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Computer Science IGCSEPDF 21
142 pagesrevision 46930
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Hence
■ CPUfetches, decodes and executes instructions.
■ Microprocessors are physical chips that contain CPU.
■ Theyare like Head (Microprocessor) and Brain (CPU).
Von Neumman Architecture
Von Neumann Architecture is a design of CPU proposed by
Mathematician John Von Neumann.
It describes how computer's memory, input/output devices, and
processor function together.
It is made up of:
○ Control Unit (CU)
■ Manages data flow within the CPU by sending
control signals to direct its movement.
■ Interprets the instructions retrieved from memory.
Arithmetic Logic Unit (ALU)
Carries out arithmetic calculations.
Executes logical operations and decisions.
Registers
Registers are extremely small and incredibly fast
memory units located within the CPU.
They temporarily store small amounts of data
required during the fetch-execute cycle.
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