Overview of real-time embedded systems for non-embedded developers

Heinz-J=FCrgen Oertel wrote: [snip]

Thanks. But what I need is to find some specific material: *principles* of real-time embedded systems for *non-embedded developers* to get starting.

Alex Vinokur email: alex DOT vinokur AT gmail DOT com

On 23 Sep 2005 22:12:12 -0700, "Alex Vinokur" wrote in comp.arch.embedded:

I think you are asking the wrong question. You are confusing two different concepts, although they do often occur in the same systems.

There are embedded systems, and there are real-time systems, with varying degrees of real-time "hardness". You can certainly have either without the other although, as I said above, many embedded systems also have hard real-time requirements.

Now you have added a third topic, one that is not necessarily related to either of the other two. You are talking about hardware devices that require some sort of specific software, commonly called device drivers, to control.

Hardware devices and drivers exist in all computer systems, whether or not they are embedded and/or have real-time requirements. Just for example, every single operating system that you can run on a 32-bit x86 PC, which includes MS-DOS, any version of Windows, Linux, BSD, Solaris, QNX, VxWorks, and the upcoming Mac OSX for x86, have to provide device drivers for the keyboard, mouse, hard disks, floppy disks, CD and DVD drives, MODEMs, real time clock, system timer, interrupt controller, DMA controller, serial and parallel ports, and more.

A few of these operating systems, particularly Solaris, QNX, and VxWorks, have specific properties to allow hard real-time requirements to be met. Most of the others do not. Yes each one of those systems needs device drivers for each of the hardware devices I mentioned above, and the driver for each device is different for each OS.

As others have said, the topics of "embedded systems", "real-time systems", and "device drivers" are very broad. I'd suggest that you might do well to start by picking one of those topics to start investigating.

Thank you very much. Your (conceptual) answer was very useful.

Alex Vinokur email: alex DOT vinokur AT gmail DOT com

Articles at

Richard

Starting out from

rgds Peter

Hi Folks, was reading the archives for just this kind of information ( the non-embedded developer getting into embedded space [and real time this time]). I am a Mechanical Engineer into programming (C programming for networking device) for quite some time now. I have recently been assigned to a project which requires *Embedded Knowledge* according to the Lead. Can any one tell me the nuances of Embedded Device Progg vs. Embedded Application Progg. I have read the device specifications and have understood the memory map. Any other pointers will be greatful.

Regards, _Ajai.Jose_

-- Ajai [ dot ] Jose [ at ] gmail [ dot ] com above line is to save time from unsolicited spam by now u know how to reach me ;-)

I think embedded systems is very vast domain. You first identoify in which area you want to work..like embedded application programming, firmware development, embedded middleware development, driver development etc... You can refer following few books :

Embedded Systems Building blocks by Jean Labrosse The art of embedded system design by jack ganssle The firmware handbook by jack ganssle visit few sites like embedded.com

As others have noted, the term 'embedded systems' covers a really wide range of activities, which may or may not have a processor (in that wider sense, an embedded system has embedded functionality of some description, which may have been achieved in pure hardware).

If you are speaking of embedded controllers, then embedded.com has some good articles (although there's a lot of ads).

Cheers

PeteS