Fundamentals of Computer Organisation and Architecture

• What is the role of the processor?

  To execute program instructions in order to run applications
• Name two types of main memory

  1. Random Access Memory (RAM)
  2. Read Only Memory (ROM)
• Which is usually faster: main memory or secondary storage?

  Main memory
• Name two types of information that may be held in main memory

  1. Program instructions
  2. Frequently used data
• What is meant by a bus?

  A series of parallel wires that connects internal components of a computer
• Which bus is used to transport memory addresses?

  Address bus
• Which bus is used to send information to and from different components?

  Data bus
• An address bus is formed from 8 parallel wires. How many addressable memory locations does the address bus allow?

  256 (2^8)
• What effect does increasing the width of the data bus have?

  Increases the volume of data that can be transferred at any one time.
• What is the role of the control bus?

  Carries control signals, including the system clock, that regulates the operation of the computer system
• What name is given to hardware that controls the communication of data between the processor and external hardware devices?

  Input/Output Controller
• Which type of architecture has one set of main memory for instructions and another for data: Harvard or von Neumann?

  Harvard architecture
• Which type of architecture is extensively used in embedded systems: Harvard or von Neumann?

  Harvard
• In which type of architecture are instructions and data stored in the same memory: Harvard or von Neumann?

  von Neumann
• Which type of architecture is used in general-purpose computer systems: Harvard or von Neumann?

  von Neumann
• What is meant by the stored program concept?

  Machine code instructions stored in main memory are fetched and executed serially by a processor that performs arithmetic and logical operations.
• What is the advantage of using the stored program concept?

  Allows one computer to run several different programs
• When using the stored program concept, what two things could the contents of a memory location be interpreted as?

  1. Instructions
  2. Data
• Name the two architectures on which stored program computers can be based

  1. Harvard architecture
  2. von Neumann architecture
• Which type of register is the status register: general purpose or special purpose?

  Special purpose
• Which of the following is not found within a processor?

  A: Control Unit

  B: Main memory

  C: Buses

  B: Main memory
• For what do the letters ALU stand?

  Arithmetic Logic Unit
• What effect does increasing the width of the address bus have?

  Increases the computer’s amount of addressable memory
• Which register holds the instruction that is currently being executed by the processor?

  Current Instruction Register
• What is cache?


  A small portion of fast memory used to store frequently used information in the processor
• What name is given to small storage locations used to hold data temporarily in the processor?

  Registers
• What is meant by this assembly language instructions?

  STR R3, 38


  Store the value that is in register 3 into memory location 38.
• Which register holds the contents of a memory location that has been read from or data that is to be stored?

  Memory Buffer Register
• Which part of a computer’s processor generates signals at a regular frequency?

  Clock
• Which special purpose register is abbreviated as MAR?

  Memory Address Register
• Name the three stages of the fetch-execute cycle


  Fetch, decode, execute
• What name is given to the data to be used in an instruction: opcode or operand?

  Operand
• Form an assembly language instruction that would mean: “Add the value in register 4 to the value in register 5 and store the result in register 3”

  ADD R3, R4, R5
• In which stage of the fetch-execute cycle is the program counter incremented?

  Fetch
• Between which two stages of the fetch-execute cycle is the status register checked?

  Execute and Fetch
• What name is given to the group of instructions that a processor can carry out?

  Instruction set
• In which addressing mode does the value specified by an operand signify a memory address?

  Direct addressing
• In which stage of the fetch-execute cycle is an instruction broken into opcode and operands?

  Decode
• What name is given to a signal sent to the processor by another part of the computer requesting the attention of the processor?

  Interrupt
• Name two parts of a barcode reader

  Laser, lens, photodiodes, mirror