HARRY POTTER AND MYSTERY OF CORE JOBS

It is rather mystique to discover the correct path and even mysterious to find a mentor - specially when you're preparing for a core job!

My preparation fueled on oiling my ears to hear every advice my seniors were giving and eavesdropping on my peers' preparation strategies. The following is a fine collection of all the resources that are sufficient to crack any CORE job :


First up, we need to know the terra-incognito, the uncharted and unmastered lands. All the places we need to be - to gather the arsenal to champion placements.



Following is the list of all the subjects we need to be proficient ( at-least familiar) in:

1.Digital Electronics 📱
2.Analog Electronics 

3.Computer Architecture and Microprocessor (COA,8085/86/ARM)💻
4.Hardware language ( Verilog/VHDL ) ䷔
5.Miscellaneous ( Projects, Aptitude, scripting languages- Perl, python, LINUX, etc ) ❓

After knowing the places we need to be, let's start filling in the details on the map: 

There are different domains of jobs for which you can apply - Frontend Design Engineer, Verification Engineer, Physical Design Engineer, Software Engineer, Embedded Software Engineer, etc.

Check out this ARTICLE to get the idea of all the types of jobs a CORE VLSI engineer can choose from : 

To get some sense check of the fields, let's check out some career portals and read their Job Description:
1. GOOGLE HARDWARE OPENINGS 
2. NVIDIA OPENINGS
3. QUALCOMM OPENINGS
4. TEXAS INSTRUMENTS

I would suggest everyone reading this post to go check out different job openings. I agree these openings at senior position won't be making much sense but it is good enough to gauge what is expected from a candidate for these roles.

This placement preparation will cover all the possible openings as you'll be covering all the topics which are stated as pre-requisites :

DIGITAL ELECTRONICS

Books: Anand kumarHarris and Harris and kang 

1. Basics of Digital Circuits and System
  
Topics to Cover :
 Number Systems, Binary Codes, Boolean Algebra, Laws,
 Combinational Circuits Design, K-Maps, Comparators, Encoder, Decoder, MUX etc,
 Sequential Circuit Design, Flipflops, Counters, Shift Registers, Types of ADCs and DACs).

Resources:
 *Anand Kumar for theory/ standard questions
 *This Youtube playlist: link [you can also check out this channel's other content regarding FPGAs]
 *
You can refer the following link for ready-reference Notes: 
https://gatenotes.in/gate-ece-notes.php

2. Counter Questions with different duty_cycle and count :
* Durga sir's video explains in detail about clock dividing circuits - link 
* Refer to this 
pdf
* You need to do both Synchronous as well as Asynchronous. (Please refer to Anand Kumar for developing good understanding).

3. FSM (Read Anand Kumar and above links) : Companies can ask you to write code for designing FSM. Be prepared for that. You should be thorough with the concepts. Anand Kumar is good enough to understand the concepts. You just need to practice the questions of the PDF attached below containing FAQs. These 2 resources are more than enough to sit for any interview/test.

4. Static Timing Analysis: This is one of the favorite topics for interview and you are expected to be familiar with concepts of setup and hold time, Glitches, Hazard and Metastability along with ways to mitigate them.
Resources:
STA - This is hands down THE most exhaustive resource to cover STA. The more you know the better your chances are but try to cover at least first 5 chapters. (Chapter-2 and 3 being the MOST important ones). First you can check out this video series by Yash, this will give you a good kick start. 
Metastability : Kang also covers this in-detail. You can read the last chapters of Kang to get more information.
Synchronisers : This blog is sufficient and explains the concept very easily.

5. Hazards and Gltiches: As discussed above this is a very common topic. This is fairly easy to grasp and the mentioned resources are more than enough. The interviewer would focus on  -What? Why? How to mitigate? 
So you should paint a picture in your mind in the same order!
Resources:
link2 : First read this article and then follow the below PDF for crystal clear understanding
l
ink1 : This is the PDF mentioned above

6. FIFO depth Calculation: This is clubbed with microprocessor questions and is again a very important and frequently asked topic. Focus should be on understanding WHAT? WHY? HOW TO MITIGATE?
The mentioned cases are the only possible cases that an interviewer would cover so be thorough with the PDF and you'll be easily sailing through the tides of questions. 

