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STMicroelectronics Placement Paper : Aptitude - General

ST MICROELECTRONICS PAPER ON 15TH NOVEMBER 2007

PART- A
a.9*1 Apti Questions
b.Virtual memory is greater than physical memory
c.Cycle stealing is related to DMA?
d.Conditional operation are stored in flag seg?
e.Some question on stack of heap
f.Charging of MOS transistor
g.Question on current change in mor due to change in Vge.
h.Time constant of RL network
i.One more question on RL network
j.Solve the K-Map
k.Resistance of MOS transistor when the W/L relation is given
l.Which of then is memory related op, Buddying, monitor.
PART - B
1.Question on counter (divide by 4, 50% DC)
2.4,s Complement of a no.
3.Max operating frequency of a sequential network (166.66 MHz)
4.Some que on microprocessor. Block diagram was given
5.Sampling is done at 210 Hz of a signal containing 50., 100 & 150 Hz signal. Then the signal is passed there a LPF of 10.5 Mz cut off freq. What is the freq. component of the output
6.There are poles of OP at 10 KHz Find the value of R1 & R2.
7.Some question on current consolidated current source
8.A signal contain band limited signal B0, 2B0, 3B0.......... NB0. Each of them is sampled at nygyist rate and quatind to 8 bit. Now what is bit rate?
9.Find out noise margins of digital circuit V0,V10, V12, V02, I0n, I......... were given
10.PCM. The no. of bits is microased from 6 to 8. What is the ratio of SNR and bandwidth
11.V0/V1= jwt+ 104*2 / jw+ 104 w= 104

V1 = Cor (wt) Now determine V0.

Ans were in the form of Cos (wt + something)
Sin (wt + something)
ley (wt + something)

12. Multivibration using 555
13. Some question on transmission line.
All the 3 sections was compulsary and u,ve to give a preference among the section 2 & sec 3 so that the weightage for the second one will get doubled. Negative marking was there.

here are some of the ques which i remember

1. which conversion is not possible
a. float to int
b. int to float
c. char to float
d. all are possible
Ans: d

2. threads have which thing in common
a. register set
b. data section
d. ...
Ans : b

3. one que like
main()
{
int x=5, y;
y= x*x++ * ++x ;

// print x and y
}

4. A CPU has four group of instruction set A, B, C, D
CPI of A = 1
CPI of B=3
Cpi of c =2
cpi of d= 4
the cpu access 20% of A, 30% of b, 30% of C and 20 % of D
what will be the average CPI.

Ans: 1*20/100 + 3* 30/100 + 2* 30/100 + 4* 20/100
( this que was repeated in section 2 & 3)

5 . a question on hit ratio n effective memory access time.

6. main()
{
int a=10,b=5
while ( --b>=0 && ++a)
{
--b;
++a;
}
print (a);
print (b);
}
ans: a=16, b=-2

7. main()
{
char i;

for (i=0; i<=255; i++)
{
printf("%c", i);
}
}
Ans: never ending loop

8. One question on controls systems
to find the transfer functn
poles n zeroes were given in a graph
ans: s(s-2)/(s-3)(s-4)

9. one question on sampling theorem, if sampling frequency is fs then the signal having same characteistics will be of frequency....(in terns of fs)

10. one on the signal to noise ratio
- if the amplitude of the signal is reduced to half & N bits samples r used with M quantiztn level, then the SNR will be reduced by a factor of
Ans: 6 db

11. questn on calculating the bit rate to be transmitted across the given capacity channel

12. calculating the checksum for the bits to be transmitted given the frame- 11000101 and generator is1100.

