co TU short Answer


Year 2014

  1. Write the major advantages of floating-point representation.
    Ans: The major advantages of floating-point representation are:
    a. provides a very large range.
    b. supports high performance applications.
    c. better accuracy.

Ans: Floating-point represent have two advantages over integers. First, they can represent values between integers. Second, because of the scaling factor, they can represent a much greater range of values. On the other hand, floating point operations usually are slightly slower than integer operations, and you can lose precision.

  1. What will be the solution of resource conflict pipeline hazards?
    = The solution of resource conflict pipeline hazards is:
    a. use separate memory for data and instruction.

Solution of data dependency conflict

  1. Hardware interlocks
  2. operand Forwarding
  3. Delayed Load

solution of branch conflict
a .pre-fetch Target Instruction

  1. Branch Target Buffer
  2. Loopbuffer
  3. Branch Prediction
  4. Delayed Branch
  1. What is opcode.

=  In computing, an opcode (abbreviated form operation code, also known as instruc-tion machine code, instruction code, instruction syllable, instruction parcel or  opstring)is the portion of a machine language instruction that specifies the operation  to be performed.
Ans : opcode is an instruction that tells processor what to do with the variable or data written beside it.

  1. Why the size of data register is 16bit in Basic computer.
    = Data register is a storage space for units of memory that are used to transfer data for immediate use by the CPU (Central Processing Unit) for data  processing. And the memory address of a basic computer is also 16bit.

Ans:- DR (Data Register16 bits) is used to contain a second operand for dyadic operations such as add, sub, and, or. TR (Temporary Register16 bits) is an extra register for storing data or addresses. INPR and OUTR (Input and Output Registers, 8 bits) are used to communicate with the input and output devices.

  1. Why daisy chaining required?
    = The daisy chaining is required as the chains include connecting to a system on a non-routed network via a gateway system, preserving sessions on the initial computer while working on a second computer, to save bandwidth or improve  connectivity on an unstable network by first connecting to a better connected
    6. Differentiate between strobe and handshaking.
    =  The difference between strobe and handshaking is: strobe uses a single control line      signal to time each transfer whereas handshaking uses two control signals.
    7. Define locality of reference.
    =  The  tendency  of  a  processor  to  access  the  same  set  of  memory   locations      repetitively over a short period of time is known as locality of reference.
  2. What is associative memory?
    = An associative memory can be considered as a memory unit whose stored data can
    be identified for access by the content of the data itself rather than by an address
    or memory location.
    9. Define process.
    =  A process is the instance of a computer program that is being executed by one or
    many threads. It contains the program code and its activity.
    10. Explain loosely coupled multiprocessor.
    =   A loosely coupled multiprocessor system is a type of multiprocessing where the
    individual processors are configured with their own memory and are capable of
    executing user and operating system instructions independent of each other. This
    type of architecture paves the way for parallel processing.


  • Define the term normalization with respect to a floating point number?

Floating point normalization means choosing the exponent to prevent leading zeros in the significant on rounding, making the leading significant digit non-zero allows retention of the maximum number of digits.

  • Write down the symbolic designation of a shift microoperation where the shifting is carried out without loss of information.

The circular shift also known as rotate operation circulates the bits of register without the loss of information
Symbolic designation Description
RR ← cil R Circular shift-left register
RR ← cir R Circular shift-right register

  • How I/O instruction is identified in a basic computer?

Through memory, register and I/O reference.

  • Difference between RISC and CISC
Memory unit is present to implement the instructions There is no memory unit and registers store data
It is microprogramming unit It has a complex design of compiler
Its compiler design is easy Compiler design is complex
Its calculations are slower yet precise Perform mathematical calculations faster
Their decoding is difficult Decoding of its instructions is easier
Instructions are complex so it takes time in execution It is faster as its instructions are simple
External memory mandatory requirement No external memory requirment


  • Write down the uses of sequencer in a microprogrammed control organizations?

To present an address to the control memory so that a microinstruction may be read and executed

  • How is effective address calculate in index registered addressing mode?