7. Logic Family: Cover from KANG.  

8. Semiconductor memories: This is a SUPER important topic. 
   -RAM(SRAM and DRAM)
   -ROM
   -FLASH(Basic)
    You should be mindful about the differences between DRAM and SRAM. Their operational cycles. 
   Resources:
1. Read Kang very thoroughly. Solve the book back questions because they are directly asked in interviews. 
2. You can also refer to these lectures - NPTEL Lectures (Lec : 32-36)


Now comes the MOSTTTT VITAL asset of your preparation. This PDF single handedly contains 90% questions your interviewer is going to ask you: GOD_SENT_PDF


Honorary Mentions and Hall Of Fame resources: 
PRACTICE QUESTIONS : Should refer once the above is done!
*
http://asic.co.in/Index_files/Digital_interview_questions2.htm  [direct questions from this site has been observed in past years]
*digi_que
*https://www.allaboutcircuits.com/worksheets/counters/
*https://www.electronics-tutorials.ws/

ANALOG ELECTRONICS

Book: Sedra&SmithRazavi

Most of the companies come for Digital Roles. They are restricted to testing CMOS for digital logic designs. Only TI-Analog role, STM, Synopsys- for RAM design role would test you heavily on Analog part. Most of the other companies focus more on Digital Electronics. Ansys being an exception also asks about Signal-Systems, Python Programming, Control System, etc. Mostly Analog questions are preliminary and used in written/ on-screen testing rounds. 
You should have a basic understanding of MOSFET and RC circuits because direction of interview depend upon your interviewer's profile and if she comes from an Analog background - you would not want to surround yourself with awkward silence. 

Topics to Cover:
Texas Instruments tests you heavily on conceptual network analysis problems:
 * Problems with inductors, diodes, connection of 2 capacitors with unequal initial charge
 * Opamps in networks
 * Frequency domain transfer function and frequency analysis
 * Concepts of series and parallel resonance in RLC circuits
 * D/A converter using R2R ladder
 * LC oscillation, 3db frequency from pole zero plot
 * Questions on shorting a non ideal current source with a non ideal voltage source
 * Finding Vce in a DC biased BJT and a question on combination of two CMOS.

Keep this in mind that you are expected to solve the question intuitively not just numerically with different inputs and understand the working of circuit. The best resource to get great in Analog Electronics is to start following the video lectures of masters of the subject - Behzad Razavi, Ali Hajimiri, NPTEL lectures. Start as early as possible so that you have ample time to grasp the concept and fall in love with the subjects. 

Resources:

1. RC circuits : This is the base for all the RLC circuit questions. You should focus on developing intuition about the circuits as interviewer will ask you to draw graphs and characteristics of a setup.
Some good resources to follow include:

[Please understand that you don't need to follow
ALL of the following playlists, just pick one you feel most connected with (I felt most connected with Razavi sir's playlist) and try to ruminate the same instead of trying to finish all the playlists]

*Please start from here if you are new or find yourself struggling with the basic concepts of electronics: BASIC ELECTRONICS LECTURES BY BEHZAD RAZAVI 
* NPTEL Lectures -  
link (114-148) 
Fundamentals of Electric Circuits: Alexander, Sadiku : Try to read this while following any of the lecture series and solve as much as you can of the book back exercises. Alternatively you can also pick previous year GATE question papers to solve problems (TOPIC WISE PROBLEMS).
* You can also opt for GATE paid courses if you feel the need of more structured and personal classroom connect. They provide well structured course with a lot of quality questions. You can also share the fees among your group of friends to cut the overall cost.
* Some other good Youtube playlists are : Playlist-1  Playlist-2 [
Language used - Hindi ]

2. Basic Network: This is similar to the above point and can be covered from any of the above mentioned resources. 
3. Opamp basics : Questions on virtual ground and named circuits are very important.
* Sedra and Smith is the best resource for learning about Op-Amp. Pay attention to the end pages of the book (Glossary section), to cover named circuits and special cases. 

* You can also follow the mentioned playlist - link(98-110)

4. Basics of Analog: You can follow any of the mentioned playlist if you have enough time. This is the BESTESTEST video lecture series I have ever come across to learn Electronics. Razavi sir has explained it so beautifully that even commerce student can make sense out of it. 
* Electronics 1 , Electronics 2 : Behzad Razavi sir's Youtube playlist. This playlist contains all the lectures in one place : RAZAVI ELECTRONICS
* I highly recommend solving Razavi sir's book's questions for practice and read theory to cover any knowledge gaps. 
* BJTs are not that important and asked only in TI's written rounds or if you're strictly targeting a job involving BJTs. Mostly, companies will focus on MOSFET based questions. If you have done the above playlist and solved questions from Razavi sir's book, you're a GOD already!

5. Current Mirror and Diff Amp
If you have done the above playlist, you have already perfected the craft. You can refer to Sedra and Smith or Behzad Razavi's book

6. Pole Zero Intution: This is a very interesting concept. This is already covered by Razavi sir in his playlist LINK
* But this playlist and the concept shared here are top notch: Fast Analytical Techniques

7. Negative feedback and oscillators: This is also covered in the above mentioned Razavi sir's playlist. This is an important topic. 

