What is the purpose of the CPU?
The Central Processing Unit executes instructions in order to run programs.
What does the Arithmetic Logic Unit (ALU) do?
Performs mathematical calculations and logical operations as required.
What does the Control Unit (CU) do?
Controls the fetch‑execute cycle, synchronising the CPU and sending commands to components.
What is cache?
A small, fast memory on the CPU that stores frequently used data and instructions.
What are registers?
Fast storage locations used to store small amounts of data needed temporarily by the CPU.
What is the function of the MAR (Memory Address Register)?
Stores the address of data to be fetched from or written to memory.
What is the function of the MDR (Memory Data Register)?
Stores the data being fetched from or written to memory.
What is the function of the Program counter?
Stores the address of the next instruction to be fetched; increments each fetch‑execute cycle.
What is the function of the accumulator?
Stores results of calculations/operations from the ALU and temporarily holds data being processed.
Give the stages of the fetch‑execute cycle.
Address moved from PC to MAR; instruction fetched to MDR; PC incremented; instruction decoded by CU; executed by CPU/ALU; process repeats.
What is Von Neumann architecture?
A system where instructions and data share the same memory and bus.
What does the clock do?
Sends a regular electrical signal at a fixed frequency to synchronise system components.
What is clock speed?
The number of fetch‑execute cycles the CPU can perform per unit time (hertz).
How does increasing cache size improve performance?
Increases likelihood that an instruction is in cache, reducing memory access time.
What is the benefit of having multiple CPU cores?
More cores let the CPU handle multiple tasks simultaneously, increasing speed.
What is an embedded system?
A computer system designed to perform specific, dedicated functions within a larger system.
Give three examples of what embedded systems could do inside a washing machine.
Control water temperature, cycle timing and motor speed.
