Logisim 1.0 D/J-K Flip-Flop

Library: Legacy
Introduced: 2.0 Beta 12


These components exist only for backwards compatibility with Logisim 1.0X; for new circuits, the Memory library's flip-flops are recommended instead.

Each flip-flop stores a single bit of data, which is emitted through the Q output on the east side. Normally, the value can be controlled via the inputs to the west side. In particular, the value changes when the clock input, marked by a triangle on each flip-flop, rises from 0 to 1; on this rising edge, the value changes according to the corresponding table below.

D Flip-Flop J-K Flip-Flop
00 Q
01 0
10 1
11 Q'
Another way of describing the different behavior of the flip-flops is in English text.


West edge, marked by triangle (input, bit width 1)
Clock input: At the instant that this input value switches from 0 to 1 (the rising edge), the value will be updated according to the other inputs on the west edge. As long as this remains 0 or 1, the other inputs on the west edge have no effect.
West edge, other labeled pin(s) (input(s), bit width 1)
These inputs control how the flip-flop's value changes during the rising edge of the clock. Their exact behavior depends on the flip-flop; the above tables summarize their behavior.
East edge, labeled Q, north end (output, bit width 1)
Outputs the value currently stored by the flip-flop.
East edge, south end (output, bit width 1)
Outputs the complement of the value currently stored by the flip-flop.



Poke Tool Behavior


Text Tool Behavior


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