 The operand’s offset is sum of the content of a base register BX or BP and an index register SI or DI.
Example: ADD AX, [BX+SI]

  • List solution to control hazards?
  • Resource Conflict Solution
  • Data dependency Solution
  • Handling of branch instruction


  • What is the disadvantage of programmed I/O?

Disadvantage of programmed I/O is that CPU spends most of its time in a tight loop waiting for the device to become ready.

  • Difference between logical and virtual address?

Logical addresses are those seen and used by the assembly programmer, whereas virtual addresses are those directly corresponding to the logic levels of the hardware address bus.

  • Define associative memory?

An associative memory can be considered as a memory unit whose stored data can be identified for access by the content of the data itself rather than by an address or memory location
Computer Organization 2016
Group A

  1. What are two advantages of fixed-point operation over floating-point operation?

Advantages of fixed-point operation over floating-point operation are:
-It can support a much wider range of values.
-It is much faster than floating point operation

  1. If R=11001100, determine the value of R after Logical Shift Right.

Shr 01100110

  1. What is the purpose of control memory?

The purpose of control memory is it sends control signal within the processor to move data from one register to another and activate ALU functions.

  1. What is the importance of subroutine?

Importance of subroutine is:
-It enables to reuse code in the multiple programs
-It reduces the code redundancy

  1. Why control data register is called pipeline register?

Control data register is called pipeline register because it allows the execution of the microoperation specified by the control word simultaneously with the generation of the next microinstruction.

  1. Write the example of instruction format of an accumulator type organization.


  1. For what kind of processing an array processor are used?

Array processor is used to perform the computation on large array of data which improves the performance of computer.

  1. Differentiate between address space and memory space.
Address Space Memory Space
1.It is the set of virtual address used by the programmer. 1.It is the set of address in a main memory


  1. What is the use of polling method?

Polling method is used to check the readiness of the controlling devices connected to the computer often with the low level hardware.

  1. In which case the efficiency of loosely coupled system is greater than tightly coupled system.

The efficiency of loosely coupled system is greater than tightly coupled system because it has individual processor configured with own memory and capable of executing user and operating system instruction independently.
Year 2017

  1. What is the advantage of normalized floating point number?
  • The advantage of normalized floating point number is that it helps to provide more accuracy than corresponding to the de normalized number and hence can be represented in normalized form.
  1. Why control data register in a micro programmed control organization is called pipeline register?
  • Control data register in a micro programmed control organization is called pipeline register because it allows the execution of the micro operation specified by the control word simultaneously with the generation of next microinstruction.
  1. What is the different technique used to achieve parallel processing?
  • The different technique used to achieve parallel processing are:
  1. SIMD(Single Instruction Multiple Data)
  2. MIMD(Multiple Instruction Multiple Data)
  3. Different between address space and memory space?
  • Address spaceis how operating system keeps track of memory given to each program. Memory space is the actual physical memory from the heap. Address space is virtual and also known as virtual memory.
  1. Why interrupt initiated I/Ois better than programmed I/O techniques?
  • Interrupt initiated I/O is better than programmed I/O techniques because is reduced latency. The processor has to temporarily halt its work in programmed I/O, whereas in interruptI/O, the processor continues to perform and only halts when interrupt is received.
  1. Why peripheral are connected with computer through interface?
  • Peripheral are connected with computer through interface because the propose of interface is to provide compatible connection between computer and the port where the peripheral device are connected.
  1. Write a micro instruction format for basic computer?
  • The three fields F1, F2, and F3 specify microoperations for the computer. The micro operations are subdivided into three fields of three bits each. The three bits in each field are encoded to specify seven distinct microoperations. This gives a total of 21 microoperations.
  1. Why hierarchy of memory is maintained?
  • Hierarchy of memory is maintained because whenever we shift from top to bottom inside the memory hierarchy, then the capacity will increase. When we shift from bottom to top inside the memory hierarchy, then the cost for each bit will increase which means an internal Memoryis expensive compared with external memory.
  1. Difference between vector and array processing?
  • An array processingis made up of indexed collections of information called indices whereas Vectors are sometimes referred to as “blocks” of computer data.


  1. Define cache coherence?
  • In computer architecture, cache coherenceis the uniformity of shared resource data that ends up stored in multiple local caches.

