# Flip-Flop Truth Tables

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
 Q (t) Q (t+1) D 0 0 0 0 1 1 1 0 0 1 1 1
SR Flip-Flop
 Q (t) Q (t+1) S R 0 0 0 X 0 1 1 0 1 0 0 1 1 1 X 0
T Flip-Flop
 Q (t) Q (t+1) T 0 0 0 0 1 1 1 0 1 1 1 0
JK Flip-Flop
 Q (t) Q (t+1) J K 0 0 0 X 0 1 1 X 1 0 X 1 1 1 X 0

X = Don't Care

Q(t) = Present State

Q(t+1) = Next State