Sample questions for Computer Organization

  1. What is the difference between isolated I/O and Memory –Mapped I/O? What are          

     the advantages of each?

  1. Discuss various modes of transfer? Elaborate the mode which is used in high speed communicating devices.
  2. What is daisy chaining?
  3. UART stands for ___________________________________________.
  4. What is baud rate?
  5. What is handshaking?
  6. What is strobe control?
  7. What is the difference between source initiated and destination initiated data transfer.
  8. Differentiate isolated mapping with memory mapped I/O.
  9. What is cycle stealing?
  10. What is interface unit? What are the reasons for using interface unit.
  11.   Differentiate between RISC and CISC.
  12. Convert the following numerical arithmetic expression into reverse Polish notation and show the stack operations for evaluating the numerical result.

(3+4)[10(2+6)+8]

  1. Explain different addressing modes with the help of a suitable example.
  2. Implement the following arithmetic expression with zero address instruction

X=(A+B)*(C+D)

  1. Discuss various types of CPU organization.
  2. Explain the general register organization with the help of a suitable diagram.
  3. The control memory has 4096 words of 24 bits each.

a)      How many bits are there in the control address register?

b)      How many bits are there in each of the four inputs shown going into the multiplexers?

c)      .gifWhat are the number of inputs in each multiplexer and how many multiplexers are needed?

 

Fig.1

 

 

 

  1. What is the difference between hardwired control and micro programmed control   

      associated with a control?

  1. The system shown in fig.1 uses a control memory of 1024 words of 32 bits each. The microinstruction has three fields. The micro operation filed has 16 bits.

a)      how many bits are there in the branch address field and the select field?

b)      If there are 16 status bits in the system, how many bits  of the branch logic are used to select a status bit?

c)      How many bits are left to select an input for the multiplexes?

21. What is a control memory? Discuss the microinstruction code format of the        control memory. In how many parts it is divided? Also discuss how many bits are           allocated to each field.

22. What is the difference between the microprocessor and the micro program?

Is it possible to design a micro-processor without a microprogramming? Are all micro programmed computers also microprocessor? 

     23. What is the difference between the microprocessor and the micro program?

            Is it possible to design a micro-processor without a microprogramming? Are all 

            micro programmed computers also microprocessor? 

     24. List the micro-operations executed for the following instructions

(a)    ADD (b) BUN (c) BSA (d) ISZ (e) AND

     25. Explain direct ad indirect addressing modes.

     26. Draw and explain the common bus system for a basic computer. How does a bus           concept help in the design of a computer?

  1. Discuss the working of a micro program sequencer.

 

  1. (a) Discuss the micro programmed control organization.

      (b) Discuss the working of the micro program sequencer.

29. Explain the following cache mapping techniques with example.

(i)                  Fully associative

(ii)                Direct

            (iii)      Set associative

30. What is hit and miss ratio?

31. What is associative memory? Explain the working in detail.

32. What is virtual memory? Explain the working in detail.

33. Explain the working of memory management hardware.

34. What is the role of Key register in associative memory? Explain with the help of a    

      suitable example.

35. Why memory hierarchy concept is used?

36. What is principle of locality? Why it is useful?

37. Explain Booth’s Algorithm for Multiplication.

38. What is interrupt cycle? Explain.

39. Explain with the help of diagram the working of a arithmetic and logic control 

      unit.

40. Show the block diagram of the hardware that implement s the following register

      transfer statement.

                                       yT2: R2←R1, R1←R2

 

41. Represent the following conditional control statement by two register transfer 

     statements with control functions.

If(P=1)then(R1←R2 ) else if (Q=1) then(R1←R3)

42. A digital computer has a common bus system for 16 registers of 32 bits each. The 

      bus is constructed with multiplexers.

(a)    How many selection inputs are there in each multiplexer?

(b)   What size of multiplexers is needed?

(c)    How many multiplexers are there in the bus?

43. Draw bus system for 4 registers using multiplexers.

44. Draw bus system for 4 registers using decoder and tri-state buffers.

45. List the registers used in the basic computer along with the length and function.

46. Explain with suitable diagram the hardwired implementation of control unit.

47. A computer uses a memory unit with 256K words of 32 bits each. A binary 

      instruction code is stored in one word of memory. The instruction has four parts: 

      an indirect bit, an operation code, a register code to specify one of 64 registers,

      and an address part.

(a)     How many bits are there in the operation code, the register code part, and 

       the  address part?

(b)   Draw the instruction word format and indicate the number of bits in each part.

(c)    How many bits are there in the data and address inputs of the memory?

 

    48. What are the two instructions needed in the basic computer in order to set the E 

           flip-flop to 1?

    49. Explain why each of the following micro operations cannot be executed during a 

          single clock pulse. Specify a sequence of micro operations that will perform the 

          operation.

(a)    IR←M[PC]

(b)   AC← AC+TR

(c)    DR←DR+AC (AC does not change)

 

50.    Explain micro programmed control unit with the help of a block diagram.

51.     A two-way associative cache memory use blocks of four words. The cache can accommodate a total of 2048 words from main memory. The main memory size is 128K X 32

a)      formulate all pertinent information required to construct the cache memory.

b)      What is the size of the cache memory?

52.    An address space is specified by 24 bits and the corresponding memory space by 16 bits.

a)      how many words are there in the address space?

b)      How many words are there in the memory space?

c)      If a page consists of 2K words, how many pages and blocks are there in the system?

53.    What is Logical address?

54.    Explain with the help of the suitable diagram how logical addressed is mapped into physical diagram.

55.    Why Memory Management Hardware is required?

56.    Write a short note s random access memory and read only memory.

57.    Write a short note paging.

58.    Explain serial data transfer. Why is it slower than parallel data transfer?

59.    What is a I/O  processor?

60.    Dirrerentiate between synchronous I/O and Asynchronous I/O devices. Give an example.

61.    Why are the read and write control lines in a DMA controller should be bidirectional? Under what condition and for what purpose are they used as inputs and as outputs?

62.    What is the basic advantage of using interrupt initiated data transfer over transfer under program control without an interrupt?

63.    How are negative numbers represented in computers? Explain with examples.

64.    How are floating point numbers represented internally in a computer? Can it handle zero?

 

 

 

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