Digital Logic Design
PROF. SHEHZAD ALI
Overview
Number system
Binary Numbers
Boolean Algebra
Switching Algebra
Logic Gates
Boolean Function
Basic Identities of Boolean Algebra
The basic rules listed in the table have been arranged into two
columns that demonstrate the property of duality of Boolean
algebra.
The dual of an algebraic expression is obtained by interchanging OR
and AND operations and replacing 1s by 0s and 0s by 1s.
Basic Identities of Boolean Algebra
DeMorgan’s Theorem
Algebraic Manipulation
Boolean algebra is a useful tool for simplifying digital circuits. Consider, for example, the Boolean
function represented by
The expression is reduced to only two terms and can be implemented with
gates as shown in Figure 4(b).
Algebraic Manipulation
Truth Table for Boolean Function
Algebraic Manipulation Examples
Algebraic Manipulation Examples
Complement of a Function
EXAMPLE Complementing Functions
EXAMPLE Complementing Functions by Using Duals

Digital logic design lecture 3