VHDL Interview Questions and Answers, VHDL Interview Questions and Answers Freshers, VHDL Interview Questions and Answers, VHDL Interview Questions

Before getting on to the VHDL interview questions, the student must know that the VHDL is a continuously varying field which needs the students as well as professionals to upgrade their skills with the new features and knowledge, to get fit for the jobs associated with VHDL. This post related to VHDL Interview Questions and Answers, VHDL Interview Questions and Answers Freshers, VHDL Interview Questions and Answers, VHDL Interview Questions will help you let out find all the solutions that are frequently asked in you upcoming VHDL interview.

Over thousands of vacancies available for the VHDL developers, experts must be acquaintance with all the component of VHDL technologies. This is necessary for the students in order to have in-depth knowledge of the subject so that they can have best employment opportunities in the future. Knowing every little detail about VHDL is the best approach to solve the problems linked with problem.

APTRON has spent hours and hours in researching about the VHDL Interview Questions and Answers, VHDL Interview Questions and Answers Freshers, VHDL Interview Questions and Answers, VHDL Interview Questions that you might encounter in your upcoming interview.  All these questions will alone help you to crack the interview and make you the best among all your competitors.

First of all, let us tell you about how the VHDL technology is evolving in today’s world and how demanding it is in the upcoming years. In fact, according to one study, most of the companies and businesses have moved to the VHDL. Now, you cannot predict how huge the future is going to be for the people experienced in the related technologies.

Hence, if you are looking for boosting up your profile and securing your future, VHDL will help you in reaching the zenith of your career. Apart from this, you would also have a lot of opportunities as a fresher.

These questions alone are omnipotent. Read and re-read the questions and their solutions to get accustomed to what you will be asked in the interview. These VHDL interview questions and answers will also help you on your way to mastering the skills and will take you to the giant world where worldwide and local businesses, huge or medium, are picking up the best and quality VHDL professionals.

This ultimate list of best VHDL interview questions will ride you through the quick knowledge of the subject and topics like VHDL Architecture, Need, Scope, Use and History of VLSI, Chip Design Process. This VHDL interview questions and answers can be your next gateway to your next job as a VHDL expert.

These are very Basic VHDL Interview Questions and Answers for freshers and experienced both.

Q1: What Is Vhdl?
A1: VHDL stands for “VHSIC Hardware Description Language.” VHSIC, in turn, stands for “Very High Speed Integrated Circuit,” which was a U.S. Department of Defense program.

Q2: What Are Generics?
A2: Generics are a way to provide static information to the VHDL program. Immediately after writing entity name, we will mention the generics, this generics will provide the data for entire program. Generics basically allow a design entity to be described so that,for each use of that component,its structure and behavior can be changed by generic values.In general they are used to construct parameterized hardware components.Generics can be of any type.but mostly we will give the timing details there.

E.g. :- generic ( width : integer := 7 );

Generic is a great asset when you use your design at many places with slight change in the register sizes,input sizes etc. But if the design is very unique then,you need not have generic parameters. Also, Generic’s are synthesizable.

Q3: Are Verilog/vhdl Concurrent Or Sequential Language In Nature?
A3: Verilog and VHDL both are concurrent languages. Any hardware descriptive language is concurrent in nature.

Q4: What Is A D-latch?
A4: D latch is a device it simply transfers data from input to output when the enable is activated.its used for the forming of d flip flops.

Q5: Which Is The Default Delay In Vhdl?
A5: delta delay.

Q6: What Is An Alias And Write Its Syntax?
A6: Alias is an alternative name assigned to part of an object. alias alias_name : subtype isname

Q7: List Out The Objects Of Vhdl?
A7: Signal, Variable, Constant.

Q8: List Out The Levels Of Abstractions In Vhdl?
A8: Data flow level, Structural Level, Behavioral Level.

Q9: What Do We Need To Generate Hardware From Vhdl Model?
A9: We need following tools

  • Simulation tool.
  • Synthesis tool.
  • Implementation tool.

Q10: How The Signal Acts Within A Process And Outside The Process?
A10: Signal assignment is concurrent outside the process and sequential within a process.

Q11: What can be the various uses of VHDL ?
A11: The VHDL language can be used for several goals like –

i) To synthesize digital circuits
ii) To verify and validate digital designs
iii) To generate test vectors to test circuits
iv) To simulate circuits

Q12: What is Synthesis?
A12: Synthesis represents the transformation of an abstract description into a more detailed descrition. In general, the term “synthesis” is used for the automated transformation of RT level descriptions into gate level representations. This transformation is mainly influenced by the set of basic cells that is available in the target technology. While simple operations like comparisons and either/or decisions are easily mapped to boolean functions, more complex constructs like mathematical operators are mapped to a tool specific macro cell library first. This means that a number of adder, multiplier, etc. architectures are known to the synthesis tool and these designs are treated as if they were designed by the user.

