4.2.3: understand the concept of a stored program and the role of components of the CPU (control unit (CU), arithmetic/logic unit (ALU), registers, clock, address bus, data bus, control bus) in the fetch-decode-execute cycle (the Von Neumann model)
Keyword | Definition |
---|---|
Address bus | connections between the CPU and other components to transmit the location of data / instructions being written or read |
Arithmetic Logic Unit | Performs maths calculations and comparisons to carry out instructions |
Clock | an electronic signal that keeps changing from on to off at a constant rate to keep each part of the CPU in sync |
Control bus | connections between the CPU and other components to transmit signals that trigger each stage of the fetch-decode-execute cycle |
Control Unit | part of the CPU that controls all of the other components. |
Data bus | connections between the CPU and other components to transmit the value of data / instructions being written or read |
Decode | Using the control unit to understand the current instruction and work out how to follow it |
Execute | Using the ALU to run the current instruction |
Fetch | Getting an instruction from main memory into the registers inside the CPU |
Registers | Very fast memory locations used in the fetch-decode-execute cycle to store tiny amounts of data or single instructions |
Von Neumann | a type of CPU design model where data and instructions are both saved in the same memory store |