahoogroups.com, "guillermoprandi"
<yahoo.messenger@m...> wrote:
>
> Hi! I am building a board featuring the LPC2138 µC. This board will 
> basically need to interface with three serial devices (two via 
> internal UARTs and a third via MAX3100, though suggestions are 
> welcomed about this). This device must be very low power; it should 
> wake up only when needed, which is: 1) there's data available from 
> any of the three ports, 2) there's data waiting to be transmitted on 
> any of the ports and the port becomes free and 3) a periodical 
> overall check (every second or so). This means that theoretically the 
> processor can enter the idle state quite often. I'm looking for some 
> (free if possible) multithreaded OS that would handle the transition 
> to the processor's idle state on traditionally blocking calls like 
> fread() and fwrite(), expecting to wake up on interrupt; also, some 
> preemptive multitasking should be supported, in case some thread 
> enters an exceptionally long calculating task. Probably there's no 
> known OS that directly supports this; in this case, I'd like to know 
> which other OS might be a good starting point to accomplish this by 
> making the modifications myself. I'm aiming to use the GNU libraries 
> (I ignore how difficult or messy would it be to modify them to 
> support this). Finally, it is my understanding that the VERY low 
> power "power down" mode would not be useful for my application, since 
> the peripherals (therefore the UARTs and SPI) are shut down in this 
> mode. Any advise or hint on these subjects will be greately 
> appreciated.
> 
> Guille
>