13. calculating the no of bits required for the error detection & the error correction for the given codeword set.
codeword a:
0000
0001
0011
1111
codeword b:
101111
.
.
.
.
110101

14. options were given to choose as which was an example of multitasking.
a:multiple remote users accessing a server
c:multiple programs resident in memory

15. CA in CSMA/ CA stands for
a. collision approval
b. collision avoidance
c. critical access

16. in a triangle, without changing the angle, if we double the sides,then new area will be
asn. four times

17. there is a pipe having dia 6mm, then how many pipes having 1mm dia wiill be needed to provide same amount of water.
ans . 36

18. in which of the folwng schemes after page replacement the entered page will enter in the same memory location as of the replaced one
a. direct mapping ( Ans)
b. n-set associative
c. associative
d. none of them

19. belady anamoly is related to.
ans. page replacement algos

20.which one uses cache mechanism
ans TLB

21.what will happen in following code..
signal(mutex)
critical section
wait(mutex)

ans. violation of mutual exclusion

22.an RLC ckt was given, fuctioning of ckt to be determined.
a: will act like FM
b: PM
c:AM
d: none of the above

23.
int i=0;
switch(i)
{
case 1: printf("hi");
case 0: printf("zero");
case 2: printf("world");
}

ans: zeroworld

24.which one is the declaration of static string
a: static string
b: ,static string,
c: "static string"
d:char sting[30]

25.a que on file handling in c
a: file cant be opened
b:msg.txt is copied to msg
c:only first string be copied
d:

26. which of the fuction will store a 100 char string in X
c.gets(x)

STMicroelectronics Placement Paper : 15 November 2007

ST MICROELECTRONICS PAPER ON 15TH NOVEMBER 2007

PART- A
a.9*1 Apti Questions
b.Virtual memory is greater than physical memory
c.Cycle stealing is related to DMA?
d.Conditional operation are stored in flag seg?
e.Some question on stack of heap
f.Charging of MOS transistor
g.Question on current change in mor due to change in Vge.
h.Time constant of RL network
i.One more question on RL network
j.Solve the K-Map
k.Resistance of MOS transistor when the W/L relation is given
l.Which of then is memory related op, Buddying, monitor.
PART - B
1.Question on counter (divide by 4, 50% DC)
2.4,s Complement of a no.
3.Max operating frequency of a sequential network (166.66 MHz)
4.Some que on microprocessor. Block diagram was given
5.Sampling is done at 210 Hz of a signal containing 50., 100 & 150 Hz signal. Then the signal is passed there a LPF of 10.5 Mz cut off freq. What is the freq. component of the output
6.There are poles of OP at 10 KHz Find the value of R1 & R2.
7.Some question on current consolidated current source
8.A signal contain band limited signal B0, 2B0, 3B0.......... NB0. Each of them is sampled at nygyist rate and quatind to 8 bit. Now what is bit rate?
9.Find out noise margins of digital circuit V0,V10, V12, V02, I0n, I......... were given
10.PCM. The no. of bits is microased from 6 to 8. What is the ratio of SNR and bandwidth
11.V0/V1= jwt+ 104*2 / jw+ 104 w= 104

V1 = Cor (wt) Now determine V0.

Ans were in the form of Cos (wt + something)
Sin (wt + something)
ley (wt + something)

12. Multivibration using 555
13. Some question on transmission line.

STMicroelectronics Placement Paper : Thapar University, Patiala ,29 August 2007

All of this paper had different no of questions...

I had given paper of embedded software so I am giving its details .Paper had two part:

1. 1 marks questions (10 questions of aptitude and 10 questions on OS, Microprocessor and DS)

2.2 marks questions on C(15 questions)

Part 1: 1 marks questions were like...(Aptitude was quite easy)

There is pipe with given radius, a small pipe of given radius. How many pipes of smaller radius will contain the same quantity of liquid kept by larger radius tube?

A ladder is standing against a wall of 25m height at a distance of 7 km from wall. Suddenly Ladder slips 4m down from top. How much will it move from the earlier 7m distance from the wall?
A person likes 225 not 224, like 900 not 800, from given vat will he like…1600,1500.. (Answer is simply ny given square term(1600)..c paettern of his liking
Three co-ordinates of triangle was given.. we had too find type of triangle it is..
A square is cut from a circle and a circle is cut from that square..how much area is remaining ….
In equilateral triangle a circle is drawn. In that circle one square is drawn. Find the ratio of area of equilateral triangle to square?
Question on simple average speed..
Question on angle between hands of a clock…

Next 10 questions were technical

1. Int *p;

P=(int *p)malloc(100);

Wat is sizeof(p),sizeof(*p)

2. A question on find the worst case complexity of Quick Sort( ans :O(n2) )

3. Piggy Backing is For ?(Acknowledgement)

4. In POP operation of Microprocessor how it process the instruction

Ans: it pops the instruction and decrements the stack pointer

Where does Global,Local and static variables of a program lie?
3 questions on H/w ..that I could not solve….
1 question on Boolean expression(a simple one)

2 marks questions…

1 #define xyz abc*cd

#define abc 10

#define cd 10

Main()

{

Int k;

K=20-xyz;

K==?

