Components / Wiring
Constant Component in Logisim
Supplies a fixed 1-bit (0 or 1) or multi-bit hexadecimal constant value to a wire or bus.
| Library | Wiring |
|---|---|
| Type name | Constant |
| Pins and defaults | out0, width 1..32, value 1 |
How the Constant Works in Logisim
A Constant continuously drives a fixed logic value onto its output pin. Unlike an Input Pin, a Constant does not toggle when clicked with the Poke tool—its value is part of the circuit design and can only be changed in the attribute inspector.
For 1-bit wires, use a Constant set to 1 to tie an unused preset, enable, or T flip-flop toggle input High, or set it to 0 to ground a carry-in pin. For multi-bit buses (width 2 to 32), set the Value attribute to any hexadecimal or binary constant to supply fixed operands to Adders, Subtractors, Comparators, or Shifters.
Tip: Tie the T input of a T Flip-Flop to a Constant 1 to make it toggle on every rising clock edge.
Constant Pins & Pinout
| Pin | Direction | Width | Location & Role |
|---|---|---|---|
| out0 (Constant) | Output | 1–32 bits | Located at (0, 0). Drives the configured constant value continuously. |