Provided by www.YuvaJobs.com - 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
 c. thread id
 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