Re: What does 'embedded' really mean?

Steve at fivetrees wrote:

"Tim Wescott" <tim@xxxxxxxxxxxxxxxx> wrote in message news:742dnQIXdZtzs9vYnZ2dnUVZ_vCdnZ2d@xxxxxxxxxxxxxxx

Mike Noone wrote:


I was recently asked what 'embedded' really means, and I did not have a
good answer. Can anybody try to define it? I just am not sure as to a
concrete definition - I only can give examples of what is and what
isn't embedded.


I take the term "embedded processor" to mean any processor that's embedded into a system, the purpose of which is _not_ to present my processor in a pleasing aspect -- so while the Pentium that is helping me write this is in some sense embedded in the PC, it's not really embedded.

On the other hand, the MSP430 that's controlling the little levitating dingle-ball by my elbow* _is_ embedded, even though I can see through the clear plastic of the evaluation kit from TI to the processor.


Another definition of "embedded" is "has a single job to do", i.e. does not run user-defined application code. So, while your Pentium isn't embedded, the processor in your hard drive is - it has a single job to do, namely managing the hard drive subsystem. Ditto with a USB device, or an old-style graphics controller, or the keyboard...

Yes, but you can play semantic games with that one. Obviously the Pentium in this here machine has one job to do (make me happy), and it's doing it -- but it still isn't embedded.

This is why whole articles get written...

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

"Applied Control Theory for Embedded Systems" came out in April.
See details at http://www.wescottdesign.com/actfes/actfes.html
.