Comp T1

• What is the main function of the Central Processing Unit (CPU)?


  To execute instructions
• What are the main components of the CPU?

  • Control Unit
  • Buses
  • ALU (Arithmetic/Logic Unit)
  • Dedicated registers
• What is the role of the Control Unit in the CPU?


  It controls and coordinates the activities of the CPU and directs data flow.
• What does the Control Unit do with the next instruction?


  It decodes it into several sequential steps and manages its execution.
• What is a bus in computer architecture?


  A set of parallel wires connecting components of a computer.
• What are the three types of buses that connect the CPU to main memory?

  Address bus, data bus, and control bus.
• What is the function of the address bus?


  It sends the address of the memory location the CPU wishes to access.
• How does the data bus function?


  It returns data from a specified memory location to the CPU.
• What is the purpose of the control bus?


  To transmit command, timing, and specific status information between system components.
• What type of bus is the control bus?


  Bi-directional
• What is the significance of the data bus being bi-directional?


  It allows data and control signals to travel both to and from the CPU.
• What is the role of the Arithmetic Logic Unit (ALU)?


  To perform arithmetic and logical operations on data.
• What is the accumulator in the context of the ALU?


  A register that stores the results of arithmetic or logical operations.
• What are the different types of registers in the CPU?

  • PC (Program Counter): Holds the address of the next instruction.
  • CIR (Current Instruction Register): Holds the current instruction being executed.
  • MAR (Memory Address Register): Holds the address of the memory location for data.
  • MDR (Memory Data Register): Stores data read from or written to memory.
• What are the phases of the Fetch Decode Execute Cycle?


  1. Fetch: Copy address from PC to MAR, retrieve instruction to MDR, increment PC.
  2. Decode: Split instruction into opcode and operand.
  3. Execute: Carry out operation based on opcode and operand.
• What factors affect CPU performance?


  Clock speed, number of cores, and cache size/type.
• How is clock speed measured?


  In Hertz (Hz)
• What is the impact of increasing clock speed on CPU performance?


  It allows more instructions to be executed per second.
• How do multi-core processors improve performance?


  They can execute multiple instructions simultaneously.
• What is cache memory?


  Fast memory inside the CPU that stores frequently accessed data.
• What is pipelining in CPU architecture?


  A process that allows overlapping of instruction fetch, decode, and execute stages.
• What are the key differences between Von Neumann and Harvard architecture?


  • Von Neumann: Shared memory for data and instructions, single bus.
  • Harvard: Separate memories for data and instructions, multiple buses.
• What is contemporary architecture in CPUs?

  A mix of Von Neumann and Harvard architectures with shared main memory and divided cache.
• What are the characteristics of CISC architecture?


  • Large instruction set
  • Complex instructions
  • Load/store functions incorporated
  • Short programs requiring less RAM
• What are the characteristics of RISC architecture?


  • Few instructions in the instruction set
  • Simple instructions executed
  • Load/store specified
  • More work for compilers, but eligible for pipelining
• How do GPUs differ from CPUs?


  GPUs have thousands of smaller cores for parallel processing, while CPUs have fewer cores optimized for serial processing.
• What is the role of a GPU as a co-processor?


  To accelerate processing by offloading intensive tasks from the CPU.