Synthesis and Physical Design Interview Questions: Question Set -5

Code: CYPR2Y102020PD

Introduction and Experiences

1. Self Introduction
2. Explain about the projects that you have worked on. (Type of work and tools used)

Synthesis

1. Explain about Synthesis flow and what happens at each stage. (Inputs required, elaboration, generic stage, mapping and optimization stages)
2. Explain about Synthesis Inputs. 
3. Differentiate between Logical and Physical Synthesis. (QoR impact between them)
4. Wire load model(WLM), Mode, Types of trees
5. Delay Calculation in WLM method. (Fanout based delay calculation)

 

Place and Route

1. What are Inputs for PnR and Initial Checks need to be done?
2. How to check for uniqueness of Netlist?
3. Explain stages in PnR.
4. Explain about useful skew and how it impacts the design.
5. How do we achieve a better insertion delay?
6. Explain about the CTS issues that you solved.
7. Explain Physical Cells at the transistor level.
8. Explain UPF, power domains, supply sets, isolation cells, retention registers.
9. Feedthru insertion procedure and minimizing them. How you did Partitioning and improved partition related size, ports creation, Congestion.

RTL

1. RTL Code for synchronous rst and asynchronous rst. (How do we write always block for this?)
2. How do you write RTL code for FSM? (Explain about the number of always blocks required and significance of each one)
3. Write RTL code for the traffic light system.

SignOff

1. Explain about the LEC procedure and issues faced and solved with respect to non-equivalent points.
2. How do we fix Setup and Hold time violations?
3. Explain about Dynamic and Leakage Power Consumption and methods to reduce them.
4. If the chip is fabricated and hold violation exists. So what will you do? (other than saying that chip won't work)
5. Scripting related to finding empty modules, Unix commands.

Post Credit: 

These questions are shared by one of our active group members. Thanks a lot for your contribution!!!

Basic Dos and Don'ts for Freshers in VLSI Interview

Hello Guys,

As you all know that the entry in the VLSI Industry is not easy for freshers, and it becomes more difficult especially if you don't belong from tier-1 institutes of India. But keep good hopes always with you, people who are eligible, definitely get chance. So here important thing which I want to tell you is If you get an interview call, convert this rare opportunity into the offer later. And for freshers, believe me, what matters most is to start the first job irrespective of a big or small company. Once you are in the industry and working well, you can switch any company later. 

So, here are some Dos and Don'ts which a fresher's must follow during the interview. Never take too much pressure on the interview, but at the same time don't be ignorant. Your result will be determined on the basis of what you answer in the interview not what you know and understand. So being presentable and prepared matters most. 

Dos:

1. Choose the best environment:

If the interview is telephonic, you must choose a place where the network of your mobile is good, avoid any surrounding noise and use the best quality earphone. In a telephonic interview, your audio quality is a very important factor during the call. In case of the video call, make sure for the good bandwidth and audio/microphone connectivity and join the virtual meeting room on time. 

2. Be honest with your CV:

In fresher's interview, interviewers generally ask a few questions related to your CV only. So you must be aware whatever you have written in your CV and proper justification should be there if any questions arise from your CV. Be prepared and honest with your answers.

3. Think before answer:

Listen to the interviewer very carefully, take a small pause before answering if required and then answer. Many time your next question will come based on your current answer, so try to drive the interviewer in the right direction. 

4. Keep Answers short

Always try to keep your answer shorts, more you elaborate, more chances of mistakes. And some time interviewers are not interested to listen to the thing which he has not asked.

5. Answer to the point only

Always try to give the answer to the point. If you are not aware of the question, It's better to say Sorry and move to the next question instead of irrelevant answers. 

6. Be specific

If any question comes from your project/thesis be very specific, and tell them the exact problem/issue and how you solved that instead of giving a long theoretical answer. In the interview, your practical experience matters most than the general approach. But If any question comes to test your theoretical understanding then you may use a general concept for the explanation.

Don'ts:

1. Never rush to answer:

Sometimes a very well known question comes for which candidate is well prepared, so they start answering even before the interviewer complete the question. Avoid this thing, and wait for the completion of question. There may be some twist in the last part of the question.

2. Avoid criticism:

Sometimes questions come, like why do you want to join/work in a particular area, then never criticise the other domain, Just show your interest for which you have appeared in the interview 

3. Avoid exaggeration:

Never exaggerate any topic while answering a question, the best way is keep your answer short and to the point only.

Thank you!