Summary

• What is the purpose of the CPU in a computer?

  It is the most important part of the computer that does all the processing.
• What are the main functions of the CPU?

  It fetches, decodes, and executes instructions stored in main memory (RAM).
• What does CPU stand for?

  Central Processing Unit
• What does the FETCH operation in the CPU do?

  It causes the next instruction or any data to be fetched from memory.
• What is the purpose of the DECODE operation in the CPU?

  It decodes the instruction.
• What does the EXECUTE operation in the CPU do?

  It carries out the instruction.
• What components does the CPU contain?

  Arithmetic Logic Unit (ALU) and Control Unit (CU)
• How does clock speed affect CPU performance?

  A higher clock speed means the CPU can perform more fetch, decode, execute cycles per second.
• How is clock speed measured?

  In Hertz (Hz)
• What does 1 GHz represent in terms of CPU cycles?

  1 GHz equals 1,000,000,000 cycles per second.
• What is the role of cores in a CPU?

  Cores act like additional CPUs, allowing for parallel processing and multitasking.
• What is cache in relation to the CPU?

  Cache is small, fast, expensive memory that stores frequently used instructions.
• Why is cache faster than RAM?

  It is faster to transfer data to and from cache than to and from RAM.
• How does cache size affect CPU performance?

  • More cache can improve performance.
  • Cache is closer than RAM.
  • It stores frequently used instructions.
• Why might a quad-core processor not run twice as fast as a dual-core processor?

  Some programs do not utilize multiple cores, and other factors like clock speed and cache size also affect performance.
• What are the main components of the CPU and their functions?

  1. Control Unit (CU) - Coordinates the fetch-decode-execute cycle.
  2. Arithmetic Logic Unit (ALU) - Performs mathematical and logical calculations.
  3. Registers - Small fast storage for specific values.
  4. Cache - Stores frequently used instructions.
• What are the steps in the Fetch Decode Execute cycle?

  1. Copy contents of Program Counter (PC) to Memory Address Register (MAR).
  2. Increment the Program Counter by one.
  3. Fetch data across the address bus.
  4. Signal down the control bus.
  5. Bring instruction down the data bus and store in Memory Data Register (MDR).
  6. Control Unit decodes the instruction.
  7. ALU calculates the result.
  8. Store result in Accumulator.
  9. Execute the instruction.
• What are embedded systems?

  • Computer systems built into larger machines.
  • Have limited functions.
  • Include a single microprocessor with RAM, ROM, and CPU.
  • Used to control devices with simple controls.
• What are general-purpose computers?

  • Computers where applications can be installed.
  • Have a broad range of functionality.
  • Examples include laptops, tablets, and smartphones.
• Why are embedded systems important for digital devices?

  They allow devices to perform specific functions, like controlling a dishwasher or communicating with a satellite.
• Can you give examples of embedded systems?

  Washing machines, microwaves, ovens, car lights, car window wipers, and satnavs.
• What is the function of the Memory Address Register (MAR)?

  It stores the location of where data is in the RAM.
• What does the Memory Data Register (MDR) do?

  It stores data once it is fetched from the RAM.
• What is the purpose of the Program Counter?

  It stores the location of the next instruction to be run.
• What does the Accumulator do in the CPU?

  It stores the result of the ALU's calculations.
• What is the role of the Control Unit in the CPU?

  It coordinates the fetch-decode-execute cycle and sends signals to the processor.
• How does the ALU contribute to the CPU's function?

  It performs mathematical and logical calculations, including addition, subtraction, and comparisons.