Year pratap

  1. Convert (245)10 to 9’s complement.

=   999-245=754
So, the 9’s complement of 245 is 754.

  1. What is register value of A after arithmetic right shift is A=11011101?

=The register value of A after right shift will be A=11101110.

  1. Define interrupt.

=An interrupt is a signal to the processor emitted by hardware or software indicating an event that needs immediate attention. An interrupt alerts the processor to a high priority condition requiring the interruption of the current code the processor in executing.

  1. How the size of program counter in basic computer determined?

= Program Counter holds the address of next instruction to be executed. After instruction is executed, it will incremented by 1 i.e.PC=PC+1 moreover PC will be point to the next instruction.

  1. Define hypercube.

=Hypercube or binary cube multiprocessors structure is a loosly coupled system which is composed of N=2n processors interconnected in an n-dimensional binary cube.

  1. Define strobe.

=In computer or memory technology, a strobe is a signal that is sent that validates data or other signals on adjacent parallel lines.

  1. Define pipeline hazards.

=Pipeline Hazards are situations that prevent the next instruction in the instruction stream from executing during its designated clock cycles. Any condition that causes deviation in the pipeline operation is called hazard.

  1. What is locality of reference ?

=Locality of reference also known as the principle of locality is the tendency of a processor to access the same set of memory locations repetitively over a short period of time.

  1. What is the function of IOP?

=IOP i.e.input-output processor is a processor with direct memory access capability. IOP is similar to a CPU except it is design to handle the details of I/O processing. IOP instructions are specially designed to facilitiate I/O transfer.
So, the function of IOP is to handle the details of I/O processing.

  1. Define critical section.

=Critical section is a code segment that access shared memory and has to be executed as an atomic action.i.e. when processor executing critical section, it holds the shared memory which can not be accessed by any other program(such as semaphore).
2018 Makeup

  1. What is demerit of 1’s complement technique?
  • It is not very simple to understand because it is very much different from the conventional way of representing signed numbers.
  • There are two notations for 0 (0000 and 1111), which is very inconvenient when the computer wants to test for a 0 result.


  1. Write a micro operation for fetch and decode instruction.
  • T0: AR ß PC

T1: IR ßM[AR], PC ß Pc+1
T2: D0,…..,D7ß Decode IR(12-14), ARßIR(0-11), Iß IR(15)

  1. What are advantage of zero address instruction?
  • The advantage of zero-address instruction computers is that they have short programs.


  1. What is limitation of Flynn’s classification?
  • Fails to project the concurrency in pipeline processors as degree of parallelism doesn’t account for concurrency handle by pipelined design.


  1. Differentiate between set associative and direct mapping?
  • Direct mapping:

The CPU address of 15 bits is divided into two fields. The nine least significant bits constitute the index field and the remaining six bits form the tag field.
Set associative mapping:
In this mapping, each word of cache can store two or more words of memory under the same index address. Each data word is stored together with its tag and the number of tag-data items in one word of cache is said to form a set.

  1. Define strobe control method.
  • The Strobe Control method of asynchronous data transfer employs a single control line to time each transfer. This control line is also known as strobe and it may be achieved either by source or destination, depending on which initiate transfer.


  1. Make distinction between loosely coupled and tightly coupled microprocessor system?
  • Tightly coupled:

Tight coupling (or tightly coupled) is a type of coupling that describes a system in which hardware and softwareare not only linked together, but are also dependent upon each other. It is also called heavily coupled.
Loosely coupled:
Loosely coupled system is one in which each of its components has, or makes use of, little or no knowledge of the definitions of other separate components.Subareas include the coupling of classes, interfaces, data, and services.

  1. Difference between memory-reference and register-reference instruction?
  • Memory-reference Instruction:

A memory-reference instruction uses 12 bits to specify the address and one bit to specify the addressing mode.

  • Register-reference Instruction:

A register-reference instruction specifies an operation on or a test of the AC register. 12 bits are used to specify the operation or test to be executed.

  1. How hardware interlock techniques resolve data dependency?
  • An interlock is a circuit that detects instructions whose source operands are destinations of instructions farther up in the pipeline. This approach maintains the program sequence by using hardware to insert the required delays.


