Boolean Algebra

Boolean algebra is the math behind digital electronics, using just two values: 0 (false) and 1 (true). It’s the foundation for designing all digital circuits and computers.

Core Operations

These three operations are the building blocks of all digital logic -

  1. AND (·) - Outputs 1 only if both inputs are 1.
  2. OR (+) - Outputs 1 if at least one input is 1.
  3. NOT (¬ or !) - Flips the input.

Key Rules for Simplification

Boolean algebra uses rules to simplify complex logic, making circuits efficient

  • Identity: A + 0 = A, A · 1 = A
  • Null: A + 1 = 1, A · 0 = 0
  • Idempotent: A + A = A, A · A = A
  • Complement: A + ¬A = 1, A · ¬A = 0
  • Distributive:
    • A · (B + C) = A·B + A·C
    • A + (B · C) = (A + B) · (A + C)

Logic Gates

Boolean operations come to life as logic gates in electronic circuits. These gates are wired together in chips to perform tasks like addition, memory storage etc., forming a backbone for digital electronics.

OperationGateBehavior
A · BAND1 only if both A and B are 1
A + BOR1 if A or B is 1
¬ANOTInverts A (0 → 1, 1 → 0)

basic-logic-gates

Derived Gates

  • NAND: ¬(A · B)
  • NOR: ¬(A + B)
  • XOR: A ⊕ B - Outputs 1 if inputs differ (A or B, but not both).
  • XNOR: ¬(A ⊕ B) - Outputs 1 if inputs are the same.

derived-logic-gates