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Controlled Inverter (Tri-State NOT) in Logisim

Inverting tri-state driver that outputs ~A when Enable is 1 and disconnects to high-impedance Floating (Z) when Enable is 0.

Default settings, facing east. Pins are the dots.
LibraryGates
Type nameControlled Inverter
Pins and defaultsin0 (-20, 0), en (-10, 10), out0 (0, 0), width 1..32

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How the Tri-State NOT Works in Logisim

The Controlled Inverter combines a NOT Gate with a tri-state output stage. When its bottom Enable pin (en) is High (1), it drives the bitwise complement (~in0) onto the output. When Enable is Low (0), it releases the wire into the high-impedance Floating state (Z).

Like the Controlled Buffer, if the Enable pin itself is left unconnected (Z) or receives an error (E), the gate outputs E across all bits.

Tip: Always connect the bottom Enable pin (en) to a defined 0 or 1 signal; a floating Enable pin causes a Controlled Inverter to output E.

Tri-State NOT Pins & Pinout

PinDirectionWidthLocation & Role
in0 (in)Input (Left)1–32 bitsLocated at (-20, 0). Data input to invert when enabled.
en (en)Input (Bottom)1 bitLocated at (-10, 10). Active-high Enable control pin.
out0 (out)Output (Right)1–32 bitsLocated at (0, 0). Outputs ~in0 when en=1, or Z when en=0.

Tri-State NOT Truth Table & Behavior

Controlled Inverter truth table
Enable (en)Data Input (in0)Output (out0)
00, 1, Z, or EZ (floating / disconnected)
101
110
Z or EAnyE

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