Help understanding this asynchronous sequential circuit please

• Engineering
• momentum
In summary: Yes, "-,-" in the table means you are suppose to fill those in. I don't understand what the other notation is. In summary, the book has given an incorrect table for state transitions.
momentum
Homework Statement
fundamental mode circuit
Relevant Equations
NA
I am finding difficulty in understanding the sequence transition graph

My Book has given solution like this

Question : I have marked red circle in the above table. ...book has given E but I think it should be F ...What is correct here E or F ?

Here is the state diagram given in the book

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I don't see how statement #2 can be simplified. It is a very straight-forward description of sequential behavior.

Perhaps you are confused because one can't do a simple truth table for states in sequential transitions. Those are for static circuits where sequencing doesn't enter into it. In this case you'll have to draw waveforms (squarewaves) showing the various possible states.

phinds said:
It is a very straight-forward description of sequential behavior.

I have edited my question and defined the problem area now. Could you please take a look at it again ?

momentum said:
I have edited my question and defined the problem area now. Could you please take a look at it again ?
And do what?

EDIT: Oh, sorry. I see there IS a question in there.

phinds said:
And do what?

I have marked red circle in the above table. ...book has given E but I think it should be F ...What is correct here E or F ?

I don't see any definition of what those "present state" letters stand for

phinds said:
I don't see any definition of what those "present state" letters stand for
A,B,C etc...these are just usual transitions states.

momentum said:
A,B,C etc...these are just usual transitions states.
Sorry, I don't have no idea what that means, "usual transition" states. How are they defined? What, for example, is "present state C" ?

phinds said:
Sorry, I don't have no idea what that means, "usual transition" states.

No problem. I'll figure out the solution. thanks

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Yes, there are conflicts between the state diagram and the state transition table. It looks like they are for different problems?

berkeman
DaveE said:
Yes, there are conflicts between the state diagram and the state transition table. It looks like they are for different problems?

I suspect that this is a printing mistake in state transition table. Can you please confirm this ?

my book shows E (red circle) in the table but I think it should be F ( as per the state diagram).

I am fine with the state transition diagram.

It seems book has printed mistakenly E ( instead of F) in the table... right ?

momentum said:
I suspect that this is a printing mistake in state transition table. Can you please confirm this ?

my book shows E (red circle) in the table but I think it should be F ( as per the state diagram).

I am fine with the state transition diagram.

It seems book has printed mistakenly E ( instead of F) in the table... right ?
I suppose yes, but there are other discrepancies in addition to that. I'm not too motivated to find all of the errors. Frankly it is easier to just make the correct table from the diagram (or vice-versa) than it is to analyze how someone else did it wrong.

What I haven't done is match either the diagram or the table up to the words, I suspect that would be the best approach. You have three descriptions of the system, and I know two don't agree.

The table shows direct transitions C→E, D→C, E→C, F→A, and F→D. None of these are shown in the state diagram.

I guess "-,-" in the table means you are suppose to fill those in? Otherwise, I don't understand that notation.

1. What is an asynchronous sequential circuit?

An asynchronous sequential circuit is a type of digital circuit that uses feedback to store and process information. It consists of a series of interconnected logic gates and flip-flops, and its output depends not only on the current inputs but also on its previous state.

2. How does an asynchronous sequential circuit work?

An asynchronous sequential circuit operates in an asynchronous manner, meaning that the output can change at any time based on the inputs and the current state of the circuit. The circuit uses feedback to store information in its flip-flops, and the output is determined by the combination of the current inputs and the stored information.

3. What is the difference between synchronous and asynchronous sequential circuits?

The main difference between synchronous and asynchronous sequential circuits is the way they handle timing. In synchronous circuits, the output changes only at specific clock intervals, while in asynchronous circuits, the output can change at any time based on the inputs and the current state of the circuit.

4. What are some common applications of asynchronous sequential circuits?

Asynchronous sequential circuits are commonly used in digital systems that require memory and feedback, such as counters, shift registers, and state machines. They are also used in communication systems, control systems, and data processing systems.

5. How can I better understand an asynchronous sequential circuit?

To better understand an asynchronous sequential circuit, it is important to have a strong understanding of digital logic and basic circuit design principles. It may also be helpful to study specific examples and practice designing and analyzing these circuits. Additionally, seeking guidance from a mentor or taking a course in digital logic can also aid in understanding asynchronous sequential circuits.

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