Forums

rtos features

Started by Sagar June 22, 2004
hello,

i am evaluating various rtos for on of our products based on arm7. i
have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii.
Of the lot Threadx and embOS seem to be good. Although i believe that
the others are just as good. It seems hard to zero in one choice. I
have been searching for reviews in the newsgroups. I have found some
scattered info for nucleus and threadx (threadx apparently seems to be
better).

I am primarily looking at these features:
Scheduling, events, queues, low interrupt latencies, small mem
footprint, fast context switching, ....

I would appreciate if somebody could post their views/experiences on
these rtos'.


Thank you
Sagar
On 21 Jun 2004 21:38:25 -0700, mailsagr@yahoo.com (Sagar) wrote:

>hello, > >i am evaluating various rtos for on of our products based on arm7. i >have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii. >Of the lot Threadx and embOS seem to be good. Although i believe that >the others are just as good. It seems hard to zero in one choice. I >have been searching for reviews in the newsgroups. I have found some >scattered info for nucleus and threadx (threadx apparently seems to be >better). > >I am primarily looking at these features: >Scheduling, events, queues, low interrupt latencies, small mem >footprint, fast context switching, ....
You maybe should consider Sciopta as well :-) 100% Assembly. Designed for low-mem to high-speed applications. -- 42Bastian Do not email to bastian42@yahoo.com, it's a spam-only account :-) Use <same-name>@epost.de instead !
"Sagar" <mailsagr@yahoo.com> wrote in message
news:b0a2c083.0406212038.1c80d905@posting.google.com...
> i am evaluating various rtos for on of our products based on arm7. i > have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii. > Of the lot Threadx and embOS seem to be good. Although i believe that > the others are just as good. It seems hard to zero in one choice. I > have been searching for reviews in the newsgroups. I have found some > scattered info for nucleus and threadx (threadx apparently seems to be > better).
I have direct experience with ThreadX (in a source level license) and found it to be solid, well debugged, and the support to be outstanding. It has been excellent to us (we've shipped about 30 products with it). -->Neil
Did you consider VxWorks? VxWorks has been around for a long time and
is quite stable.

Sandeep
--
http://www.EventHelix.com/EventStudio
EventStudio 2.0 - Real-time and Embedded System Design CASE Tool
In article <b0a2c083.0406212038.1c80d905@posting.google.com>, mailsagr@yahoo.com (Sagar) wrote:
>hello, > >i am evaluating various rtos for on of our products based on arm7. i >have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii. >Of the lot Threadx and embOS seem to be good. Although i believe that >the others are just as good. It seems hard to zero in one choice. I >have been searching for reviews in the newsgroups. I have found some >scattered info for nucleus and threadx (threadx apparently seems to be >better). > >I am primarily looking at these features: >Scheduling, events, queues, low interrupt latencies, small mem >footprint, fast context switching, ....
You should take a look at CMX-RTX from CMX Systems ( http://www.cmx.com ) also. CMX-RTX has all the features you are looking for and no royalties! CMX-RTX runs on the ARM7 and about 30 other microprocessors including DSPs. Paul Bosselaers
Sagar wrote:
> hello, > > i am evaluating various rtos for on of our products based on arm7. i > have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii. > Of the lot Threadx and embOS seem to be good. Although i believe that > the others are just as good. It seems hard to zero in one choice. I > have been searching for reviews in the newsgroups. I have found some > scattered info for nucleus and threadx (threadx apparently seems to be > better). > > I am primarily looking at these features: > Scheduling, events, queues, low interrupt latencies, small mem > footprint, fast context switching, .... > > I would appreciate if somebody could post their views/experiences on > these rtos'. > > > Thank you > Sagar
I am very partial to MicroC/OS-II. It offers all the features you list including fast context switching. It has been ported to all kinds of chips based on ARM7 and ARM9 cores and the ports are available freely from Micrium's web site. Jean Labrosse published a book on the OS (available on their web site or from Amazon) and the book includes a CD with all of the source code. You can have it all for about US$70. A production license is under $3000. MicroC/OS-II has also been tested extensively for use in safety critical systems. -- Scott ExoTech R&D, Inc.
"Sagar" <mailsagr@yahoo.com> wrote in message
news:b0a2c083.0406212038.1c80d905@posting.google.com...
> hello, > > i am evaluating various rtos for on of our products based on arm7. i > have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii. > Of the lot Threadx and embOS seem to be good. Although i believe that > the others are just as good. It seems hard to zero in one choice. I > have been searching for reviews in the newsgroups. I have found some > scattered info for nucleus and threadx (threadx apparently seems to be > better). > > I am primarily looking at these features: > Scheduling, events, queues, low interrupt latencies, small mem > footprint, fast context switching, .... > > I would appreciate if somebody could post their views/experiences on > these rtos'. >
What about Real-Time Linux? There's a free version available that I've used for years in pseudo PCs but they also have versions for a variety of uPs. Norm
"Not Really Me" <scott@exoXYZtech.com> wrote in message
news:RMXBc.17$7e3.7669@news.uswest.net...
> Sagar wrote: > > hello, > > > > i am evaluating various rtos for on of our products based on arm7. i > > have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii. > > Of the lot Threadx and embOS seem to be good. Although i believe that > > the others are just as good. It seems hard to zero in one choice. I > > have been searching for reviews in the newsgroups. I have found some > > scattered info for nucleus and threadx (threadx apparently seems to be > > better). > > > > I am primarily looking at these features: > > Scheduling, events, queues, low interrupt latencies, small mem > > footprint, fast context switching, .... > > > > I would appreciate if somebody could post their views/experiences on > > these rtos'. > > > > > > Thank you > > Sagar > > I am very partial to MicroC/OS-II. It offers all the features you list > including fast context switching. It has been ported to all kinds of
chips
> based on ARM7 and ARM9 cores and the ports are available freely from > Micrium's web site. Jean Labrosse published a book on the OS (available
on
> their web site or from Amazon) and the book includes a CD with all of the > source code. You can have it all for about US$70. A production license
is
> under $3000. > > MicroC/OS-II has also been tested extensively for use in safety critical > systems. >
When you say a production license is under $3000, what sort of quantities is that for? Do they make a distinction between a product with, say, 50 units a year, and one with several thousand? And do you need a seperate license for different products (or different versions of the same product)?
Not Really Me wrote:

