# Odd/Even numbers counter.

Discussion in 'Homework Help' started by TheSpArK505, Dec 13, 2013.

1. ### TheSpArK505 Thread Starter Member

Sep 25, 2013
101
1
Hello guys.

I need to design a counter that works as (even x=0/odd x=1) numbers counter. I,m having difficulties with state diagram.when I begin at 000,x=0 should I stay at this state and when x=0 should I go to 001. And what about the state after this,is it 001,x=0 I go to 010,when x=1 should I go to 011. Is that correct.

2. ### ScottWang Moderator

Aug 23, 2012
5,478
864
Converting all of the functions to the truth table, and using the truth table to build the circuit.

3. ### TheSpArK505 Thread Starter Member

Sep 25, 2013
101
1
do you mean that the states transitions I mentioned are correct.

4. ### ScottWang Moderator

Aug 23, 2012
5,478
864
You can see the truth table of CD4518, and then talk about what you think.

CD4518 datasheet - to see the truth table on the first page..

5. ### tshuck Well-Known Member

Oct 18, 2012
3,527
675
What does the prompt say? Since you are designing it, it could reasonably do any number of things and still count odd and even.

Does this count up? Down? How many bits (from your example, it looks like 3)? What approach? Synchronous?

You need to be much more specific.

6. ### WBahn Moderator

Mar 31, 2012
20,229
5,755
You need to post your best effort at coming up with a state diagram.

Foe each state, describe what, precisely, being in that state means. A good way to do this is to finish the following statement for each state:

If you tell me that I am in state xxx, then I know yyy about the system.

7. ### djsfantasi AAC Fanatic!

Apr 11, 2010
3,496
1,253
I am curious? What is "x"? Is it an input to the logic or an output from it?

And what is the three bit value you are showing? Is it the counter value? How does the circuit count? Is there a separate input to tell the circuit to count?

Try defining the obvious state transitions, first. The others may become clearer after that.

For example, if the counter value is 010 and x=0, what is the next state/value of the counter? Does it or does it not make sense to have the next state be 011?

Just trying to some clarity of your problem.