Verilog Functions and Tasks

Study Material

Traffic Signal Controller

Study Material [PPT]

The following specifications must be considered:

• The traffic signal for the main highway gets highest priority because cars are continuously present on the main highway. Thus, the main highway signal remains green by default.

• Occasionally, cars from the country road arrive at the traffic signal. The traffic signal for the country road must turn green only long enough to let the cars on the country road go.

•As soon as there are no cars on the country road, the country road traffic signal turns yellow and then red and the traffic signal on the main highway turns green again.

• There is a sensor to detect cars waiting on the country road. The sensor sends a signal X as input to the controller. X = 1 if there are cars on the country road; otherwise, X= 0.

• There are delays on transitions from S1 to S2, from S2 to S3, and from S4 to S0. The delays must be controllable.

Find Verilog Code in the PPT.

Behavioral Description study materials

•• The significance of structured procedures always and initial in behavioral modeling.

•• Define blocking and nonblocking procedural assignments.

•• Understand delay-based timing control mechanism in behavioral modeling. Use regular delays, intra-assignment delays, and zero delays.

•• Describe event-based timing control mechanism in behavioral modeling. Use regular event control, named event control, and event OR control.

•• Use level-sensitive timing control mechanism in behavioral modeling.

•• Explain conditional statements using if and else.

•• Describe multiway branching, using case, casex, and casez statements.

•• Understand looping statements such as while, for, repeat, and forever.

•• Define sequential and parallel blocks.

•• Understand naming of blocks and disabling of named blocks.

•• Use behavioral modeling statements in practical examples.

Data flow description Study materials

Learning Objectives

• Describe the continuous assignment (assign) statement, restrictions on the assign statement, and the implicit continuous assignment statement.

• Assignment delay, implicit assignment delay, and net declaration delay for continuous assignment statements.

• Define expressions, operators, and operands.

• List operator types for all possible operations.

arithmetic, logical, relational, equality, bitwise, reduction, shift, concatenation, and conditional.

• Use dataflow constructs to model practical digital circuits in Verilog.

Gate Level Description Study Materials

Identify logic gate primitives provided in Verilog.
• Understand instantiation of gates, gate symbols, and truth tables for and/or and buf/not type gates.
• Understand how to construct a Verilog description from the logic diagram of the circuit.
• Describe rise, fall, and turn-off delays in the gate-level design.
• Explain min, max, and typical delays in the gate-level design.

Modules and ports Study Materials

Identify the components of a Verilog module definition, such as module names, port lists, parameters, variable declarations, dataflow statements, behavioral statements, instantiation of other modules, and tasks or functions.
• Understand how to define the port list for a module and declare it in Verilog.
• Describe the port connection rules in a module instantiation.
• Understand how to connect ports to external signals, by ordered list, and by name.
• Explain hierarchical name referencing of Verilog identifiers.

Module 2 chapter 1 Study materials
Basic Concepts, Lexical conventions, data types, system tasks, compiler directives.

Verilog HDL Module 1 Chapter 2

Module 1 Chapter 2 Study Material
Hierarchical Modeling Concepts:
Top-down and bottom-up design methodology, differences between modules and
module instances, parts of a simulation, design block, stimulus block

Verilog HDL Module 1

Module 1 Chapter 1 Study Material
Overview of Digital Design with Verilog HDL
Evolution of CAD, emergence of HDLs, typical HDL-flow, why Verilog HDL?, trends in
HDLs.