}

Ans: -80

2. Static variables don’t change their value as they are stored in

a) stack b) data segment c) heap d) none

3. #pragma pack(1)

Struct a

{

Int a:4;

Int b:45;

Char c;

}

What is the size of struct if int is of four bytes .

Ans is 5

4. a question on bitwise operator

5.int i=90;

Char *p;

P=(char *)&i ;

P++;

Pointer is I ncremented by 2,1,4 or none of these

6.#define scanf “%s is string”

Main()

{

Printf(scanf,scanf);

Ans; %s is string is string

7 char str={“neha”);

printf(“hello \n” %s” \n”,str);

output : ?

8 One question on page table. we had to find page size

9 . One question on memory acces time of a program with given hit ratio and given cache access time..( revise the formula from OS)

10. Find the number of 1’s in the following expression

(3*4096 + 16*1024+ 3)

11. 1 question on recursion

int i=89;

Int *p;

Char *t;

P=&I;

T=(char *)&I;

If( *p==*t)

Printf(“yes”);

Else

Printf(“no”);

Tell the o/p.

12. Again 2 question to find output of a c program

STMicroelectronics Placement Paper : Whole Testpaper Thapar University, Patiala - 29 August 2007

Hello Friends, Neha Here

This was the paper of ST microelectronics held at Thapar University on 29 august, 2007

There were 3 types of paper..

IT( For MCA students)
Embedded Software( For BE(CS) and ME/Mtech(CS))
Hardware( For BE(ECE branches) and ME/MTech(ECE))

All of this paper had different no of questions...

I had given paper of embedded software so I am giving its details .Paper had two part:

1. 1 marks questions (10 questions of aptitude and 10 questions on OS, Microprocessor and DS)

2.2 marks questions on C(15 questions)

Part 1: 1 marks questions were like...(Aptitude was quite easy)

There is pipe with given radius, a small pipe of given radius. How many pipes of smaller radius will contain the same quantity of liquid kept by larger radius tube?

A ladder is standing against a wall of 25m height at a distance of 7 km from wall. Suddenly Ladder slips 4m down from top. How much will it move from the earlier 7m distance from the wall?
A person likes 225 not 224, like 900 not 800, from given vat will he like…1600,1500.. (Answer is simply ny given square term(1600)..c paettern of his liking
Three co-ordinates of triangle was given.. we had too find type of triangle it is..
A square is cut from a circle and a circle is cut from that square..how much area is remaining ….
In equilateral triangle a circle is drawn. In that circle one square is drawn. Find the ratio of area of equilateral triangle to square?
Question on simple average speed..
Question on angle between hands of a clock…

Next 10 questions were technical

1. Int *p;

P=(int *p)malloc(100);

Wat is sizeof(p),sizeof(*p)

2. A question on find the worst case complexity of Quick Sort( ans :O(n2) )

3. Piggy Backing is For ?(Acknowledgement)

4. In POP operation of Microprocessor how it process the instruction

Ans: it pops the instruction and decrements the stack pointer

Where does Global,Local and static variables of a program lie?
3 questions on H/w ..that I could not solve….
1 question on Boolean expression(a simple one)

2 marks questions…

1 #define xyz abc*cd

#define abc 10

#define cd 10

Main()

{

Int k;

K=20-xyz;

K==?

}

Ans: -80

2. Static variables don’t change their value as they are stored in

a) stack b) data segment c) heap d) none

3. #pragma pack(1)

Struct a

{

Int a:4;

Int b:45;

Char c;

}

What is the size of struct if int is of four bytes .

Ans is 5

4. a question on bitwise operator

5.int i=90;

Char *p;

P=(char *)&i ;

P++;

Pointer is I ncremented by 2,1,4 or none of these

6.#define scanf “%s is string”

Main()

{

Printf(scanf,scanf);

Ans; %s is string is string

7 char str={“neha”);

printf(“hello \n” %s” \n”,str);

output : ?

