VHDL, Verilog, and SystemVerilog

Introduction

These days, our world is filled with technology that is crucial for our everyday lives. From phones to laptops, they bring an aspect of our lives to another dimension. However, their technologies not only rely on software programming or design applications to work. Rather, they rely on complex hardware programming that enables them to systematically send messages or convert basic binary code to a digital format. Today, let’s dive into the basics of HDL (also known as “hardware description languages”).

There are three types of HDLs – VHDL, Verilog, and SystemVerilog. These languages are required to execute register-transfer-level (RTL) abstractions. RTL is a type of design abstraction that allows information from one register to another in some other type of symbolic code. However, this is a conversation for another time.

VHDL

Let’s start with VHDL! VHDL is often considered as “better than Verilog.” Preceding Verilog, VHDL is more verbose and complex, meaning it will be hard to learn. However, once learned, it will be much easier to learn Verilog. Furthermore, VHDL is often taken after the Ada programming language (an object-oriented high-level programming language) as they have followed somewhat of a similar concept and syntax. Thus, it makes VHDL more ancient and more strongly typed, almost written in a self-documenting code. Hence, this language is more commonly used for aerospace and defense technology. 

Verilog

On the other hand, Verilog is considered to be easy. It is rumored that Verilog was designed after features found in the HiLo (ancient HDL language) and C programming language. This gives its users a much easier way to understand and write than VHDL does. However, due to this fact, Verilog is weakly typed, where there are more rules and notations to look after to follow the C programming language type of structure. Hence, as Verilog is faster and easier to write, it is more frequently used in the semiconductor industry in order to simulate and model any systems used in circuits. 

SystemVerilog

Last but not least, SystemVerilog is often considered an advanced version of Verilog. It is both a hardware description and verification language, meaning that it is a universal language used to both design and implement electronic systems. This is drastically different from Verilog as it is a low-level language, where it only aims to describe hardware behavior rather than modeling and simulating complex electronic systems. Furthermore, SystemVerilog introduces object-oriented programming concepts that allow coders to reuse and organize their code better. Thus, this is also another commonly used language in the semiconductor and electronic design industry. Hence, SystemVerilog is often a more preferred type of language than Verilog or VHDL as it closely leans to the software side of the programming languages. 

Conclusion

At the end of the day, every language has its own benefits and flaws. Depending on the situation and context, these three languages help engineers creatively use them for specific System-on-a-Chip design (SoC) needs, and allow creativity and innovation to take place.