On Wed 24 Sep 2008 13:06, Fundu pondered: > > >>> what about Non maskable interrupts ? disabling > > >>> interrupt won't have any effect on that > > right ? > > >> > > >> that really doesnt make sense by definition huh. > > >> non-maskable means > > >> they cant be masked. > > > > > > yeah thats the point. i should have elaborated more. > > > then there's no guarantee that your code wont be > > interrupted ? Disabling interrupts does not normally mask NMI, reset, exceptions and emulation. All can interrupt your code. Most do not return (except exceptions) - so it is not a big deal. exceptions - also depend heavily on your processor type/architecture - but can range from TLB miss/dirty - to unaligned access fixups. On Blackfin - we don't do unaligned access fixups - this has the upside of when your code does this - it crashes - so you tend to find it early :) The downside is that the code which functions (slowly) on other architectures does not run on Blackfin... > > design your system properly and it wont be an issue > > could you elaborate more on this, as to what you mean by good design in > this context. If you have something that is timing critical - make sure - by design - that you will not cause exception events. In most Blackfin systems that is done by ensuring that the TLB for the kernel is covered and locked. You never get a ITLB miss in kernel code, and a DTLB miss only occurs on kmalloced data. (which you shouldn't be acessing) > > you about the Blackfin processor, but i doubt you're > > using that. > > sure i would like to know. i also have a 537 which i would work on for > the next project and don't mind more info on it. It really depends on what you are trying to do. If you are that timing critical - you want to put things into internal L1 memory - so you don't take the penalty of cache misses/flushes either... -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
