It's a trade off - do you prevent interrupts (hence ISR routines) from running during all data critical sections or do you simply not allow those [ISR] functions to execute code that might perturb critical data? eCos chooses the latter method which allows for lower interrupt latency by putting off things until the DSR can be safely run.
Thanks alot. this is exactly what I am searching for. I searched a lot to find it and I read alot but in vain I did not get it. Now I understood it. Once again thanks for your explanation.
monica -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