If the time permits, I would suggest you to practice the book back questions of Razavi along with the lectures.
If you find Razavi sir's lectures slow paced and need something with a faster pace without compromising with quality. You can also check this playlist out by Nagendra sir : NPTEL course

Note: I want to clarify what is meant by basics . For example you do current mirror understand basics don't start delving into wilson, widlar and types. Similarly Opamp understand basics don't go deep much into internal structure etc. in Diff amp no need to do Diffamp with active load. You would be digressing if you do that.

HDL LANGUAGES

Some companies like NXP, Cadence, etc ask HDL programming question to design circuits. VERILOG is the the industry de facto and hence, it is better to learn Verilog. In most colleges, we learn the VHDL. Although you'll be given flexibility in addressing questions with VHDL perspective but it's better to be industry prepared. There are a lot of quality free resources to learn VERILOG:

I preferred learning from book and by designing my digital circuits in Xilinx Vivado. I suggest picking up a research project with a professor to learn the language as you build a project. I referred Harris and Harris. This is the best book for VERILOG. This gives you design perspective as well as you can build mini projects while following the book.

If you prefer video lectures, you can refer the NPTEL course : NPTEL Course 
Some other useful websites to learn not only Verilog but also other industry relevant skills like SystemVerilog, UVM, SVA,  etc are: (Focus only on Verilog for now) 
Tutorialspoint
chipverify
asic-world

You can use the online simulator from eda playground or download Xilinx ISE/Vivado tool from getintopc.

Please refer to the following links for frequently asked interview questions. pdf1 and pdf2

COMPUTER ARCHITECTURE

Microprocessor and its applications and COA are one of the most crucial asset for any VLSI engineer. Having an in-depth knowledge and strong hold on the subject not only gives you a competitive edge over your peers but also helps you in your Job. Microprocessor and computer architecture are two subjects where you would want to shell out some money to learn from the best teacher - Bharat Acharya Education. I suggest sharing the course with your friends to cut the costs but I highly recommend these courses! You can also refer to the book - Gaonkar 8085/86. This is a standard book but I would suggest reading it on the sides with these courses.
Important topics include : Booth's Algo, Pipelining, Memory Organization, Input and output Muxing, Cache and Pipelining.

Free quality resources for the topic: 
Gate Smashers Youtube
Neso Academy

PROGRAMMING LANGUAGE

There is a very big misconception that CORE engineers don't need to learn programming languages. One significant portion of your job is to reduce the redundancy in tasks and automate the manual work, for these you need to be adept in at-least one scripting language and comfortable with LINUX environment if you want to cut short your learning curve post joining the company. These things (except C programming) are not a must but good to have skills.

For C Programming, I recommend : 
* ANSI C (E Balagurswamy) 
* LET US C
* If you prefer learning via Video Lectures feel free to pick up any Youtube Playlist and read the above books on the sides.

For Python I recommend :
Python book

You can also learn TCL and Perl Programming: The legacy scripts are written in Perl and TCL although new industry standards prefer Python but it is beneficial to know these.
If you have time you can also check out RegEx and GVIM editor. They're not strictly necessary but our productivity tools that also help you out in your other college assignments.  



PAST INTERVIEW EXPERIENCES

Following are some of the interview experiences you can refer to get a sense check about the companies before actual process: 

1. How to prepare for TI Analog Profile ?
2. Company wise List of Interview Questions

Mostly all the placement tests are taken from previous year GATE question papers. I highly recommend solving all the previous questions (only topics which concerns us). 

You can opt for any of the following books which has topic wise questions :

* https://amzn.to/3vj3mmY
https://amzn.to/3vnV39b
https://amzn.to/3WntaKD

MISCELLANEOUS ADVICE

Other than the above mentioned resources it would be beneficial to know about ASICs design flow, FPGAs, Good to have some exposure to Embedded system programming, Have research paper/ conference paper or Research projects on resume. 

You would also be interested in working with development boards and microcontrollers. This is not a strict requirement for on-campus placements but if you would want to apply off campus - this gives you edge over your competitors. These things give substance to interviewer to ask about, other than the usual technical questions.

Your resume can act as your wingman, it can save you from awkward silences and bring you luck in interviews. You should be very thorough with whatever you put in your resume. Placements are a function of Grit and Grind but there is a dependence over luck as well. 

At times, you will feel like the person you were teaching is getting placed before you. Your efforts are going in vain or the companies are finishing up. The times can get tough but you need to understand that hard-work never gets wasted. There are means beyond On-campus placements to get you placed. 
Rejections are part of life, you might get a few but each rejection should make you better. Your day will come soon and when it comes you will be the brightest star of the lot. Keep hustling, keep grinding! 





Credits:
1. Rachit's Blog
2. Tanuj's website
3. Riddhi's folder

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