Embedded real time software and systems 2010

Those are the real-time systems. In case of an application built for desktop PCs, this can have often random responsiveness delays. Sometimes it can start slightly earlier sometimes it starts harder. But remember: this predictable deadline has nothing to do with speed.

The response has to be within a known limited amount of time, even this is a microsecond, an hour, a day or a month. There are two categories of real-time systems: hard and soft real-time. This categorization left room for many misuderstandings: Is it hard real-time computing the same as high performance computing?

Is it soft real time less important than hard real-time? It is very important to highlight the main difference hard and soft real-time: in case of hard real-time systems the tasks have to be executed in known amount of time otherwise, if this deadline is overpassed, the system may crash and serious damages may be produces often affecting humans lives. In case of soft real time this is not the case, some tolerance is admitted.

Electronics that control critical systems, as a car or an airplane, systems which human lives depend on, are considered to be hard real-time. It is important to get a piece of image or sound on time, but if this does not happen some tolerance is accepted. Nobody will die if the quality of the sound that you are receiving on your phone is poorer, the system can also continue to operate.

Hard real-time systems, even they have a very high level of fiability, they have drawbacks. They are very inflexible and they are more resource expensive than their soft counterparts.

On the other hand soft real time systems trade predictability for efficiency. They can easily adapt to system changes, are less resource consumpting and can smoother tolerate overloads.

So do not necessarily think that hard real time systems have a much higher degree of performance than soft ones. They just are more tuned on certain critical applications. Non-real time embedded systems are not time bounded. They keep the embedded characteristics as little or no user intervention, they are small small memory, limited number of peripherals , they execute a limited number of tasks.

Just imagine a weather station places somewhere where human presence is less accesible. This system is built just for one single thing: read information from several sensors and transmit them via a network link to a base station, meaning a desktop PC. Good reading. What can you make of this point of view — hardware does not really matter, it is just a matter of how that hardware is used in order to categorize it appropriately.

Think about a regular windows kernel. Of course, in user space you can get bored in front of the computer until it launches your app successfully, but in kernel mode, a microsecond is always a microsecond, no matter what. You just need to take care not to start up encrypting anything during an ISR.

No matter what the system load is. Especially between ARM and x86 — complexity-wise. Oh, yes, dumbphones that can only make phone calls and write SMSes — these are embedded systems indeed. Thanks for the appreciations and also for the intervention on this blog!

I cannot say that I fully agree you. Why do you consider smartphones not being embedded devices? I remember that I had some discussions with some workmates also I was reading some web-columns and virtually every attempt to define and embedded system was sticking to two features: size embedded systems are small and do not require user intervention.

It comes with an IDE installable on a symbian device. I am regarding smartphones nowadays as minicomputers. You can do lots with them. GPS routing, voip calls, lot of calculations generally. Even play quake on them. They are definitely not those ultra-specialized devices they used to be.

And yes, they do require user input for that matter — lots. As opposed to dumbphones which can only do a couple of things. Such as dialing a phone call and receiving a phone call. Of course mobile programming nowadays takes care of all these in their kernels, while developers usually only need to concern about the user space.

Live audio-video smartphones are quite fitting this example systems are usually soft real-time; violation of constraints results in degraded quality, but the system can continue to operate. The example with the M language and the IDE that comes with, is quite of niche. Android did this at the right time. They make it and they put an OS onto it. And it is not Symbian, but Android.

AS previously, no! Well, boom, there goes the sky! No one picks them nowadays. If someone wants to come out with a piece of hardware nowadays they hoose Android.

An exception would be Samsung that came out with Bada. No lue to their reasons as they could have stayed on Android or Symbian. It still has its place in the collective memory of smartphone users. But so it does in the memory of developers.

Having iPhones, Androids and Badas nowadays users tend to choose them. Little by little. HAving to choose between the same developers also tend to choose the newer platforms, but at a much higher pace. Combine the convenience of online learning with the immediacy of real-time interaction. Learn More ». By submitting my information, I consent to be contacted and agree to the terms and conditions outlined in the privacy policy. We use cookies to enhance the user experience on our website and deliver our services.

We also use cookies to show you relevant advertising. Read the UW Privacy Policy and more about our use of cookies. Request Information. About this Program Embedded and real-time systems play an integral role in many technology products. Duration: Program Overview Complete the courses listed below to earn the certificate. Learning Format. Online With Real-Time Meetings Combine the convenience of online learning with the immediacy of real-time interaction.

Autumn Oct 11 - Dec See Details. Close and go back to the program overview. Winter Jan 10 - Mar Spring Apr 18 - Jun Lawrence Lo Senior Software Engineer. Subscribe to Keep Learning! Be among the first to receive timely program info, career tips, industry trends and more.