Difference Between Verilog and VHDL (With Table)

Hardware Description Language (HDL) is a computer language used to describe electronic circuit structures. It is similar to conventional programming languages like C. There are many HDL used these days and every language has its own set of rules and advantages. Verilog and VHDL are two different hardware description languages that are most commonly used these days.

Verilog vs VHDL

The difference between Verilog and VHDL is that Verilog is a comparatively newer language, which is used to model electronic systems and it is based on C language, on the other hand, VHDL is an older language than Verilog and it is based on Ada and Pascal languages.

Verilog is a hardware description language. It is used to define electronic circuits and systems like microprocessors and flip-flops. It is based on the C language hence it is easier to learn for the people knowing C. It is a compact language that does its function effectively.

VHDL is a short form for Very High-Speed Integrated Circuit Hardware Description Language. It is used to describe hardware and many more like integrated circuits. It is an older language and it is based on Ada and Pascal languages. Its projects can be used as a multipurpose program as one program can be used again with some minor changes.

Comparison Table Between Verilog and VHDL

Parameters of ComparisonVerilogVHDL
Definition Verilog is a hardware description language used for modelling electronic systems.VHDL is a hardware description language used to describe digital and mixed-signal systems.
Introduced Verilog is a newer language as it was introduced in 1984.VHDL is an older language as it was introduced in 1980.
Language It is based on the C language.It is based on Ada and Pascal languages.
Difficulty Verilog is easier to learn.VHDL is comparatively harder to learn.
AlphabetsVerilog is Case sensitive.VHDL is case insensitive.

What is Verilog?

Verilog is a hardware description language introduced in 1984. It is similar to the C language. It is used to model electronic circuits and systems. It is using many data types that are predefined. It is easier to learn and people with background knowledge of C do not find any difficulty in learning this language.

It is a compact language so the programmer has to write fewer lines to execute the task. It is used for verification by the method of simulation for different tasks like fault grading, testability analysis, timing analysis, and logic synthesis. All these electronic systems work is done by writing this language in textual format.

It is a weakly typed language. It is a case-sensitive language which means it will treat “bat” and “BAT” as two different words. All the codes in this language start with the word “module” and stop with the word “endmodule” and similar to the C language, the line ends with a semicolon.

It developed with time since 1995, now it is merged with the system Verilog. With constant up-gradation, it gets many features but still, it lacks library management. Overall it is convenient for a new generation to use for hardware modeling.

What is VHDL?

VHDL is also a hardware description language which is also known as Very High-Speed Integrated Circuit Hardware Description Language. It is used to model the working of digital systems. It was introduced in the 1980s and was developed by the U.S Department of Defence. Then after 1987, it is standardized by the Institute of Electrical and Electronics Engineers also known as IEEE.

It is based on Ada and Pascal languages and it also has some extra features that these languages lack. It functions in two modes, the first one is Statement execution in which it evaluates the triggered statements. And the latter one is, Event processing in which it processes the events in the queue.

It also has Boolean operators like nor and nand, which helps VHDL to represent operations precisely. It is a case insensitive language that means it treat upper case alphabets and lower case alphabets as the same data and Its projects are portable and multipurpose in many ways.

As it is based on Ada and Pascal languages it is more difficult to learn because these languages are not that much popular among programmers. It is a strongly typed language that allows users to create some extra and complex data types.

Main Differences Between Verilog and VHDL

  1. The main difference between Verilog and VHDL is that Verilog is an HDL based on C language, on the other hand, VHDL is also an HDL but it is based on Ada and Pascal languages.
  2. Verilog was introduced in 1984 whereas VHDL was introduced in 1980 by the US Department of Defence.
  3. Verilog is a newer and case-sensitive language, on the other hand, VHDL is older and case insensitive language.
  4. As Verilog is based on a popular C language hence it is easier to learn but VHDL is difficult to learn as it is based on non-conventional languages.
  5. Verilog is used to model electronic systems and circuits like microprocessors and flip-flops whereas VHDL is used to describe digital and mixed signals like integrated circuits.

Conclusion

Hardware description languages are needed for this generation as most of the things around us are dependent on electronic systems and circuits. These languages made tasks easier and effective. Many languages can be used for this task, Verilog and VHDL are the two most popular languages among programmers.

Many same tasks can be performed using both languages but Verilog is a compact language hence needed fewer lines of code for completion of tasks whereas VHDL will require more long codes. Verilog is an easier language as it is based on C language on the other hand VHDL is difficult to learn as it is based on Ada and Pascal languages.

References

  1. https://ieeexplore.ieee.org/abstract/document/545676/
  2. https://trilobyte.com/pdf/golson_clark_snug16.pdf
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