> I am very partial to MicroC/OS-II. It offers all the features you list > including fast context switching. It has been ported to all kinds of chips > based on ARM7 and ARM9 cores and the ports are available freely from > Micrium's web site. Jean Labrosse published a book on the OS (available on > their web site or from Amazon) and the book includes a CD with all of the > source code. You can have it all for about US$70. A production license is > under $3000. > > MicroC/OS-II has also been tested extensively for use in safety critical > systems. >
Sadly it's too expensive for me, I'll have to stick to ecos! I do a lot of small quantity products, and while I suppose I could argue that all my products are just variants, I can't afford to get into an argument, so that's that. Paul Burke
Thanks guys for the feedback. I should have mentioned the chip specs
earlier:
it is an arm7tdmi-s with: 512 KB program flash, 32KB data flash, 32 KB
ram.

with these tiny resources, I am begining to feel that embOS
(www.segger.com) may be my choice. All other RTOSes that i had
mentioned before seemed to occupy too much space in flash or they
needed more resources in RAM.

for eg: for the features that i mentioned before, embos requires: 
kernel space in flash: 6.4 KB
kernel ram usage: 51 bytes
ram per task: 32 bytes

the only apparent negative aspect to it compared with other RTOSes
like threadx seems to be the context switch time(18us vs 1.9us of
threadx) and interrupt latency (max 6us vs 1.8us of threadx). but
threadx uses more ram per task. maybe threadx stores a lot of process
info in ram and hence has to save less while switching.

Regards
Sagar

mailsagr@yahoo.com (Sagar) wrote in message news:<b0a2c083.0406212038.1c80d905@posting.google.com>...
> hello, > > i am evaluating various rtos for on of our products based on arm7. i > have been looking at Nucleus, embOS, Rtxc, Threadx and MicroC os-ii. > Of the lot Threadx and embOS seem to be good. Although i believe that > the others are just as good. It seems hard to zero in one choice. I > have been searching for reviews in the newsgroups. I have found some > scattered info for nucleus and threadx (threadx apparently seems to be > better). > > I am primarily looking at these features: > Scheduling, events, queues, low interrupt latencies, small mem > footprint, fast context switching, .... > > I would appreciate if somebody could post their views/experiences on > these rtos'. > > > Thank you > Sagar