1.1 GCSE Computing: CPU Components

This register contains the address (location) of the instruction being executed at the current time

• MAR (Memory Address Register)

• MDR (Memory Data Register)

• CIR (Current Instruction Register)

• PC (Program Counter)

• ALU (Arithmetic and Logic Unit)

Either stores the address from which data will be fetched from the CPU, or the address to which data will be sent and stored.

• MAR (Memory Address Register)

• MDR (Memory Data Register)

• CIR (Current Instruction Register)

• PC (Program Counter)

• ALU (Arithmetic and Logic Unit)

Holds the instruction that is being processed (and translated) or executed

• MAR (Memory Address Register)

• MDR (Memory Data Register)

• CIR (Current Instruction Register)

• PC (Program Counter)

• ALU (Arithmetic and Logic Unit)

Performs calculations (i.e. addition, division, multiplication, subtraction)

• MAR (Memory Address Register)

• MDR (Memory Data Register)

• CIR (Current Instruction Register)

• PC (Program Counter)

• ALU (Arithmetic and Logic Unit)

Holds the data that is being transferred to or from memory.

• MAR (Memory Address Register)

• MDR (Memory Data Register)

• CIR (Current Instruction Register)

• PC (Program Counter)

• ALU (Arithmetic and Logic Unit)

Which of these ARE NOT parts of the CPU? (select as many as appropriate)

• Accumulator

• General Purpose Register

• Input Device

• PC (Program Counter)

• Output Device

Used to store the results of calculations while they are in progress

• Arithmetic and Logic Unit

• Program Counter

• Current Instruction Register

• Accumulator

• Memory Data Register

The STORED PROGRAM CONCEPT means that computers...

• Have specific memory locations for instructions and specific memory locations for data

• Can store data and instructions anywhere within memory

The CPU is....

• The part of a computer that inputs data

• The part of a computer that processes instructions

• The part of a computer that outputs data

• The part of a computer that permanently stores data

Which of the following components ARE part of the CPU?

• Input Devices

• Accumulator

• Main Memory

• Output Devices

• Arithmetic and Logic Unit