1.1

• CPU components

  ALU, registers, CU, Accumulator, cache
• CU

  Control Unit manages the execution of instructions using control signals to coordinate how the processor works and how data moves between the CPU and the memory. Uses control signals to coordinate FDE cycles and decode instructions.
• ALU

  Arithmetic Logical Unit controls all arithmetic and Boolean calculations and processes that are required for an FDE cycle. Results are stored in the accumulator.
• Registers

  Registers are small fast specific memory locations on the CPU that make storing and fetching data for FDE cycles quicker and faster than retrieving and storing data in RAM.
• PC

  Program Counter stores the next instruction to be fetched and passed to RAM. Is altered to the address from the instruction in CIR if operations receives a JUMP instruction.
• MAR

  Memory Address Register stores the address of the instruction that is about to be decoded.
• MDR

  Data fetched from the address stored in the MAR is stored in the MDR.
• CIR

  Current Instruction Register stores most recently fetched instruction while it is being decoded and executed.
• Opcode

  When decoded, tells the CU what actions need to be taken.
• Operand

  The data which will have the code that will be subject to the opcode.
• Accumulator

  Stores the results of any process, ALU calculation or instruction.
• Bus

  Set of wires on the motherboard that carry data between the CPU, RAM and the registers.
• Data Bus

  Carries data transmitted from one register to another between processor and memory.
• Address Bus

  Carries memory location addresses of the register data is being read from/written to.
• Control Bus

  Transmits control signals for the CU to allow synchronisation of signals to the rest of the processor.
• FDE Cycle

  Instruction in PC is moved to MAR. Data stored at address in MAR is fetched and stored in the MDR. PC increments by 1.

  Data in MDR is moved to CIR and is decoded. The data is separated into opcode and operand. The opcode tells the CU what actions are required by the CU for the instruction to be executed.
• Clock Speed

  Controls process of executing instructions and fetching data. Overclocking leads to more cycles per second so more instructions are executed so the program takes less time to run. Increased performance but also produces heat for additional cooling necessary to prevent CPU damage.
• Cores

  Distinct processing units on the CPU that can run different apps when multitasking or multiple cores processing a small problem can speed up the process.
• Cache Memory

  Small fast memory located on the CPU, used to store small frequently used data and instructions. Overall speed is increased and it is quicker for future use as RAM is accessed less frequently.
• Pipelining

  While one instruction is being executed, the next is being decoded and the next is being fetched.
• Von Neuman

  Single processor. Data/Instructions are stored together in the same memory. Simple and easy to program but slower at processing large sets of data.
• Harvard

  Data/Instructions are stored in separate memory units with separate buses so while data is being read from/written to data memory, next instruction can be read from instruction memory