Introduction to Verilog

Sources:

Editted and padded GPT content; if you prefer human sources: Verilog Data Types

This article focus on Verilog as a programming language, i.e. the simulation part is not covered.

Verilog is C-like with a few quirks tweaked for the HDL side of things.

Data Types

Verilog is a hardware description language used in digital circuit design. Here are the data types in Verilog:

1. **Wire**: A wire is a net that can be used to connect different components in a Verilog design. It is used to represent a physical wire in a circuit. Here is an example:

wire a, b, c;

2. **Reg**: A reg is a variable that is used to store values in a Verilog design. It is used to represent a register in a circuit. Here is an example:

reg [7:0] data;

This creates an 8-bit register called `data`.

3. **Integer**: An integer is a data type used to represent signed or unsigned values. Here is an example:

integer count = 0;

This creates an integer variable called `count` and initializes it to 0.

4. **Real**: A real is a data type used to represent floating-point values. Here is an example:

real pi = 3.14159;

This creates a real variable called `pi` and initializes it to 3.14159.

5. **Time**: A time is a data type used to represent time values in a Verilog simulation. Here is an example:

time delay = 10;

This creates a time variable called `delay` and initializes it to 10 time units.

6. **Parameter**: A parameter is a constant value that is used in a Verilog design. It is used to make the code more readable and easier to modify. Here is an example:

parameter WIDTH = 8;

This creates a parameter called `WIDTH` with a value of 8.

7. **Vector**: A vector is a data type used to represent multiple binary values. Here is an example:

reg [7:0] data;

This creates an 8-bit vector called `data`.

8. **Array**: An array is a data type used to represent multiple values of the same type. Here is an example:

 reg [7:0] mem [0:255];

This creates an array called `mem` with 256 elements, each of which is an 8-bit vector.

Array

In Verilog, arrays can be used to store multiple values of the same data type. The syntax for declaring an array in Verilog is as follows:

data_type array_name [size-1 : 0];

Here, `data_type` specifies the type of data that will be stored in the array (such as `reg`, `wire`, or `integer`).

Arrays in Verilog can be one-dimensional or multi-dimensional.

reg [7:0] my_array [3:0];

This declares an array called `my_array` that can store 4 elements, each of which is an 8-bit value.

reg [7:0] my_array [3:0][2:0];

This declares an array called `my_array` that can store 12 elements, each of which is an 8-bit value. The first dimension has 4 e