Introduction

The PE Examinations are now beginning to include digital logic. Questions in digital logic can be expected to be included in future PE Exams.

This chapter presents general principles with which you should be familiar.

A basic review of the field should include the following subjects:

Number Systems

• Bases other than 10

• Conversion between bases

• Negative numbers

Truth Functions

• Logical reasoning

• Binary connectives

• Physical realizations (AND, OR, NOT; inclusive/exclusive OR)

Boolean Algebra

• Huntington's postulates, duality

• Truth calculus vs. Boolean algebra (+, X, )

• DeMorgan's theorem

• Venn diagram

• Boolean simplification

Switching devices

• Gates

• Flip-flops

Minimization of Boolean functions

• Terms (literal, product, sum, normal, conjunction, disjunction)

• Minterms and maxterms, prime implicants

• Karnaugh map (graphical method of minimization)

• Quine-McClusky method (tabular method of minimization)

Codes and Special Realizations

• Error detection and correction

• Parity check

• Adder (half, full)

• BCD

• Gray (reflected)

• Excess-3

• Hamming

• Distance

Sequential Circuits

• Shift registers

• Counters

• Clocked circuits, sequencers

• Timing considerations

• State diagrams

• Mealy-Moore translations and circuits

• Cycles, races, hazards

Definition of Terms, Postulates, Properties

The following terms are used in the field of logic design:

Connectives