OR Gate

The two-input OR gate implements inclusive Boolean OR: its output is HIGH when either or both sampled inputs are HIGH, and LOW only when both are LOW.

Overview

The two-input OR gate implements inclusive Boolean OR. Its output is HIGH when either or both sampled inputs are HIGH.

DigiSim Interface

Direction	Pins	Behavior
Input	A, B	Two one-bit operands.
Output	Y	Driven Boolean result.

Truth Table

Y = A + B in Boolean notation. A defined HIGH determines the result even when the other input is X; otherwise a relevant driven unknown produces X. A released Z input follows Logic Lab's LOW sampling convention.

Simulation Boundary

This is a functional two-input gate, not a model of a specific IC, diode network, transistor topology, or electrical load.

Learning Path

Prerequisites

AND Gate

Next Steps

NOT Gate NOR Gate XOR Gate

Frequently Asked Questions

What is an OR gate?

An OR gate outputs 1 (HIGH) when at least one of its inputs is 1. It only outputs 0 when all inputs are 0.

What is the truth table of an OR gate?

For a 2-input OR gate: 0 OR 0 = 0, 0 OR 1 = 1, 1 OR 0 = 1, 1 OR 1 = 1. The output is HIGH when any input is HIGH.

What is the difference between OR and XOR?

For the two-input gates documented here, OR outputs HIGH when either or both inputs are HIGH, while XOR outputs HIGH only when the inputs differ. More generally, multi-input XOR represents odd parity.