8 One question on page table. we had to find page size

9 . One question on memory acces time of a program with given hit ratio and given cache access time..( revise the formula from OS)

10. Find the number of 1’s in the following expression

(3*4096 + 16*1024+ 3)

11. 1 question on recursion

int i=89;

Int *p;

Char *t;

P=&I;

T=(char *)&I;

If( *p==*t)

Printf(“yes”);

Else

Printf(“no”);

Tell the o/p.

12. Again 2 question to find output of a c program

STMicroelectronics Placement Paper : Aptitude - General

ST Microelectronics

there were two papers
1. separate for the hardware (electonics people)
2. and other for the software (comp).

Software paper

There were 3 sections the questions in these sections were mixed with 2-3 aptitude question, questions on comp n/w & OS were 7-8, 1-2 on CSO, 1 que on controls, 1 on sampling theorem some on Comp Arch. & digital logic & 7-8 on C.

section 1 contains 11 questions
section 2 contains 13 que
section 3 contains 13 que ( total = 37 que , marks= 50)

All the 3 sections was compulsary and u,ve to give a preference among the section 2 & sec 3 so that the weightage for the second one will get doubled. Negative marking was there.

here are some of the ques which i remember

1. which conversion is not possible
a. float to int
b. int to float
c. char to float
d. all are possible
Ans: d

2. threads have which thing in common
a. register set
b. data section
d. ...
Ans : b

3. one que like
main()
{
int x=5, y;
y= x*x++ * ++x ;

// print x and y
}

4. A CPU has four group of instruction set A, B, C, D
CPI of A = 1
CPI of B=3
Cpi of c =2
cpi of d= 4
the cpu access 20% of A, 30% of b, 30% of C and 20 % of D
what will be the average CPI.

Ans: 1*20/100 + 3* 30/100 + 2* 30/100 + 4* 20/100
( this que was repeated in section 2 & 3)

5 . a question on hit ratio n effective memory access time.

6. main()
{
int a=10,b=5
while ( --b>=0 && ++a)
{
--b;
++a;
}
print (a);
print (b);
}
ans: a=16, b=-2

7. main()
{
char i;

for (i=0; i<=255; i++)
{
printf("%c", i);
}
}
Ans: never ending loop

8. One question on controls systems
to find the transfer functn
poles n zeroes were given in a graph
ans: s(s-2)/(s-3)(s-4)

9. one question on sampling theorem, if sampling frequency is fs then the signal having same characteistics will be of frequency....(in terns of fs)

10. one on the signal to noise ratio
- if the amplitude of the signal is reduced to half & N bits samples r used with M quantiztn level, then the SNR will be reduced by a factor of
Ans: 6 db

11. questn on calculating the bit rate to be transmitted across the given capacity channel

12. calculating the checksum for the bits to be transmitted given the frame- 11000101 and generator is1100.

13. calculating the no of bits required for the error detection & the error correction for the given codeword set.
codeword a:
0000
0001
0011
1111
codeword b:
101111
.
.
.
.
110101

14. options were given to choose as which was an example of multitasking.
a:multiple remote users accessing a server
c:multiple programs resident in memory

15. CA in CSMA/ CA stands for
a. collision approval
b. collision avoidance
c. critical access

16. in a triangle, without changing the angle, if we double the sides,then new area will be
asn. four times

17. there is a pipe having dia 6mm, then how many pipes having 1mm dia wiill be needed to provide same amount of water.
ans . 36

18. in which of the folwng schemes after page replacement the entered page will enter in the same memory location as of the replaced one
a. direct mapping ( Ans)
b. n-set associative
c. associative
d. none of them

19. belady anamoly is related to.
ans. page replacement algos

20.which one uses cache mechanism
ans TLB

21.what will happen in following code..
signal(mutex)
critical section
wait(mutex)

ans. violation of mutual exclusion

22.an RLC ckt was given, fuctioning of ckt to be determined.
a: will act like FM
b: PM
c:AM
d: none of the above

23.
int i=0;
switch(i)
{
case 1: printf("hi");
case 0: printf("zero");
case 2: printf("world");
}

ans: zeroworld

24.which one is the declaration of static string
a: static string
b: ,static string,
c: "static string"
d:char sting[30]

25.a que on file handling in c
a: file cant be opened
b:msg.txt is copied to msg
c:only first string be copied
d:

26. which of the fuction will store a 100 char string in X
c.gets(x)

STMicroelectronics Placement Paper : STMicroelectronics Paper Aptitude - General

ST Microelectronics

there were two papers
1. separate for the hardware (electonics people)
2. and other for the software (comp).

