In digital circuits, a flip-flop is a term referring to an electronic circuit (a bistable multivibrator) that
has two stable states and thereby is capable of serving as one bit of memory. Today, the term flip-flop has come
to mostly denote non-transparent (clocked or edge-triggered) devices, while the simpler transparent ones are often
referred to as latches; however, as this distinction is quite new, the two words are sometimes used interchangeably
(see history).
A flip-flop is usually controlled by one or two control signals and/or a gate or clock signal. The output often
includes the complement as well as the normal output. As flip-flops are implemented electronically, they require
power and ground connections. - Wikipedia
These truth tables describe how the outputs of a given flip flop will be determined by a combination of inputs.
Not shown are Preset and Clear inputs, which will cause the "Q" outputs to be set high or low, respectively.
D Flip-Flop
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SR Flip-Flop
0 |
0 |
0 |
X |
0 |
1 |
1 |
0 |
1 |
0 |
0 |
1 |
1 |
1 |
X |
0 |
|
|
T Flip-Flop
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JK Flip-Flop
0 |
0 |
0 |
X |
0 |
1 |
1 |
X |
1 |
0 |
X |
1 |
1 |
1 |
X |
0 |
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X = Don't Care
Q(t) = Present State
Q(t+1) = Next State
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