computer science as

• What is the function of the Arithmetic and Logic Unit?

  The ALU completes all of the arithmetical and logical operations
• What is the function of the CU?

  • Controls and coordinates the CPU's activity
  • accepts the next instruction
  • decodes instruction
  • stroes resulting data in memory
  • manages the flow between the CPU and other devices
• What is the function of a register?


  A register is a small, memory cell that operates at high speed used to temporarily store data
• What is the function of the Program Counter?

  The PC holds the address of the next instruction to be executed
• What is the function of the Accumulator?

  The Accumulator stores results from calculations
• What is the function of the memory address register?

  The MAR holds the address of the location that is to be read from or written to
• What is the function of the Current Instruction Register?

  The CIR holds the current instruction being executed
• What are buses?

  Buses are parallel wires connected to 2 or more components of the CPU
• What are the 3 buses?

  • address bus
  • data bus
  • control bus
• What are the 3 buses collectively known as?

  System bus
• What is the function of the data bus?

  The data bus is bi-directional, and transports data and instruction to other components of the CPU
• What is the function of the address bus?

  The address bus transmits the memory address specifying where data is to be retrieved from or sent to
• What is the function of the control bus?

  The control bus transmits control signals to external and internal components. It also coordinates the use the address bus and the data bus.
• What is assembly language?

  Assembly language is a low-level prgramming language that uses mnemonics to represent instructions.
• What is opcde?

  Opcode determines what type of instruction it is and what hardware to use to execute it
• What is the operand?

  The operand is the actual data to be operated on, and the address of where the operation is performed.
• What happens during the fetch phase?

  • The address at the PC is copied to the MAR
  • Instruction held at that address is copied to the MDR by the data bus
  • PC increments by 1
  • The value of the MDR is copied to the CIR
• What happens during the decode phase?

  The contents of the CIR is split into the opcode and operand
• What happens during the execute phase?

  The opcode is executed onto the data
• What factors improve the performance of a processor?

  • increasing the number of cores
  • increasing clock speed
  • increasing cache size
  • pipelining
• What is clock speed?

  The number of clock cycles completed per second
• What is cache memory?

  The CPU's onboard memory which can be accessed a lot faster than main memory.
• What is pipelining?

  Pipelining is the process of completing the fetch, decode and execute of three separate files simultaneously.
• What is contemporary processing?

  Contemporary processing is a mix between the Von Neumann and Harvard Architecture
• What is the Von neumann Architecture?

  The architecture includes the basic components of a computer and processor in which a shared memory and data bus is used for both data and instruction
• What are the advantages of the Von Neumann architecture?

  • Cheaper to develop as the CU is easier to design
  • Programs can be optmised in size
• What is the Harvard architecture?

  The architecture has separate memories for instructions and data
• What are the advantages of the Harvard architecture?

  • Quicker execution as data and instructions can be fetched in parallel
  • Memories can be different sizes, which can make more efficient use of space
• What does RISC stand for?

  Reduced Instruction Set Computer
• What does CISC stand for?

  Complex Instruction Set Computer
• What are the proporties of RISC?

  • small instruction set
  • each instruction is one line of machine code
  • used in everyday devices
• What are the proporties of CISC?

  • A large instruction set
  • instructions are built into hardware
  • used in embedded systems and microprocessors
• What are the benefits of RISC proceesors?

  • Pipelining is possible since each instruction takes one clock cycle
• What are the benefits of CISC processors?

  • compilers have less work to do
  • They have/require less RAM since instructions are smaller
• What is a graphic processing unit and what are they used for?

  A GPU is a co-processor made up of lots of independent parallel processors. They are now used for image processing and machine learning
• What are multi-core systems?

  Systems where there are multiple cores that separate fetch-decode-execute cycles
• What are parallel systems?

  Systems where multiple instructions can be completed at any given time; doesn't require multiple cores, it can use threading or pipelining instead
• Give examples of input devices?

  • keyboard
  • mouse
  • microphone
  • webcam
  • touchpad
• give examples of tyes of magnetic storage?

  • Harddisk drive
  • floppy disk
  • magnetic disk
• Name a device which can be used for input and output?

  Touchscreen