Characteristics of contemporary processors

Central Processing Unit (CPU)

The CPU carries out instructions in computer programs, consisting of the arithmetic logic unit, control unit, and registers.

Arithmetic Logic Unit (ALU)

The ALU performs calculations and logical decisions, with results stored in the accumulator.

Control Unit (CU)

The CU coordinates how the processor works, controls data movement within the CPU and between CPU and memory, and decodes instructions.

Registers

Areas of memory within the processor accessed at high speeds, including special purpose registers like Program Counter (PC), Memory Data Register (MDR), Memory Address Register (MAR), Current Instruction Register (CIR), and Accumulator (ACC).

Program Counter (PC)

Keeps track of the memory location of the current instruction being executed, allowing programs to run sequentially by pointing to the next instruction.

Memory Data Register (MDR)

Stores data or instructions to be fetched from or sent to memory.

Memory Address Register (MAR)

Stores the address of data or instructions to be fetched from or sent to memory.

Accumulator (ACC)

Stores results of calculations by the ALU, holding the most recently fetched instruction for decoding and execution.

Register

A discrete memory unit on the CPU holding a single data piece. They can be accessed at high speeds so they can be used by the processor without causing a bottle neck.

Current instruction register

Stores the most recently fetched instruction, which will be decoded and executed.