Table of Contents
What is a hierarchical reference?
A hierarchical reference data set allows users to model hierarchical data structures. When you create a code list in a hierarchical reference data set, the code list inherits the hierarchical structure definition. In the code list, you can arrange the code values into levels to create hierarchies.
What symbols define a comment line in Verilog?
There are two ways to write comments in Verilog.
- A single line comment starts with // and tells Verilog compiler to treat everything after this point to the end of the line as a comment.
- A multiple-line comment starts with /* and ends with */ and cannot be nested.
What characters does Verilog allow in an identifier?
Identifiers must begin with an alphabetic character or the underscore character (a-z A-Z _ )
What is a Verilog code?
Verilog, standardized as IEEE 1364, is a hardware description language (HDL) used to model electronic systems. It is most commonly used in the design and verification of digital circuits at the register-transfer level of abstraction. Since then, Verilog is officially part of the SystemVerilog language.
What is UDP in Verilog?
Verilog provides the ability to define User-Defined Primitives ( UDP ). These primitives are self-contained and do not instantiate other modules or primitives. UDPs are instantiated exactly like gate-level primitives. There are two types of UDPs: combinational and sequential.
How do I import a package into Systemverilog?
All packages have to be enclosed within the package and endpackage keywords. The package shown above can be imported into other modules and class scopes so that items defined in it can be re-used. This is done using the keyword import followed by the scope resolution operator :: that then specifies what to import.
Which operation has highest precedence in Verilog?
Operator Precedence in Verilog
| Precedence | Operators | Operator Symbols |
|---|---|---|
| Highest | Unary Multiply Divide, Modulus | + – ! ~ * / \% |
| Add Subtract Shift | + – << >> | |
| Relational Equality | < <= > >= == !== === !=== | |
| Reduction Logical | & ~& ^ ^~ | ~| && || |
What is assign in Verilog?
Assign statements are used to drive values on the net. This concept is realized by the assign statement where any wire or other similar wire (data-types) can be driven continuously with a value. The value can either be a constant or an expression comprising of a group of signals.
What is instantiation in Verilog?
The process of creating objects from a module template is called instantiation, and the objects are called instances. Each instance is a complete, independent and concurrently active copy of a module. A module can be instantiated in another module thus creating hierarchy.
What is a hierarchical path name in Verilog?
Every identifier in Verilog has a unique hierarchical path name, where each module instance, task, function or named begin end or fork join block defines a new level or scope.
What is the scope of Verilog?
Verilog defines a new scope for modules, functions, tasks, named blocks and generate blocks. module tb; reg signal; reg signal; task display(); reg signal = 1; $display(“signal = \%0b”, signal); endtask endmodule An identifier, like a signal name, can be used to declare only one type of item in a given scope.
What is a module in Verilog?
A module is a block of Verilog code that implements certain functionality. Modules can be embedded within other modules, and a higher level module can communicate with its lower-level modules using their input and output ports.
What is the root of a hierarchical structure?
A hierarchical structure is formed when modules can be instantiated inside one another, and hence the top-level module is called the root. Since each lower module instantiates within a given module, which should have different identifier names, there will not be any ambiguity in accessing signals.