Q13: What is the difference between Concurrent & Sequential Statements ?
A13: Concurrent statements define interconnected processes and blocks that together describe a design’s overall behavior or structure. They can be grouped using block statement. Groups of blocks can also be partitioned into other blocks. At the same level, a VHDL component can be connected to define signals within the blocks It is a reference to an entity A process can be a single signal assignment statement or a series of sequential statements (SS) Within a process, procedures and functions can partition the sequential statements

Q14: What are VHDL Subtypes ?
A14: VHDL subtypes are used to constrain defined types. Constraints take the form of range constraints or index constraints. However, a subtype may include the entire range of the base type. Assignments made to objects that are out of the subtype range generate an error at run time. The syntax and an example of a subtype declaration is shown below :-


Q15: Mention what is the difference between the TTL chips and CMOS chips?

TTL Chips CMOS Chips
  • TTL chips for transistor transistor logic. It uses two Bi-polar Junction Transistors in the design of each logic gate
  • TTL chips can consist of a substantial number of parts like resistors
  • TTLS chip consumes lot more power especially at rest. A single gate in TTL chip consumes about mW of power
  • TTL chips can be used in computers
  • CMOS stands for Complementary Metal Oxide Semi-conductor. It is also an integrated chip but used field effect transistors in the design
  • CMOS has greater density for logic gates. In a CMOS chip, single logic gate can comprise of as little as two FETs
  • CMOS chips consume less power. A single CMOS chip consume about 10nW of power
  • CMOS chip is used in Mobile phones

Q16: Explain what is a sequential circuit?
A16: A sequential circuit is a circuit which is created by logic gates such that the required logic at the output depends not only on the current input logic conditions, but also on the sequences past inputs and outputs.

Q17: In Verilog code what does “timescale 1 ns/ 1 ps” signifies?
A17: In Verilog code, the unit of time is 1 ns and the accuracy/precision will be upto 1ps.

Q18: Explain what is the depletion region?
A18: When positive voltage is transmitted across Gate, it causes the free holes (positive charge) to be pushed back or repelled from the region of the substrate under the Gate. When these holes are pushed down the substrate, they leave behind a carrier depletion region.

Q19: Explain what is the use of defpararm?
A19: With the keyword defparam, parameter values can be configured in any module instance in the design.

Q20: Explain what is multiplexer?
A20: A multiplexer is a combination circuit which selects one of the many input signals and direct to the only output.

VHDL Conclusion Interview FAQs

We know the list of VHDL Interview Questions and Answers, VHDL Interview Questions and Answers Freshers, VHDL Interview Questions and Answers, VHDL Interview Questions is overwhelming but the advantages of reading all the questions will maximize your potential and help you crack the interview. The surprising fact is that this VHDL interview questions and answers post covers all the basic of the VHDL technology and you have to check out the FAQs of different components of VHDL too.

However, you will be asked with the questions in the interview related to the above mentioned questions. Preparing and understanding all the concept of VHDL technology will help you strengthen the other little information around the topic.

After preparing these interview questions, we recommend you to go for a mock interview before facing the real one. You can take the help of your friend or a VHDL expert to find the loop holes in your skills and knowledge. Moreover, this will also allow you in practicing and improving the communication skill which plays a vital role in getting placed and grabbing high salaries.

Remember, in the interview, the company or the business or you can say the examiner often checks your basic knowledge of the subject. If your basics is covered and strengthened, you can have the job of your dream. The industry experts understand that if the foundation of the student is already made up, it is easy for the company to educate the employ towards advance skills. If there are no basics, there is no meaning of having learnt the subject.

Therefore, it’s never too late to edge all the basics of any technology. If you think that you’ve not acquired the enough skills, you can join our upcoming batch of VHDL Training in Noida. We are one of the best institute for VHDL in noida which provide advance learning in the field of VHDL Course. We’ve highly qualified professionals working with us and promise top quality education to the students.

We hope that you enjoyed reading VHDL Interview Questions and Answers, VHDL Interview Questions and Answers Freshers, VHDL Interview Questions and Answers, VHDL Interview Questions and all the FAQs associated with the interview. Do not forget to revise all the VHDL interview questions and answers before going for the VHDL interview. In addition to this, if you’ve any doubt or query associated with VHDL, you can contact us anytime. We will be happy to help you out at our earliest convenience. At last, we wish you all the best for your upcoming interview on VHDL Technology.