Structure & Function of the Processor (OCR A-Level Computer Science): Flashcards
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Practise the cards
13 cards from this deck
ALU's two main types of operations
ALU's two main types of operations
Arithmetic (e.g., +, -) & logic (e.g., AND, OR)
Fetch-decode-execute phase where ALU operates
Fetch-decode-execute phase where ALU operates
Execute phase
CU's main role in the CPU
CU's main role in the CPU
Directs & coordinates CPU activities via control signals
What the Control Unit decodes
What the Control Unit decodes
Instructions
What registers are in the CPU
What registers are in the CPU
Small, fast storage locations within CPU
What PC (Program Counter) holds
What PC (Program Counter) holds
Memory address of next instruction to execute
What ACC (Accumulator) stores
What ACC (Accumulator) stores
Data being processed by ALU & intermediate results
What MAR (Memory Address Register) holds
What MAR (Memory Address Register) holds
Memory address of data/instruction being fetched or stored
What MDR (Memory Data Register) stores
What MDR (Memory Data Register) stores
Data being transferred to/from memory
What CIR (Current Instruction Register) holds
What CIR (Current Instruction Register) holds
Current instruction being executed
Data bus: direction & purpose
Data bus: direction & purpose
Bidirectional; carries actual data between CPU & memory
Address bus: direction & purpose
Address bus: direction & purpose
Unidirectional; carries addresses from CPU to memory
Control bus purpose
Control bus purpose
Carries control signals from CU to coordinate CPU activities