Data flip flops

how to make them, what they do, and how they work

To follow along with me go to and complete all of the levels up to the data flip flop. (though the website is called nandgame I won’t show how to make everything with just nand gates)

Data flip flops probably have a better name but their website calls them that so I will just go with it.
Data flip flops are a way to store and emit two different values. It is controlled by a store value a value to store and a clock signal.

st means store. d is just an indicator for what value to store and cl is the clock signal.
The latch circuit is used in both instances to store a value and emit one.

A latch emits/outputs what it stores, the conditions for storing 1 in a latch are st = 1 and d = 1. To store 0 just change d; st = 1 and d = 0. When you turn off the st value the d value remains stored and is emitted as the output the whole time.

This is why data flip flops are important. We need to change the value being stored before emitting it. To do this we need another input which dictates when to emit the stored value.
The data flip flop is even more complex than this though. The clock value only makes the stored value become emitted when it changes from 0 to 1, not from 1 to 0. Another important part is that once the clock signal is changed to 1 changing the value of d will not affect the stored value which also means the emitted value is unaffected.

The final part of the blog is how to make one.

Now I am done so I think I will go program

if there are questions email me at

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