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I'm using the program Logisim to create very simple circuits as I am just beginning to learn about the different logic gates and such.

In the Logisism program it has in-built features already such as a Counter, Register, D Flip-Flop etc. I'm trying to create a D Flip-Flop without using the inbuilt features and instead using the logic gates that make it up. I know a D Flip-Flop looks like this: enter image description here

So I created it like the above picture in Logisism, I'm wondering how I can add Clear functionality where if CLEAR is equal to 1 then it resets it.

Another queston I have is using the Logisism program, the in-built D Flip-Flop looks like this:

enter image description here

It has input CLOCK and D with Q and NOT_Q output with a CLEAR. When I try to go to create a sub circuit from the D Flip-flop I made above, it doesn't provide a CLOCK input:

It just has D input and Q, NOT_Q outputs. How do I make CLOCK an input?

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  • \$\begingroup\$ Clear is setting Q to zero, right? I.e. the very same thing D=0 with CLK active doing. So simulate it. As for the second question - if I remember correctly, you can enable different inputs in the parts preferences sheet. \$\endgroup\$ – Eugene Sh. May 2 '16 at 13:42
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So I created it like the above picture in Logisism, I'm wondering how I can add Clear functionality where if CLEAR is equal to 1 then it resets it.

The subcircuit to the right, consisting of the two cross-linked NAND gates, is an R/S flip-flop. You can expose the R and S inputs by adding a third input to each of those gates.

It just has D input and Q, NOT_Q outputs. How do I make CLOCK an input?

The input at the top of the left side, marked with a triangle, is the clock input.

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