Simple Flip-Flops / Latches

A simple guide that shows basic Flip-Flops, how they work and how to make them.

General

"In electronics, a flip-flop or latch is a circuit that has two stable states and can be used to store state information." Flip-flops are made of smaller components called logic gates. This guide shows how they work and how to make them in Logic World

SR latch

SR or Set-Reset latches are used to set the output to 1 with S input and reset to 0 with R input.
SR latches take two inputs and give one output based on input combination as following:

S	R	Q
0	0	Q
1	0	1
0	1	0
1	1	X*

*X - forbidden state

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Diagram:


In-game:

JK latch

JK latches are similar in behaviour as SR latches, but instead of having the forbidden state, they have the "flip" state, which means the next output is going to be inversed current output.
JK latches also take two inputs and give one output based on input combination as following:

J	K	Q
0	0	Q
1	0	1
0	1	0
1	1	Q'

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Diagram:


In-game:

As seen, JK latch has an additional signal CP or CLK (Clock) which controls how often inputs affect the latch. Easiest way to make a clock is to connect output of a delayer to input of inverter and vice versa. Any node can be used as an output. Notice that frequency can be changed by editing the delayer.

T Latch

T latches have one input connected to both inputs of an JK latch so it only has the "flip" state.
T latches take one input and give one output based on input combination as following:

T	Q
0	Q
1	Q'

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Diagram:


Notice the diagram has a clock, but I haven't used it because I added the delayers inside the circuit.

In-game:

Conclusion

That's all I managed to do for now, I will update it when I can. This guide is not finished, I still have to make the D latch and maybe add some other things. Hope this helped at least a little bit.

Happy engineering

[Zathros]

Thanks for taking the time to post this!

[April Derg]

As a useful note that would have saved me tons of trouble, the SR latch is very sensitive to the clock timings, and so making your own pulse with a button for testing purposes will not work.

[_KJ__]

To make a flip flop the easy way is to use an inverter and an and gate to generate a 1 tick pulse into a d-latch that has its output ran through an inverter to the input on said d-latch. the inverter and AND gate get connectd with the output of inverter one one inputer of the and gate and the input of the inverter to the other input of the and gate, then setting the inverter high will trigger the and gate, then after 1 tick the inverter's output will turn off. The 1 tick is enough for the latch to flip the inverter and save state.