Electronic hardware designers describe the structure and behavior of system and circuit designs using HDLs (hardware description languages). This includes specialized programming languages such as Verilog, SystemVerilog, and VHDL. These are different from software programming languages. This is because they include a means of describing signal strengths and propagation time.
In today’s time, it is almost impossible to design a system on a chip for any consumer electronics item without an HDL. Each of the three HDLs has a distinct style that makes them different from each other. In this post, we are going to compare the three HDLs: Verilog, SystemVerilog, and VHDL.
Here you go with the details:
- VHDL
VHDL is a strongly typed language that is derived from the Ada programming language. Due to its language requirements, it is more verbose compared to Verilog. This type of strong typing requires additional coding to convert one data type to another.
VHDL is focused on semantics and designs that are easily portable from one tool to the other. A VHDL design depends on at least IEEE-Std 1164. Some depend on standard Math and Numeric packages as well.
- Verilog
In contrast to VHDL, Verilog is a weakly typed language. All data types available in Verilog are predefined in the language. In Verilog, all data types have a bit-level representation and the ones supported can be mixed freely.
Verilog has simulation semantics that is more ambiguous than the ones in VHDL. This provides more flexibility to designers in applying optimizations. However, it can also lead to race conditions if you fail to follow the required coding guidelines. With Verilog, you can achieve a design with different results on different vendors’ tools.
Verilog defines a set of basic system tasks within the language. It is because of this reason that Verilog users often run command-line or batch simulations by viewing waveforms from a simulation results database.
- SystemVerilog
SystemVerilog benefits from a Verilog extension which is known as Superlog and tenants of C++ and C programming languages. It extends Verilog by including a rich, user-defined type system. Not just that, but it also includes strong-typing capabilities in user-defined types.
SystemVerilog is a general-purpose language that provides capabilities for packaging and defining reusable functionality that is not included in the language. It also includes capabilities meant for assertion-based verification, interface packaging & abstraction, and testbench development.
From the above discussion, you can understand the difference between the three HDLs. All the three HDLs are used differently and in different situations by electronic hardware designers.
