VLSI Interview Questions And Answers Guide.
Global Guideline. http://www.globalguideline.com/
VLSI Interview Questions And Answers
VLSI Job Interview Preparation Guide.
Question # 1 Have you studied pipelining? List the 5 stages of a 5 stage pipeline. Assuming 1 clock per stage, what is the latency of an instruction in a 5 stage machine? What is the throughput of this machine?
Answer:1.Instruction fetch 2.decode instruction and read register files 3.execute 4.data to access from memory 5.write back throughput is the total amount of work done in a given time, Read More Answers.
Question # 2 Explain How many bit combinations are there in a byte?
Answer:1 byte means 8 bits so 256 com Read More Answers.
Question # 3 Suppose For a single computer processor computer system, what is the purpose of a processor cache and describe its operation?
Answer:the purpose of cache is to reduce the average time to access the main memory, the operation is like that when the CPU wants to access the data, it first check the cache, if an entry can be found with a tag matching that of desired data, CPU gets the data from cache directly, otherwise, the data will be copied into cache for next access. Read More Answers.
Question # 4 Do you know MESI?
Answer:Is a widely used cache coherency and memory coherence protocol introduced by Intel. Modified Exclusive Shared Invalid are the protocol States. M means value has been modified from main memory and the cache is required to write the data back to main memory, before permitting any other read of the main memory state. (ITS DIRTY) E IS CLEAN: Value Match with main memory S Cache may be stored in other caches of the machine I Invalid Read More Answers.
Question # 5 Copyright © http://www.GlobalGuideline.COM
Page 2/7
VLSI Interview Questions And Answers
What are the main issues associated with multiprocessor caches and how might you solve them?
Answer:issue : Cache coherency or Data coherency. The problem is all the processors cache should have exactly the same shared data (cohenrent data). and there are races possible with multiprocessors. possible solution: use one central cache controller which will get all the read/write requests from all the processors and peripherals so that it can make sure there are no races and cache coherency is maintained. Read More Answers.
Question # 6 What types of high speed CMOS circuits have you designed?
Answer:Dynamic CMOS ckts and high speed multipliers using BOOTh/Mod-Booth algorithm. Read More Answers.
Question # 7 What products have you designed which have entered high volume production?
Answer: jigs and fixtures Read More Answers.
Question # 8 If not into production, how far did you follow the design and why did not you see it into production?
Answer:Design is a general term,applicable in every field of engineering.however production is termed as to follow up the steps after design to make product available in the market. Read More Answers.
Question # 9 What is the most complicated/valuable program you written in C/C++?
Answer:Matrix Read More Answers.
Question # 10 Explain the difference between write through and write back cache?
Answer:Write Through. After writing in cache memory, main memory is updated too inmediatly to mantain reliability Write Back After writing in cache memory a flag bit called dirty bit is set. When this value need to be replaced that bit is check, if it is set then the value is taken to main memory Read More Answers.
Question # 11 What is the term snooping?
Answer:Let's take an example of different processors(along with their independent caches) sharing the same memory system. Now if this memory is a Read-Write memory and let's say that one of the processors writes to this memory after some data computation, all the processors need to update their individual cache copies of the now modified memory. To do this the concept of snooping is implemented. cache snooping is the means by which each cache constantly monitors/detects the bus for any write to a memory location and if a write is found, it invalidates it current copy of cached memory data and copies the new content over. Copyright © http://www.GlobalGuideline.COM
Page 3/7
VLSI Interview Questions And Answers
Read More Answers.
Question # 12 Describe a finite state machine that will detect three consecutive coin tosses (of one coin) that results in heads?
Answer:State machine to detect 3 consecutive heads appearing in multiple tosses; state 1 : initial state As long as the toss results in TAIL , in this state If the toss results in HEAD go to state 2 state 2 : HEAD1 resulted in the next toss , If TAIL is resulted go to the initial state1 . If HEAD is resulted go to state3. state3 : HEAD2 is resulted in the next toss , If TAIL is resulted go to the initial state1 . If HEAD is resulted go to state4. state4 : HEAD3 is resulted and this is the final state As long as the HEAD results in each next toss be in state 4. If any toss results in TAIL go to initial state1 Read More Answers.