  1. Define vector instruction.
  • The operation on multiple data in just one instruction is also called Single Instruction Multiple Data (SIMD) or they are also termed as Vector instructions. The data for vector instruction are stored in vector registers. Each vector register is capable of storing several data elements at a time.

Computer Organization – 2019 Solution

  1. What are the methods of representing negative integers? Give examples.
    The methods of representing negative integers are:
    Signed magnitude
    b. One’s complement
    c. Two’s complement
  2. What is the value of register A after performing arithmetic shift right if A=11101010?
    After performing arithmetic right shift, A= 11110101.
  3. How is handshaking different from strobe?
Handshaking Strobe
1.    It is a communication in which the signal is sent by the sender and received by the receiver.
2.    Bi-directional.
3.    It does not matter about the hold time and transmission time.
1.    It is sent by the signal sender without caring about the signal receiver.
2.    Uni-directional.
3.    The strobe signal checks for the hold time and transmission time.


  1. What is associative memory?
    An associative memory can be considered as a memory unit whose stored data can be identified for access by the content of the data itself rather than by an address or memory location.
  2. Write a microinstruction format of a basic computer.

The microinstruction format of a basic computer is as:

F1(19-17) F2(16-14) F3(13-11) CR(10-9) BR(8-7) AD(6-0)

F1,F2,F3 : Microoperation field, each field 3 bits
CD : Condition for branching 2 bits field
BR : Branch 2-bits field
AD : address 7 bits field

  1. How daisy chaining assigns priority?
    The daisy-chaining method of establishing priority consists of a serial connection of all devices that request an interrupt. The device with the highest priority is placed in the first position, followed by lower-priority devices up to the device with the lowest priority, which is placed last in the chain.
  2. Define locality of reference.
    Locality of reference refers to a phenomenon in which a computer program tends to access the same set of memory locations for a particular time period.
  3. Differentiate between address space and memory space.
Address space Memory space
1.    Address space is virtual and also known as virtual memory.
2.    It is a memory management technique that allows the users to execute programs larger than the actual physical memory.
1.    Memory space is the actual physical memory from the heap.
2.    It refers to the actual RAM of the system attached to the motherboard


  1. Define cache coherence.
    Cache coherence refers to the concept of shared resource data being stored in various local caches uniformly at the same time.
  2. Why is interrupt initiated I/O better than programmed I/O?
    In interrupt initiated I/O the processor does not wait for until the I/O operation is complete. Rather, the processor normally does the other task unlike programmed I/O. As a result, an interrupt I/O module is faster and better than programmed I/O.

Group “A”

  • When is floating point number said to be normalized?
  • A floating point numberis normalized when we force the integer part of its mantissa to be exactly 1 and allow its fraction part to be whatever we like


  • Which arithmetic shift micro operation divide the content of register by 2 after every shifting?
  • Arithmetic right shift divides the content of register by 2 after every shifting.


  • What is disadvantage of strobe control transfer?
  • The disadvantageof the strobe method is that, the source unit initiates the transfer has no way of knowing whether the destination unit has actually received the data item that was places in the bus.


  • What is the limitation of Hardwired control organization?
  • The limitation of Hardwired control organization is it requires change in wiring if the design has to be controlled.


  • Define SIMD computer.
  • SIMD computer is a class of parallel computer with multiple processing elements that perform the same operation on multiple data points simultaneously.


  • Why control memory is considered to be ROM?
  • Control memory is said to be ROM because within it all control information ispermanently stored.


  • List out the techniques of parallel processing.
  • The techniques of parallel processing are:
    • Single Instruction Single Data
    • Single Instruction Multiple Data
    • Multiple Data Single Instruction
    • Multiple Data Multiple Instruction


  • Compare memory mapped I/O and isolated I/O.
  • In mapped I/O memory and I/O both have same address space whereas in isolated I/O both memory and I/O have separate address space.


  • Explain the concept of memory interleaving.
  • Memory interleavingis a technique that CPUs use to increase the memory bandwidth available for an application.


  • Define vector processing.
  • Vector processingis the process of using vectors to store a large number of variables for high-intensity data processing like weather forecasting, human genome mapping