1.1 – Systems architecture

The CPU executes instructions in order to run programs and contains an arithmetic logic unit - a control unit - and numerous registers

Performs mathematical calculations and logical operations as required

Marshals and controls the operation of the fetch-execute cycle coordinating the CPU and sending commands to other components for example requesting the ALU to perform a calculation

Small fast memory located on the CPU that stores frequently used data and instructions to improve performance

Fast-to-access storage locations used to store small amounts of data temporarily during CPU processing

Stores the address of the data to be fetched from or the address where the data is to be stored

Stores the data being fetched from or written to memory acting as a buffer between main memory and the CPU

Stores the address of the next instruction to be fetched from memory and increments during each fetch-execute cycle

Stores the results of calculations or operations carried out by the ALU and temporarily holds data being processed

Continuous cycle performed by the CPU where instructions are fetched from memory decoded and executed repeatedly

Address of next instruction transferred from Program Counter to MAR - instruction fetched into MDR - Program Counter incremented - instruction decoded by CU - instruction executed by CPU or ALU - cycle repeats

CPU model where instructions and data are stored in the same memory

The frequency at which a clock sends electrical signals controlling the number of instructions executed per second - higher clock speeds increase CPU performance

Larger cache stores more frequently used data reducing access to slower RAM and improving CPU performance

Multiple cores allow the CPU to process more instructions simultaneously improving performance but not all programs can utilise multiple cores

A computer system designed to perform specific dedicated functions within a larger device

Designed for specific tasks - built into devices and not easily separated - minimal or no user interface - optimised for efficiency and reliability - typically low power small and efficient

Washing machines controlling water temperature cycle timing and motor speed - Microwave ovens managing cooking time power levels and safety features - Traffic lights controlling timing sequences and responding to sensors