# State Diagram for sequence 001

Discussion in 'Homework Help' started by Buchan, May 23, 2011.

1. ### Buchan Thread Starter New Member

Jan 11, 2011
7
0
i have just covered Sequence Detectors and the state diagrams. However , i can not seem to complete the 001 state diagram. can anyone help. This is what i have so far. Please excuse the daigram. It was done on paint

2. ### jegues Well-Known Member

Sep 13, 2010
735
43
You are currently using 2 bits to represent 4 states. If you wish to represnt a fifth state, you must first use a minimum of 3 bits.

EDIT: I clearly misunderstood the problem statement.

Last edited: May 23, 2011
3. ### Buchan Thread Starter New Member

Jan 11, 2011
7
0
Im not following you. Im new to this subject. We are given a sequence (in this case 001) and our diagrams have S0-S3. All that is missing is where state 3 goes when the input becomes 1. Im sorry for being so vague.

4. ### Buchan Thread Starter New Member

Jan 11, 2011
7
0
i should point out also 0,1 is not 01 0 is what is being entered to the sequence , 1 is the input

5. ### Georacer Moderator

Nov 25, 2009
5,151
1,266
By convention, when you write some numbers over the transition lines, these follow the format I/O, or I, meaning the Input that has led you to take that transition and optionally the output that the mentioned transition will produce.

You have written X,Y over your lines and since your input is 1 bit long (you examine one bit of your input each time) Y can only be interpreted as an output.

I will not examine Y for now, I just want you to notice that from each state, each arrow must have a different input. It is meaningless to follow two paths for the same input.

That said, from state S2, (1,0) must point to either S3 or S0. The same goes for all the other states.

If that was a typo and the lower arrow from S2 was meant to be (0,0), then you are on the right path.

But think of the following. If you are to take that path, you have already read three '0' in a row. If you receive a '1' after that, shouldn't that lead you to your goal?

Think of what I said and repost a diagram.

EDIT: After reading your last post, I must say that what is being entered in the sequence and the input of the machine is the same thing. Maybe you want to write only one bit over your transitions.