Topic 2 organisation Flashcards
Define CPU
The “brain of the computer system” that can process data very quickly but can only process data by following instructions, meaning it cannot think for itself
List what the CPU contains (4)
Control Unit (CU)
Arithmetic Logic Unit (ALU)
Memory Address Register (MAR)
Memory Data Register (MDR)
Define control unit (3)
Component of CPU that is responsible for the operation of the CPU
Controls the retrieval of instructions from the primary memory as well as the sequence of of their execution.
The CU is responsible for providing the ALU with the data that needs to be processed as well as instructions on how the data should be processed
Define ALU
performs all the basic arithmetic instructions, logical or input/output operations
What does MAR do (2)
The MAR holds the memory location address that is about to be written to, so that the ALU can fetch the corresponding content from the memory and process it accordingly
MAR also holds the memory address of where the data that has been processed will need to be stored
How does the MAR and primary memory communicate
Memory address bus
What does the MDR do
Holds the data that is to be used by the ALU
After processing has taken place, the ALU places the results onto the MDR and the data is copied onto the RAM
How is the MDR and MAR closely related
Whichever memory address location the MAR is holding, the corresponding data will be loaded onto the MDR for processing by the ALU
How does the MDR and primary communicate
Data bus
Define buses
Connecting wires that connect the CPU to other devices, carrying instructions to and from components
Name the 3 important buses (3)
Data bus (links primary memory and CPU via MDR)
Control bus (links primary memory and CPU via control bus)
Memory address bus (links primary memory and CPU via MAR)
