1.1 GCSE Computing: CPU Components

Front

Register containing the address of the currently executing instruction.

Back

PC (Program Counter)

Front

Stores the address for data fetching or storage.

Back

MAR (Memory Address Register)

Front

Holds the instruction being processed or executed

Back

CIR (Current Instruction Register)

Front

Calculates: addition, division, multiplication, subtraction

Back

ALU (Arithmetic and Logic Unit)

Front

Data being transferred to/from memory.

Back

MDR (Memory Data Register)

Front

Stores results of calculations in progress

Back

Accumulator

Front

STORED PROGRAM CONCEPT: Computers...

Back

Can store data and instructions anywhere within memory.

Front

The CPU is...

Back

The part of a computer that processes instructions.