Question # 13 In what cases do you need to double clock a signal before presenting it to a synchronous state machine?
Answer:if the input signal is asynchronous with the clock (state machine clock), then you need to double clock the same signal to synchronize with the state machine clock. Read More Answers.
Question # 14 You have a driver that drives a long signal & connects to an input device. At the input device there is either overshoot, undershoot or signal threshold violations, what can be done to correct this problem?
Answer:This is a signal integrity question for board designers. there are two types of termination schemes viz. series and parallel termination. series termination is where a resistor of small value ( rule of thumb 1/2 of characteristic impedance of the trace ) placed near the source ( near driver). the parallel termination is a combination of two resister ( rule of thumb twice the char. impedance f the trace) placed near the destination ( input) where one resistor connects the signal trace to the VCC and other connects to the GNd. Read More Answers.
Question # 15 What is VHDL and/or Verilog?
Answer:vhdl is very high speep integrated chips hardware descripted language and verilog is to verify logic Read More Answers.
Question # 16 What are the total number of lines written by you in C/C++? What compiler was used?
Answer:here we use the lines depends on the programme.But we have 65536 lines which are available in it Read More Answers.
Question # 17 What is the difference between = and == in C?
Answer:'=' in c is the assignment opperator.whereas '==' is the logical equality operator. Copyright © http://www.GlobalGuideline.COM
Page 4/7
VLSI Interview Questions And Answers
Read More Answers.
Copyright © http://www.GlobalGuideline.COM
Page 5/7
Computer Programming Most Popular Interview Topics.
1 : PHP Frequently Asked Interview Questions and Answers Guide. 2 : C++ Programming Frequently Asked Interview Questions and Answers Guide. 3 : C Programming Frequently Asked Interview Questions and Answers Guide. 4 : Software engineering Frequently Asked Interview Questions and Answers Guide. 5 : Cobol Frequently Asked Interview Questions and Answers Guide. 6 : Visual Basic (VB) Frequently Asked Interview Questions and Answers Guide. 7 : OOP Frequently Asked Interview Questions and Answers Guide. 8 : Perl Programming Frequently Asked Interview Questions and Answers Guide. 9 : XML Frequently Asked Interview Questions and Answers Guide. 10 : Socket Programming Frequently Asked Interview Questions and Answers Guide.
About Global Guideline.
Global Guideline is a platform to develop your own skills with thousands of job interview questions and web tutorials for fresher's and experienced candidates. These interview questions and web tutorials will help you strengthen your technical skills, prepare for the interviews and quickly revise the concepts. Global Guideline invite you to unlock your potentials with thousands of Interview Questions with Answers or begin a tutorial right away, such as HTML, XML, XSLT, Cascading Style Sheet (CSS), Search Engine Optimization (SEO), JavaScript, Structure Query Language (SQL), Database Articles, Web Hosting Guide and much more. Learn the most common technologies Interview Questions and Answers. We will help you to explore the resources of the World Wide Web and develop your own skills from the basics to the advanced. Here you will learn anything quite easily and you will really enjoy while learning. Global Guideline will help you to become a professional and Expert, well prepared for the future.
* This PDF was generated from http://www.GlobalGuideline.com at June 19th, 2013 * If any answer or question is incorrect or inappropriate or you have correct answer or you found any problem in this document then don't hesitate feel free and e-mail us we will fix it. You can follow us on FaceBook for latest Jobs, Updates and other interviews material. www.facebook.com/InterviewQuestionsAnswers Follow us on Twitter for latest Jobs and interview preparation guides http://twitter.com/InterviewGuide
Best Of Luck. Global Guideline Team http://www.globalguideline.com
[email protected]
