Components / Gates
NOT Gate (Inverter) in Logisim
Logical inverter that flips 0 to 1 and 1 to 0 bit-by-bit across single wires or multi-bit buses.
| Library | Gates |
|---|---|
| Type name | NOT Gate |
| Pins and defaults | in0 (-30, 0), out0 (0, 0), width 1..32 |
How the NOT Works in Logisim
The NOT Gate (or inverter) computes the logical complement (~A) of its input. Drawn as a triangle with an inversion bubble at the tip, it outputs 1 when its input is 0, and outputs 0 when its input is 1.
When Data Bits (width) is set above 1, the NOT Gate performs a bitwise inversion across all N bits of the bus ( computing the ones' complement). If any input bit is floating (Z) or in conflict (E), that bit position outputs E.
Tip: Combine a NOT Gate with an Adder (setting cin = 1) to subtract in two's complement: A - B = A + (~B) + 1.
NOT Pins & Pinout
| Pin | Direction | Width | Location & Role |
|---|---|---|---|
| in0 (in) | Input | 1–32 bits | Located at (-30, 0) relative to output. Input signal to invert. |
| out0 (out) | Output | 1–32 bits | Located at (0, 0). Outputs bitwise ~in0. |
NOT Truth Table & Behavior
| Input A | Output Y = ~A |
|---|---|
| 0 | 1 |
| 1 | 0 |
| Z (floating) | E |
| E (conflict) | E |