# Digital logic design

Discussion in 'Homework Help' started by ahead, Nov 17, 2012.

Nov 17, 2012
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Hi guys

i have a hard time on the digital logic design problem of the High level state machine. I really need you guys help me out. The attachment is the problem. Please help me. Thanks a lot.

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2. ### spinnaker AAC Fanatic!

Oct 29, 2009
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Do you really expect anyone to help when you have done nothing on your own? Where is your work?

Next time pay attention in class and you would be able to figure this out on your own.

Nov 17, 2012
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I would like to say that most of students have no idea about the problem even though we all pay attention in class. I need some ideas about the problem. I do not expect anyone to finish the problem for me.

Apr 5, 2008
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5. ### WBahn Moderator

Mar 31, 2012
23,160
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You will find that almost everyone here expects you to present your efforts, whatever they may be and however wrong they may be. This is not only because we are not in the game of doing your work for you (which a lot of people that come here do seem to expect), but also because what we want to do is offer hints, suggestions, and lessons that are specifically aimed at the problem you are having. We can't do this unless we can see your attempts and where they went off the rails.

In this case, you need to start by making sure that you (and we) understand what the problem is. So tru explaining, in words, what this machine is accomplishing at each step. Perhaps give some example values for everything and walk through the process of what will happen (known as tracing the system).

6. ### takao21203 AAC Fanatic!

Apr 28, 2012
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Study of state machines for self purpose is not very useful.
After all, a state machine is just a modelling of a real world process.

Sometimes really a state machine is implemented or programmed explicitely.
In many cases, nowadays a sequenced program is run (for instance on a microcontroller).

The := notation is decades old, you can find it for instance used in BCPL, or in PASCAL.

Is it true people really learn Karnaugh, CMOS, state machine, digital logic, and then later use it to produce a circuit or solution?

Or isn't it better first to examine a real world problem, and then see what could be used to implement it?

Or architecture, you can take some clay or LEGO or solder pieces of wires together and design some nice models of buildings. Don't care about maths or how to use some weird CAD software (i.E. to memorize the software menu's, and for instance answer questions about that on paper in a test).

Once you have your 1:100 buildings, start thinking about the underlying maths and physics.

7. ### WBahn Moderator

Mar 31, 2012
23,160
6,974
And this helps the OP complete their assignment... how?

And this helps the OP complete their assignment... how?

So? The '+' notation is centuries old. Should we stop using it?

And, again, this helps the OP complete their assignment... how?

Yes, it is very much true.

Depends on how it is done. A blended approach is probably best.

But, again, this helps the OP complete their assignment... how?

Well, I suppose you could weld a bunch of valves and pipes and gages together and call if a model of a steam punk space ship and then start thinking about the underlying math and physics. So what?

And, again, all of this helps the OP complete their assignment... how?

8. ### takao21203 AAC Fanatic!

Apr 28, 2012
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OK let's do a "blended approach".

Well, I suppose you could weld a bunch of valves and pipes and gages together and call if a model of a steam punk space ship and then start thinking about the underlying math and physics. So what?

I understand your concerns. I just mean it does not make too much sense to pull out an assignment questionaire out of it's context.

In which manner teaching of state machines, digital technology etc. has taken place already? What experiments have they done? What textbooks are they using?

The assignment is highly formalized or let say, it is spelled in a highly formalized way. It is to expect that there will be additional such assignments. Therefore it does not give a good helping to the OP, if we just present a solution.

OP should present some context information, including the type of educational facility. How long are they dealing with this stuff now?

I must say while I use state machine theory for my own work, this assignment does not make too much sense to me. For sure there is some formalized solution or explanation. But that also does not make too much sense to shell it out on it's own.

9. ### takao21203 AAC Fanatic!

Apr 28, 2012
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I am not an imposter. I have read OPs posts again.
So here my contribution:

http://hitechworld.org/pic/StateMachineDesign.pdf

I must really say I do not use this as a starting point to construct a state machine. I use it to understand existing state machines more and in a better way. Most (software) state machines of mine are just state machines of a kind, and it makes sense in no way to press them into the schemes raised in that paper.

It is official AMD stuff so what do you want. Study it, it will be helpful a bit hopefully.

10. ### spinnaker AAC Fanatic!

Oct 29, 2009
7,041
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I would not spend any more time on this until the OP responds with some input. We typically get these posts around this time of year. I guess it is finals week and people panic after they realized they learned nothing in the semester. More often than not they post once or twice then go away.

If the OP wants to respond with some work then OP is well worth helping otherwise your time is probably being wasted.

Apologies to the OP if I am wrong but the post does fit the profile. Scanned image and all to avoid the instructor finding the post.

11. ### takao21203 AAC Fanatic!

Apr 28, 2012
3,783
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Maybe they are not equipped with sufficient study materials, only some cobbled together phrases and excerpts which shall be memorized and repeated in a test, without that much real understanding takes place.

For a complex matter like that, any serious educational institution should apply fair game, and should not be shy to become mentioned on the public internet. Or cease teaching such matters altogether.

12. ### spinnaker AAC Fanatic!

Oct 29, 2009
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Frightening if so. People from those institutions will be designing our devices some day.

13. ### takao21203 AAC Fanatic!

Apr 28, 2012
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Or they are laid off easily. It is just a wrong approach at the foundation.

Maybe the educational institution in question is excellent or not so bad after all. We can not yet know about that.

My opinion is the traditional approach of education is no longer appreciate for modern technology. It is really that fragments end up incorporated into highly absurd scenarios and assignments. If you wanted to build a real world device, you would not work that way.

One time I have really come accross a set of (a bit antiquated as well) textbooks dealing with repair and fault finding within microprocessor circuits. No wonder the industry in that sector is not much existent in our country. I mean who is really doing repair and fault finding within microprocessor circuits? There have been single board computers around some 10 to 15 years ago, with replaceable chips/repairable components. Nowadays, the whole sub-assembly is exchanged.

Nov 17, 2012
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I really appreciate those who really tried to help me out with the problem. And i think i do get some more than from my instructor. The problem is from our second test which everyone did badly. This is why our instructor told us to do it again over the weekend. I tried to get my TA at college but he was out of town. And the materials covered in our class did not help at all. This is why i want to get help from internet. Oh well. Thanks again. I think i just do my best to work on it and hopefully it wil be fine.

Nov 17, 2012
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Anyone who has the right to delete the post, please delete it. I will appreciate it.

16. ### takao21203 AAC Fanatic!

Apr 28, 2012
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There might be papers available on the internet- it's just they are not so easy to find. You really need to search deep, and search repeatedly over time.

Literature and handouts given by the school are not sufficient for a good learning success. You need to buy additional textbooks.

17. ### takao21203 AAC Fanatic!

Apr 28, 2012
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Why? Because your instructor may come accross it? You are not responsible for the actions of other people.

Nov 17, 2012
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Thanks a lot. I was frustrated these days because of the course. I am an EE student and i will graduate in spring semester. I did pretty well in any other course but this digital logic course. I am just a little worried about it might effect my graduation plan if i fail the course.( Although i am still safe so far)
I just want to do my best to get some more from the course. Really appreciate your help.