Technical Questions

Q:

What are set up time & hold time constraints? What do they signify? Which one is critical for estimating maximum clock frequency of a circuit?

Answer

Suppose your flip-flop is positive edgetriggered. time for which data should be stable prior to positive edge clock is called setup is called setup time constraint.


Time for which data should be stable after the positive edge of clock is called as hold time constraint.


If any of these constraints are violate d then flip-flop will enter in meta stable state, in which we cannot determine the output of flip-flop.


there are two equation:


1. Tcq + Tcomb > Tskew + Thold


2. Tcq + Tcomb > Tskew + T - Tsetup


Tcq is time delay when data enters the flip flop and data comes at output of flip flop.


Tcomb is the logic delay between two flip flop.


Tskew is the delay of clock to flip flop: suppose there are two flip flop, if clock reaches first to source flip flop and then after some delay to destination flip flop, it is positive skew and if vice versa then negative  skew. 


so if you take 2 eq you will see that setup time is the determining factor of clock's time period.

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Subject: Hardware

1 5800
Q:

Two main measures for the efficiency of an algorithm are

A) Time and Space B) Complexity and Memory
C) Data and Space D) Memory and Processor
 
Answer & Explanation Answer: A) Time and Space

Explanation:

Two main measures for the efficiency of an algorithm are Time and Space.

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26 5741
Q:

Default read write and execute permissions given to a file for owner, group and others are

A) 6-4-4 B) 6-4-2
C) 6-4-6 D) 6-6-6
 
Answer & Explanation Answer: A) 6-4-4

Explanation:

Default permissions given to a file are:

Owner - read write and execute - 6

group - write - 4

others - write - 4

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6 5718
Q:

A shared database should:

A) be accurate and available. B) provide for backup and recovery.
C) be secure. D) All of the above.
 
Answer & Explanation Answer: D) All of the above.

Explanation:
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Filed Under: Database

3 5653
Q:

A ternary relationship involves how many entities?

A) 3 or less B) 3
C) More than 3 D) 3 or more
 
Answer & Explanation Answer: B) 3

Explanation:
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Filed Under: Database

0 5643
Q:

Which of the following indicates the maximum number of entities that can be involved in a relationship?

A) Minimum cardinality B) Maximum cardinality
C) ERD D) Greater Entity Count (GEC)
 
Answer & Explanation Answer: B) Maximum cardinality

Explanation:
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Filed Under: Database

1 5546
Q:

SNOBOL is mainly used for

A) Text Operation B) String operations
C) List operations D) Numerical operations
 
Answer & Explanation Answer: B) String operations

Explanation:

SNOBOL is a high-level computer programming language used especially in manipulating textual data. It is mainly used for string operations and was developed between 1962 and 1967.

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52 5525
Q:

Point out the error, if any, in the following program.

#include "stdarg.h"

main()

{

     display ( 4, 12.5, 13.5, 14.5, 44.3);

}

display(int num, ...)

{

       float c; int j;

        va_list ptr;

        va_start (ptr, num);

        for ( j = 1; j <= num; j++)

        {

            c = va_arg ( ptr, float );

            printf ("\n%f", c);

         }

}

Answer

While extracting a float argument using va_arg we should have useed 


c = va_arg (ptr, double)

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Subject: Programming

1 5482