Embedded System

QNX DEVELOPERS Realtime and Embedded
1

Hi,
Can anybody explain what is Embedded System?
Krishnan

2

For such a broad definition, I’m sure others will have to amend what I say here, but here goes. An embedded system is a computer with software that has some fixed purpose, rather than being a general purpose computer. Embedded systems may look very different from a normal desktop or laptop computer. They may not have a monitor or keyboard or mouse. They may not have a unique user interface. They often will come coupled with some specialized hardware.

3

I guess giving an example of them will also make it clear.
DVD players, X-box, GPS systems, etc…
these can be all considered as an embedded system.

4

Ok, a few more then. Medical instruments with embedded computers, Car engines (I’ve heard new cars have 10 or more processors), Oil tanker engine control systems. Tivo. IPod, Cell Phones, Computer Printers and Scanners, …

5

Thank you maschoen & jinma ,
If i understand correctly, these are programms designed for specific operation and loaded in the Chip and used for execution. The exe file will be loaded in the Chip for the process.
So these will be for specific task or purpose.
Correct me if i am wrong.
Which is the main language used for designing the same.
Regards,
Krishnan.

6

An embedded system might be just a program loaded in the Chip as you say, but often an entire OS is part of the embedded system.
As you point out, the purpose is almost always for a specific task or purpose.
While QNX works fine on a desktop, the main thrust of marketing QNX today is towards embedded systems.
For QNX ‘C’ and ‘C++’ are the main languages, however Java seems to be getting more and more interest. For embedded systems in general, there is probably no overwhelming trend. Some of the earliest embedded systems I’ve seen used Forth. Embedded systems on 8 bit chips are often written in assembler.

7

Thanks maschoen,

Is there any specific OS on which Embeded System runs.
So, if i am right mostly, Embeded System mostly runs on QNX
Or is it OS dependent.

And will there will not be any downtime for these system and are they free from virus attack.

Regards,
Krishnan.

8

The concept of Embedded system is mostly hardware, aSome OS will make the experience easier, or will be a better suited for to deeply embedded system; I don’t see XP or Solaris 10 for example running on a Mips processor using 16Meg of ram. Nor do I see QNX running on an 8bit processor ;-)

9

Using the broad definition of “Embedded System” there is no particular OS that defines a device as being an embedded system. There is no reason why XP, OS/MVS, UNIX, or Multics cannot be the OS. In fact, an OS is not even required. That said, a lot of embedded systems these days are being built using medium size processors with OS’s. Some OS’s are better suited. You bring up an important reason. Reliability is usually important. This for a number of reasons. Imagine if your new HD TV crashed every few months. Yes most TV’s now embedded systems. It wouldn’t be long before no one would buy your brand of TV. Consumer expectations are just one reason that reliability is needed. In the case of some automated gambling machines, reliability is mandated by state authorities. The FDA has a lot to say about medical equipment.

Most embedded systems are fairly hardened against viruses, because there is usually no method of entry. An exception might be a game box with a hard drive. Tivo also comes to mind.

10

Thanks maschoen,
I am currently working on Mainframes. Just out of intrest i asked about Embeded System.
U have given me a good understanding of this. I hope this is a vast one.

I just want to know more about this, could you please suggest me some links or some book for reading.

Thanks/Regards,
Krishnan.