Software paper

There were 3 sections the questions in these sections were mixed with 2-3 aptitude question, questions on comp n/w & OS were 7-8, 1-2 on CSO, 1 que on controls, 1 on sampling theorem some on Comp Arch. & digital logic & 7-8 on C.

section 1 contains 11 questions
section 2 contains 13 que
section 3 contains 13 que ( total = 37 que , marks= 50)

All the 3 sections was compulsary and u,ve to give a preference among the section 2 & sec 3 so that the weightage for the second one will get doubled. Negative marking was there.

here are some of the ques which i remember

1. which conversion is not possible
a. float to int
b. int to float
c. char to float
d. all are possible
Ans: d

2. threads have which thing in common
a. register set
b. data section
d. ...
Ans : b

3. one que like
main()
{
int x=5, y;
y= x*x++ * ++x ;

// print x and y
}

4. A CPU has four group of instruction set A, B, C, D
CPI of A = 1
CPI of B=3
Cpi of c =2
cpi of d= 4
the cpu access 20% of A, 30% of b, 30% of C and 20 % of D
what will be the average CPI.

Ans: 1*20/100 + 3* 30/100 + 2* 30/100 + 4* 20/100
( this que was repeated in section 2 & 3)

5 . a question on hit ratio n effective memory access time.

6.  main()
{
int a=10,b=5
while ( --b>=0 && ++a)
{
--b;
++a;
}
print (a);
print (b);
}
ans: a=16, b=-2

7. main()
{
char i;

for (i=0; i<=255; i++)
{
printf("%c", i);
}
}
Ans: never ending loop

8. One question on controls systems
to find the transfer functn
poles n zeroes were given in a graph
ans: s(s-2)/(s-3)(s-4)

9. one question on sampling theorem, if sampling frequency is fs then the signal having same characteistics will be of frequency....(in terns of fs)

10. one on the signal to noise ratio
- if the amplitude of the signal is reduced to half & N bits samples r used with M quantiztn level, then the SNR will be reduced by a factor of
Ans: 6 db

11. questn on calculating the bit rate to be transmitted across the given capacity channel

12. calculating the checksum for the bits to be transmitted given the frame- 11000101 and generator is1100.

13. calculating the no of bits required for the error detection & the error correction for the given codeword set.
codeword a:
0000
0001
0011
1111
codeword b:
101111
.
.
.
.
110101

14. options were given to choose as which was an example of multitasking.
a:multiple remote users accessing a server
c:multiple programs resident in memory

15. CA in CSMA/ CA stands for
a. collision approval
b. collision avoidance
c. critical access

16. in a triangle, without changing the angle, if we double the sides,then new area will be
asn. four times

17. there is a pipe having dia 6mm, then how many pipes having 1mm dia wiill be needed to provide same amount of water.
ans . 36

18. in which of the folwng schemes after page replacement the entered page will enter in the same memory location as of the replaced one
a. direct mapping ( Ans)
b. n-set associative
c. associative
d. none of them

19. belady anamoly is related to.
ans. page replacement algos

20.which one uses cache mechanism
ans TLB

21.what will happen in following code..
signal(mutex)
critical section
wait(mutex)

ans. violation of mutual exclusion

22.an RLC ckt was given, fuctioning of ckt to be determined.
a: will act like FM
b: PM
c:AM
d: none of the above

23.
int i=0;
switch(i)
{
case 1: printf("hi");
case 0: printf("zero");
case 2: printf("world");
}

ans: zeroworld

24.which one is the declaration of static string
a: static string
b: ,static string,
c: "static string"
d:char sting[30]

25.a que on file handling in c
a: file cant be opened
b:msg.txt is copied to msg
c:only first string be copied
d:

26. which of the fuction will store a 100 char string in X