Code: DC-04                                                                Subject: COMPUTER ORGANISATION

Time: 3 Hours                                             June 2006                                                         Max. Marks: 100

 

NOTE: There are 9 Questions in all.

·      Question 1 is compulsory and carries 20 marks. Answer to Q. 1. must be written in the space provided for it in the answer book supplied and nowhere else.

·      Out of the remaining EIGHT Questions answer any FIVE Questions. Each question carries 16 marks.

·      Any required data not explicitly given, may be suitably assumed and stated.

 

 

Q.1       Choose the correct or best alternative in the following:                                         (2x10)

       

a.       Logic gates with a set of input and outputs is arrangement of

 

                   (A)  combinational circuit                     (B)  logic circuit

(C)    design circuits                              (D)  register

       

b.      MIMD stands for

 

(A)    Multiple instruction  multiple data

(B)    Multiple instruction memory data

(C)    Memory instruction multiple data

(D)    Multiple information memory data

            

             c.   A k-bit field can specify any one of

                  

(A)     3k registers                                  (B)  2k registers

(C)   K2 registers                                 (D)  K3 registers

 

             d.   The time interval between adjacent bits is called the

 

(A)    word-time                                   (B)  bit-time

(C)  turn around time                           (D)  slice time        

 

             e.   A group of bits that tell the computer to perform a specific operation is known as

                  

(A)     instruction code                            (B)  micro-operation

(C)  accumulator                                  (D)  register

 

             f.    The load instruction is mostly used to designate a transfer from memory to a processor register known as

 

(A)     Accumulator.                               (B)  Instruction Register.

(C)  Program Counter.                         (D)  Memory address Register.

 

 

 

 

 

             g.   The communication between the components in a microcomputer takes place via the address and

 

(A)     I/O bus                                        (B)  data bus

(C)  address bus                                  (D)  control lines

 

             h.   An instruction pipeline can be implemented by means of

                  

(A)    LIFO buffer                                 (B) FIFO buffer

(C)  Stack                                           (D) None of the above

 

             i.    Data input command is just the opposite of a

                  

(A)   test command                               (B) control command

(C) data output                                    (D) data channel

 

             j.    The average time required to reach a storage location in memory and obtain its contents is called the

 

(A)  seek time                                      (B)  turnaround time

(C)  access time                                   (D)  transfer time

 

 

Answer any FIVE Questions out of EIGHT Questions.

Each question carries 16 marks.

 

  Q.2     a.   Draw the block diagram of four-bit register with parallel load.                             (8)

       

             b.   Define the following:

(i)                  Decoder

(ii)                Multiplexers

(iii)               Demultiplexers                                                                               

            

                   Draw the block diagrams also.                                                                           (8)

 

  Q.3     a.   What is the sequence of external operations needed to store a word into memory?              (4)       

 

             b.   Briefly explain fixed-point representation of numbers.  What is the signed magnitude, 1’s complement and 2’s complement of –9?                              (8)

            

             c.   Give difference between static and dynamic RAM.                                             (4)

 

  Q.4     a.   Draw a diagram of bus system for four registers of 4-bits each. The bus is to be constructed with multiplexers.                                                                                                       (8)

 

             b.   Explain the following:                          

 

                   (i)   Memory-reference instruction.       (ii)  Register-reference instruction.

                   (iii) Input-output instruction.                                                                               (8)

 

  Q.5     a.   Write the instructions for multiplying two unsigned numbers in assembly language.               (8)

       

             b.   Give stack operations to evaluate 3*4+5*6.                                                       (4)

 

             c.   What is the main difference between implied and immediate modes of addressing.               (4)

 

  Q.6     a.   Discuss the Base Register Addressing Mode in detail.                                         (4)

 

             b.   List in detail typical program control instructions of basic computer.                     (6)

 

             c.   What is a cache memory? How is the performance of cache memory measured?                (6)

 

  Q.7     a.   Describe in words and by means of a block diagram how matched word can be read out from an associative memory.                                              (8)   

 

             b.   What is the difference between virtual and physical addresses? How is a virtual address mapped to a physical address ?                                (8)

            

  Q.8     a.   Design an array multiplier that multiplies two 2-bit numbers. Use AND gates and half adders.                                                                     (8)

 

             b.   Derive an algorithm in flowchart form to, multiply two binary numbers in signed-2’s complement representation.                                     (8)

       

  Q.9     a.   What is strobe control?  Draw a block diagram for source-initiated strobe for data transfer.                                                                       (8)                                                             

 

             b.   Write short notes on

(i)                  UART

(ii)                DMA                                                                                                    (8)