# The logic behind flip-flop conversion

Discussion in 'Homework Help' started by ADHD, Jan 18, 2011.

Jan 18, 2011
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I got this solved problem in which a D flip-flop is converted into a T flip-flop.

I know what is a flip flop, i understand basic boolean algebra, but i don't understand the steps necesary to convert a flip flop from one type to another.

I've attached a picture with the problem answer.
I don't understand how the data from Q+ and D colums are obtained and why they are the same.

Thanks

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2. ### haykp New Member

Oct 7, 2010
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Each flop has its output equation. For instance the Dff output equation is like Q+ = D and the T output equation is Q+ = Q'.
In your solution these equations are just written in table form

3. ### Georacer Moderator

Nov 25, 2009
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1,266
An example of how to read the truth table. On the first row:
If you have Q=0 and T=0, then you want Q+=0, by definition of the T-FF. But since you are in a D-FF in order to obtain Q+=0 on the output, you have to give it a D=0.

Is that clear?

Jan 18, 2011
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I've tried to convert a T into a D, and i think i got it right. ( T = DQ' + D'Q )

The problem is with the JK flip flop.
I've tried to convert a T into a JK, but i don't know how to fill the map properly.

I've tried several approaches but i didn't get the same expression like the ones found on the internet.

I've attached the table and the map.

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5. ### thatoneguy AAC Fanatic!

Feb 19, 2009
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718
I think that is the one that is not possible. The JK Can be made into anything, but that doesn't mean the T can be made into a JK.

This has come up a few times before, there is an esoteric solution or two (using more than one FF), but nothing like what you've done in the other conversions above.

--ETA: My Bad This info is incorrect, it takes a couple gates, but can be done.

Last edited: Jan 18, 2011

Jan 18, 2011
5
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This is what i've found on the web about T to JK.

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Nov 25, 2009
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