Logic Gate Simulator
Interactive logic gate simulator (AND, OR, NOT, etc). Enter circuit values to calculate the selected electrical quantity.
Gate Configuration
Electronics guide · Digital logic and number systems
About Logic Gate Simulator
Evaluate a selected one-bit logic gate from binary input values 0 and 1. The simulator supports AND, OR, NOT, NAND, NOR, XOR, and XNOR, then reports the output logic level and expression.
Digital logic tools work with discrete states and number representations. Binary values can be interpreted differently depending on bit width, signed or unsigned representation, and the operation selected. Keep those conventions in view when comparing a result with a circuit, processor, or programming language.
How to Use This Tool
- 1.Choose a gate from the selector.
- 2.Set input A and, for two-input gates, input B to 0 or 1.
- 3.Calculate and compare the output with the gate's truth table. NOT uses input A only.
Technical Details to Check
1.Bit width changes interpretation
A bit pattern has no single signed value until its width and number convention are known. Fixed-width operations can wrap around or discard bits when a result exceeds the available width.
2.Separate logical and arithmetic operations
AND, OR, and XOR act on individual bits; addition and subtraction combine numeric values. Confirm the selected operation and distinguish a logical shift from an arithmetic shift where relevant.
3.Truth tables show input combinations
A gate's output depends on its defined inputs. For a larger circuit, check the input order and follow each intermediate signal rather than assuming that the output label alone explains the logic.
4.Representations can look different
The same value may appear in binary, decimal, or hexadecimal. Leading zeros can preserve a chosen width, while a displayed result may omit them unless the tool is configured to show fixed-width output.
How the Calculation Works
The simulator treats each input as a Boolean bit. AND is 1 only when both inputs are 1; OR is 1 when either is 1; XOR is 1 when inputs differ. NAND and NOR invert AND and OR, XNOR is the inverse of XOR, and NOT flips a single input.
Worked Example
For A=1 and B=0, AND returns 0, OR returns 1, and XOR returns 1. For NOT A with A=1, output is 0.
Where This Tool Can Help
Practice digital logic, check truth-table rows, and understand how basic gates combine in circuits.
Learning base conversion
Compare the binary result with its decimal or hexadecimal form to see how place values represent the same quantity.
Checking a small logic expression
Use the selected gate or bitwise operation to check a truth-table row or a small example before implementing it in a larger design.
Reviewing firmware values
Check a bit mask or arithmetic example, then repeat it with the target integer width and signedness used by the firmware or hardware.
Teaching digital concepts
Use a compact input to explain gate behavior, binary digits, and why the same bit pattern can have more than one numeric meaning.
Tips for More Reliable Results
- Count the bits and write down whether the value is signed or unsigned before interpreting it.
- Use small values first and verify a result by converting it to another displayed base.
- Check how the destination language or device handles overflow, shifts, and leading zeros.
- For a logic circuit, verify every input combination and signal order, not only one convenient example.
Limitations and Assumptions
This is a logical truth-table model, not a voltage-level simulator. It does not model propagation delay, fan-out, noise margins, analog behavior, or multi-bit buses. Real logic families have electrical specifications and thresholds.
A logic or number result is meaningful only with its input order, operation, bit width, and representation conventions. The page does not automatically verify that those match a specific processor, HDL, programming language, or physical logic circuit.
Frequently Asked Questions
Why does NOT have only one input?
It is a unary gate that inverts a single logic value.
What does XOR mean?
It outputs 1 when the two inputs are different.
Does a logic 1 always mean 5 volts?
No. Voltage levels depend on the logic family and supply; the simulator only uses abstract 0 and 1 values.
Can the same binary digits mean different values?
Yes. Width and signedness affect how a bit pattern is interpreted.
Why did a fixed-width answer wrap around?
The result may have exceeded the available bits, so higher bits were discarded under that operation's rules.