Skip to main content

Understanding and Mitigating Timing Hazards in Digital Logic Circuits Study Guide

Understanding and Mitigating Timing Hazards in Digital Logic Circuits

Save this study guide to your study set

Sign up free

Your learning path

Combinational Logic Building Blocks and Timing Hazards

Introduction to Timing Hazards

Timing hazards are undesirable changes in the output of a combinational logic circuit caused by gate propagation delays. This includes understanding glitches, static hazards (static-1 and static-0), and dynamic hazards, as well as their relation to Sum-of-Products and Product-of-Sums logic, K-maps, and consensus terms.

  • gate propagation delay
  • glitch
  • static-0 hazard
  • dynamic hazard
  • sum-of-products
  • product-of-sums
  • K-maps
  • consensus terms

Dynamic Hazards in Combinational Circuits

A dynamic hazard is the possibility of an output changing more than once as the result of a single input transition. This section covers dynamic hazards, timing hazards, multi-level multi-paths, hazard-free combinational circuits, Sum of products, prime implicants, synchronous circuits, and D Flip-Flops.

  • Dynamic hazards
  • Timing hazards
  • Multi-level multi-paths
  • Hazard-free combinational circuits
  • Sum of products
  • Prime implicants
  • Synchronous circuits
  • D Flip-Flop

Basic Combinational Building Blocks: Encoders

This lecture covers the design and implementation of basic binary encoders, priority encoders, and BCD to seven-segment code converters using SystemVerilog, including various modeling approaches.

  • Basic Binary Encoder
  • Binary Encoder with Strobe Output
  • Priority Encoder with Strobe Output
  • BCD to Seven Segment Decoder
  • 8:3 Priority Encoder
  • IDLE output
  • SystemVerilog modeling approaches
  • Structural Model
  • Dataflow modeling
  • Behavioral Model
  • casez wildcard
  • Encoder Tree

Combinational Building Blocks: Decoders and Encoders

This lecture covers the design, implementation, and application of combinational building blocks including ROMs, LUTs, decoders, and encoders using truth tables, logic expressions, gate-level implementation, and Verilog modeling.

  • ROMs
  • LUTs
  • Decoders
  • Encoders
  • Active-LOW outputs
  • Active-High Decoders
  • Decoder Tree
  • Boolean function implementation
  • 3:8 Decoder
  • Enable signals
  • High active outputs
  • Low active outputs
  • Minterms
  • Maxterms
  • Memory address decoding
  • Demultiplexer
  • SystemVerilog design
  • Structural modeling
  • Dataflow modeling

Combinational Logic and Verilog Design Objectives

Learning objectives covering K-Maps, logic synthesis, multiplexers, decoders, encoders, and various Verilog modeling approaches for combinational logic circuits.

  • SoP and PoS
  • K-Maps
  • Timing Hazards
  • Multiplexers
  • Decoders
  • Encoders
  • ROM/LUT/FPGA
  • Tri-State/Transmission Gate
  • Verilog structural model
  • Verilog dataflow model
  • Verilog behavioral model
  • Module instantiation
  • Combinational Logic Circuit Design
  • Truth table construction
  • Two-level gate implementation

Logic Minimization and Verilog Combinational Design

Minimization Using Karnaugh Maps

Learn to group adjacent 1s or 0s on K-Maps to generate prime implicants and essential prime implicants for SoP or PoS expressions, considering incompletely specified functions and don't cares.

  • Grouping adjacent cells
  • Prime implicants
  • Essential prime implicants
  • Sum of Products (SoP)
  • Product of Sums (PoS)
  • K-Maps
  • Incompletely specified functions
  • Don't cares

Verilog Design and K-Map Minimization

Explore Verilog design involving bitwise operators, reduction operators, module instantiation, and PoS logic synthesis using K-Maps for applications like a 4-bit bar graph and a 2:4 decoder.

  • Constants
  • Bitwise Operators
  • Reduction Operators
  • Dataflow / Continuous Assignments
  • Module Instantiation
  • Vector / Bus Notation
  • PoS Logic Synthesis Using K-Maps
  • Binary to decimal decoding

Logic Minimization Using K-Maps, SoP, and PoS

Review of logic minimization using K-maps to represent functions in canonical sum-of-products and product-of-sums using minterms and maxterms, covering concepts like literals, product terms, and sum terms.

  • Sum of Products (SoP)
  • Product of Sums (PoS)
  • Minterm
  • Maxterm
  • Canonical sum
  • Canonical product
  • K-map
  • Logic Minimization
  • Literal
  • Product term
  • Sum term
  • Truth table
  • Prime implicants
  • Essential prime implicants
  • Don't cares
  • Incompletely specified functions

Combinational Building Blocks and Multiplexers

This content covers combinational circuits including multiplexers, decoders, encoders, K-Maps, SoP, PoS, and SystemVerilog RTL design, with a focus on gate-level implementation.

  • Multiplexers
  • Sum of Products (SoP)
  • Product of Sums (PoS)
  • K-Maps
  • Minterms
  • Maxterms
  • Truth Tables
  • Decoders
  • Encoders
  • SystemVerilog RTL Design
  • Gate Level Implementation
  • BCD to 7 Segment Code Converter

Verilog Design and Multiplexer Implementation

Verilog designs for multiplexers using primitive gates, dataflow, and behavioral models, including concepts like Mux-Trees and expansion techniques.

  • 2:1 mux Verilog design
  • 4:1 mux implementation
  • Mux-Tree
  • Expansion
  • Dataflow modeling
  • Behavioral modeling
  • Structural model
  • Truth Table
  • Logic Expression
  • Majority Function
  • Two Variable Expansion

Make it your own.

Keep these readings and topics in a new study set, or add them to one you already use.

Get started freeLog in