Logisim 1.0 D/J-K Flip-Flop
||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
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.
Another way of describing the different behavior of the flip-flops
is in English text.
- D Flip-Flop: When the clock rises from 0 to 1, the
value remembered by the flip-flop becomes the value of the D
input (Data) at that instant.
- J-K Flip-Flop: When the clock rises from 0 to 1,
the value remembered by the flip-flop
if the J and K inputs are both 1,
remains the same if they are both 0,
and changes to the K input value if J and
K are not equal. (The names J and
K do not stand for anything.)
- 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 input(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
Poke Tool Behavior
Clicking a flip-flop using the Poke Tool toggles the bit stored in
the flip-flop, unless the asynchronous set/reset inputs currently
pin the flip-flop's value.
Text Tool Behavior
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