# JK flip flop with direct inputs

#### SilverKing

Joined Feb 2, 2014
72
Hi everyone,

What is the logic circuit of JK flip flop with direct inputs (Clear and Preset)?

I need the circuit with AND-NOR and NAND combinations if that possible.

#### tshuck

Joined Oct 18, 2012
3,534

#### crutschow

Joined Mar 14, 2008
30,824
What JK flip flop? Their characteristics vary with model.

What do you mean "with AND-NOR and NAND combinations"?

#### cmartinez

Joined Jan 17, 2007
7,828
There you go... why didn't you just google it?

#### BillB3857

Joined Feb 28, 2009
2,565
My guess is that the OP has the assignment to create the function of a JK-FF using AND, NOR and NAND function blocks and is having difficulty figuring out how to logically represent the DS and DR functions.

#### cmartinez

Joined Jan 17, 2007
7,828
My guess is that the OP has the assignment to create the function of a JK-FF using AND, NOR and NAND function blocks and is having difficulty figuring out how to logically represent the DS and DR functions.

#### cmartinez

Joined Jan 17, 2007
7,828
This oughta do it....

#### BillB3857

Joined Feb 28, 2009
2,565
Sure looks good. I'm sure the OP is grateful for someone doing his homework for him,

#### cmartinez

Joined Jan 17, 2007
7,828
Sure looks good. I'm sure the OP is grateful for someone doing his homework for him,
yeaaaaahhhhhhh wellll.... I was bored, really.....

#### tshuck

Joined Oct 18, 2012
3,534
yeaaaaahhhhhhh wellll.... I was bored, really.....
Regardless, we do not give out answers.

We strive to teach and instruct.

How can we do this if people simply post the answers?

#### cmartinez

Joined Jan 17, 2007
7,828
Regardless, we do not give out answers.
We strive to teach and instruct.
How can we do this if people simply post the answers?
Right... I have two children and know exactly what you mean...

#### cmartinez

Joined Jan 17, 2007
7,828
Right... I have two children and know exactly what you mean...
I wonder if the OP will at least say "thank you"....

#### alfacliff

Joined Dec 13, 2013
2,458
due to the price and scarcity of ttl chips when I was in school, we had to make up the circuits with discrete parts, that will teach you about the individual circuits. they had one 7400 squad nand gate, and passed it around in a plastic box to show us what they looked like.

#### SilverKing

Joined Feb 2, 2014
72
I see a lot of chit-chatting about me being too lazy. Never mind.
And this is not even an assignment, I just wanna make sure from what I'm studying.

My problem that is my instructor gave me this circuit:
http://s9.postimg.org/5625zj7gf/Untitled.png

I'm not really sure of that. Besides, he didn't gave us any method to convert between AND-NOR and NAND combinations, basically he focuses on the AND-NOR combination.

#### tshuck

Joined Oct 18, 2012
3,534
I see a lot of chit-chatting about me being too lazy. Never mind.
And this is not even an assignment, I just wanna make sure from what I'm studying.

My problem that is my instructor gave me this circuit:
http://s9.postimg.org/5625zj7gf/Untitled.png

I'm not really sure of that. Besides, he didn't gave us any method to convert between AND-NOR and NAND combinations, basically he focuses on the AND-NOR combination.
By not trying your own work, you are being lazy. There is no "chit-chat" about it.

Use the fact that you can make any gate function from NANDs, and replace each gate with its NAND implementation. Then, try to minimize it.

#### SilverKing

Joined Feb 2, 2014
72
By not trying your own work, you are being lazy. There is no "chit-chat" about it.

Use the fact that you can make any gate function from NANDs, and replace each gate with its NAND implementation. Then, try to minimize it.
How can I try something that I don't even know about? I didn't know that there's a way to convert AND-NOR to NAND only few minutes prior to my reply.

Anyway, I'll follow what you said and tell how it goes.

Thanks.

#### tshuck

Joined Oct 18, 2012
3,534
How can I try something that I don't even know about? I didn't know that there's a way to convert AND-NOR to NAND only few minutes prior to my reply.
[...]
Are you saying you were never taught about gate universality or that you can use a NAND gate to make an inverter?

#### SilverKing

Joined Feb 2, 2014
72
Are you saying you were never taught about gate universality or that you can use a NAND gate to make an inverter?
No, but I was never that the conversion can be applied on sequential circuits, and not only the combinational circuits.

#### tshuck

Joined Oct 18, 2012
3,534
No, but I was never that the conversion can be applied on sequential circuits, and not only the combinational circuits.
Which gates in your diagram are sequential? All I see are 2 OR, 2 AND, and 2 NOT/inverter gates, no sequential logic there...

They may be arranged in such a way as to become a sequential component, but it is made of combinational parts.