ADVANCE QUESTIONS IN VLSI

Q-If not into production, how far did you follow the design and why did not you see it into

production?

Q-What was your role in the silicon evaluation/product ramp? What tools did you use?

Q-Process technology? What package was used and how did you model the package/system? What parasitic effects were considered?

Q-What types of I/O have you designed? What were their size? Speed? Configuration? Voltage requirements?

Q-What work have you done on full chip Clock and Power distribution? What process technology and budgets were used?

Q-What types of CMOS memories have you designed? What were their size? Speed?

Q-What are the total number of lines written by you in C/C++? What compiler was used?

VLSI INTERVIEWS QUESTIONS WITH ANSWERS

Q-WHAT IS THE DIFFERENCE BETWEEN TESTING AND VERIFICATION OF VLSI CIRCUIT?

ANS-Verification is a front end process and testing is a post

silicon process. verification is to verify the functionality of the design during the design cycle. Testing is find manufacturing faults.

    Re: What is  the difference between fifo and the memory?  Answer
# 1 
We can build FIFO using memory blocks (at a more granular level using a series of registers). One of the structure we can use for storing and retrieving data would be FIFO(First In First Out). Other structure could be a Stack which is a First In Last out kind of implementation. Similarity between them is that they are used of data storage.
Q- What is the most complicated/valuable program you written in C/C++? 

ANS-Animation of running train.

Q-What products have you designed which have entered high volume production?

ANS-jigs and fixtures

O-What types of high speed CMOS circuits have you designed?

ANS-Dynamic CMOS ckts and high speed multipliers using BOOTh/Mod-Booth algorithm.

Q-Are you familiar with VHDL and/or Verilog?

ANS-Verilog is Hardware Description Language VHDL : Very (High Speed Integrated Circuit) Hardware Description Language
Q- What is the difference between = and == in C?

ANS-= is used for assigning the value to a variable

for example int a=10; if a=5 printf("%d",a); else printf("%d",a);  output:5 in this program a value is assigned to 5 and 5 is printed.  whereas == is used to check the value of the variable for example int a=10; if a==5 printf("%d",++a); else printf("%d",a);  output:10  in this value of a is checked with 10 .If it is equal if  stmt is true and a is incrementd and printed. If it is not equal a value is printed.

1. What is D-FF?
2. What is the basic difference between Latches and Flip flops?
3. What is a multiplexer?
4. How can you convert an SR Flip-flop to a JK Flip-flop?
5. How can you convert an JK Flip-flop to a D Flip-flop?
6. What is Race-around problem? How can you rectify it?

7. Which semiconductor device is used as a voltage regulator and why?
8. Explain an ideal voltage source?
9. Explain zener breakdown and avalanche breakdown?
10. What are the different types of filters?
11. What is the need of filtering ideal response of filters and actual response of filters?
12. What is sampling theorem?
13. What is impulse response?
14. Explain the advantages and disadvantages of FIR filters compared to IIR counterparts.
15. What is CMRR?
16. Explain half-duplex and full-duplex communication?
17. Which range of signals is used for terrestrial transmission?
18. Why is there need for modulation?
19. Which type of modulation is used in TV transmission?
20. Why we use vestigial side band (VSB-C3F) transmission for picture?
21. When transmitting digital signals is it necessary to transmit some harmonics in addition to fundamental frequency?
22. For asynchronous transmission, is it necessary to supply some synchronizing pulses additionally or to supply or to supply start and stop bit?
23. BPFSK is more efficient than BFSK in presence of noise. Why?
24. What is meant by pre-emphasis and de-emphasis?
25. Explain 3 dB cutoff frequency? Why is it 3 dB, not 1 dB?
26. Explain ASCII, EBCDIC?

FIVE ELECTRONICS TOOLS

Five Electronics Tools You Might Not Know About

You've got your wire strippers and your soldering iron...now what? You probably know that there is a standard set of essential tools that you need on your electronics workbench. However, real tool junkies always want just the right tool for the job. Here are five electronics tools you may not know you were missing. These esoteric tools go a bit beyond the basics that everyone should have.

1) Resistor lead forming tool. Okay, you can bend your resistor leads by hand. We know. We all do it. But, resistor benders are fabulous for getting the leads bent squarely enough to go easily through the holes in your PCB or perf board. Silly? No, because it helps keep your board looking neat, and keeps the resistors from sticking too far above the board. If you are populating a circuit board with a lot of resistors, this tool can actually save you a lot of time. How? By making sure that your resistors are bent to exactly the correct length, so that they go through the hole on the first try, without any fuss The tool itself is just a piece of injection-molded plastic, with slots on both sides for different sizes (i.e., power rating), and for different total lead lengths. You hold the resistor in the appropriately sized slot and bend the leads down. Above on the right are two resistors, one bent by hand, and one bent with the tool. The one bent with the tool looks much neater and only takes about half as much time to bend. Mind you we're only talking about a few seconds in either case, but if you're installing a lot of resistors....
	2) Vacuum suction pen placement tool. Little parts can be hard to pick up. That's where this comes in handy! Push the button to expel the air, touch down on a flat surface and release the button to form suction. Works great for just long enough to get your part where it needs to be. Interchangable suction cups allow you to work with different sized parts.
	3) Chip inserter. This tool is designed to insert a DIP chip into a circuit board even though the leads are bent outwards, as they come from the factory. You slide the chip into the end of the tool, put it where it goes, and press the button to push it into the baord. When aligned correctly, they do a good job of putting even pressure across the chip. However, Dan's Data suggests avoiding these-- and truth be told, we don't use them much. However, they are totally cool looking. As we'll see next there are better ways to solve this problem.
	You need a different one for each package style. We have two - they're cheap at our local surplus stores.
	4) IC Lead Straightener Tool. When you get chips, the leads aren't quite parallel, so they don't quite fit in a socket or PCB without some prebending. A quick squeeze of this crimper, and they fit perfectly. By performing the straightening role, it eliminates the primary need for the DIP insertion tool, which is to straighten the leads as they are inserted. Accommodates two different widths of DIP ICs in a variety of lengths.
	5) IC Popper. When you are scavenging parts off of boards, you need a way to get the chips off. Slide the very fine wire ends under surface mount components to lift them off when using hot air to melt the solder.