Alevel CS Key Terms 1-20

“The part of the CPU where data is processed and manipulated.  This processing and manipulation normally consists of arithmetic operations or logical comparisons allowing a program to make decisions.”

• Arithmetic Logic Unit

• Control Unit

• Register

• Program Counter

The part of the CPU that manages the execution of instructions. The control unit fetches each instruction in sequence, and decodes and synchronises it before executing it by sending control signals to other parts of the computer

• Arithmetic Logic Unit

• Control Unit

• Register

• Program Counter

“Tiny areas of extremely fast memory located in the CPU normally designed for a specific purpose, where data or control information is stored temporarily.”

• Arithmetic Logic Unit

• Control Unit

• Register

• Program Counter

A register in the control unit which holds the address of the next instruction to be executed.”

• Arithmetic Logic Unit

• Control Unit

• Register

• Program Counter

“A special register within the ALU.  It is used to hold the data currently being processed by the central processor.  Any data to be processed is stored temporarily in the accumulator, the results ending up back in the accumulator being stored in the memory unit.”

• Arithmetic Logic Unit

• Control Unit

• Accumulator

• Program Counter

A register in the CPU that stores the address of the memory location currently in use.  In the fetch phase, this would be the address of the instruction being loaded; in the execute phase, it would be the address of the data being used

• Arithmetic Logic Unit

• Memory Address Register

• Accumulator

• Program Counter

A register in the CPU that stores data being transferred to and from the immediate-access store. It acts as a buffer, allowing the central processor and memory unit to act independently without being affected by minor differences in operation. A data item will be copied to the MDR ready for use at the next clock pulse, when it can either be used by the central processor or be stored in main memory

• Memory Data Register

• Control Unit

• Accumulator

• Program Counter

A register in the control unit that stores the address of the next instruction currently being executed and decoded

• Memory Data Register

• Current Instruction Register

• Accumulator

• Program Counter

A common physical pathway shared by signals to and from several components of a computer

• Memory Data Register

• Current Instruction Register

• Accumulator

• Buses

The part of the bus which carries the actual information

• Address Bus

• Current Instruction Register

• Data Bus

• Buses