• Logisim home page
• Guide to Being a Logisim User
  • Beginner's tutorial
    • Step 0: Orienting yourself
    • Step 1: Adding gates
    • Step 2: Adding wires
    • Step 3: Adding text
    • Step 4: Testing your circuit
  • Libraries and attributes
    • The explorer pane
    • The attribute table
    • Tool and component attributes
  • Subcircuits
    • Creating circuits
    • Using subcircuits
    • Debugging subcircuits
    • Logisim libraries
  • Wire bundles
    • Creating bundles
    • Splitters
    • Wire colors
  • Combinational analysis
    • Opening Combinational Analysis
    • Editing the truth table
    • Creating expressions
    • Generating a circuit
  • Menu reference
    • The File menu
    • The Edit menu
    • The Project menu
    • The Simulate menu
    • The Window and Help menus
  • Memory components
    • Poking memory
    • Pop-up menus and files
    • Hex editor
  • Logging
    • The Selection tab
    • The Table tab
    • The File tab
  • Application preferences
    • The Template tab
    • The Tools tab
    • The International tab
    • The Experimental tab
    • The command line
  • Project options
    • The Canvas tab
    • The Simulation tab
    • The Toolbar tab
    • The Mouse tab
  • Value propagation
    • Gate delays
    • Oscillation errors
    • Shortcomings
  • JAR libraries
    • Gray Code Incrementer
    • Library Class
    • Simple Gray Code Counter
    • Gray Code Counter
    • Guidelines
  • About the program
    • GNU General Public License
• Library Reference
  • Base library
    • Poke Tool
    • Edit Tool
    • Select Tool
    • Wiring Tool
    • Text Tool
    • Menu Tool
    • Splitter
    • Pin
    • Probe
    • Clock
    • Text
  • Gates library
    • Constant
    • NOT Gate
    • Buffer
    • AND/OR/NAND/NOR Gate
    • XOR/XNOR/Even/Odd Gate
    • Controlled Buffer/Inverter
  • Plexers library
    • Multiplexer
    • Demultiplexer
    • Decoder
    • Priority Encoder
    • Bit Selector
  • Arithmetic library
    • Adder
    • Subtractor
    • Multiplier
    • Divider
    • Negator
    • Comparator
    • Shifter
  • Memory library
    • D/T/J-K/S-R Flip-Flop
    • Register
    • Counter
    • Shift Register
    • Random
    • RAM
    • ROM
  • Input/Output library
    • Button
    • Joystick
    • Keyboard
    • LED
    • 7-Segment Display
    • Hex Digit Display
    • LED Matrix
    • TTY
  • Legacy library
    • Logisim 1.0 D/J-K Flip-Flop
    • Logisim 1.0 8-Bit Register

Negator

Library:	Arithmetic
Introduced:	2.0 Beta 22
Appearance:

Behavior

Computes the two's-complement negation of the input. This negation is performed by maintaining all the lower-order bits up to the lowest-order 1, and complementing all bits above that.

If the value to be negated happens to be the least negative value, then its negation (which cannot be represented in two's-complement form), is still the least negative value.

Pins

West edge (input, bit width matches Bit Width attribute)

The value to negate.

East edge, labeled -x (output, bit width matches Bit Width attribute)

The negation of the input. If the input happens to be the least negative value representable in bitWidth bits, however, then the output matches the input.

Attributes

Data Bits

The bit width of the component's input and output.

Poke Tool Behavior

None.

Text Tool Behavior

None.

Back to Library Reference