Architecture of the CPU

Flashcards about the architecture of the CPU.

CPU

Central Processing Unit. The most important component of a computer.

Purpose of the CPU

Processes instructions, runs programs, and carries out billions of instructions per second.

Stored program concept

A concept where program instructions and the data the programs are using are both stored in the same memory.

Von Neumann architecture

Program instructions and data are stored in the same memory, and the CPU accesses both from the same RAM.

Two major components of the CPU

Control Unit and Arithmetic-Logic Unit (ALU)

Register

Very fast memory location in the CPU.

Cache

Located on the CPU, slower to access than registers but faster than RAM.

Program Counter (PC)

Holds the address of the next instruction to be executed.

Memory Address Register (MAR)

Holds the memory address of the current instruction and its data.

Memory Data Register (MDR)

Holds the actual instruction and the data fetched from memory.

Accumulator

Holds the result of an instruction before it's transferred to memory.

Control Unit (CU)

Decodes the instructions and controls the timing of operations in the CPU.

Arithmetic Logic Unit (ALU)

Performs arithmetic and logic operations.

FETCH

Causes the next instruction and data to be fetched from main memory.

DECODE

Decodes the fetched instruction.

EXECUTE

Executes the decoded instruction.

Accumulator (ACC)

Temporarily stores arithmetic and logic results.

Program Counter (PC)

Points to the next instruction.

Memory Address Register (MAR)

Stores the address of the instruction to be executed.

Memory Data Register (MDR)

Stores the data to be sent/received from memory

Comparison operation

Compares values and makes decisions based on conditions.

Addition operation

Adds numbers

Subtraction operation

Subtracts numbers

Multiplication operation

Multiplies numbers

Division operation

Divides numbers

Bus

A set of signals which carry data and instructions between components.

Front Side Bus (FSB)

Connects all the internal components of a computer such as CPU and memory to the motherboard.

HyperTransport Bus

Connects the CPU to the northbridge.

Memory Bus

Connects the CPU to RAM.

Inter-Component Bridge

Connects the northbridge to the southbridge.

Peripheral Component Interconnect (PCI)

Connects the southbridge to the PCI slots.

PCI Express (PCIe)

A high-speed serial connection that connects the CPU to peripherals.

Serial Advanced Technology Attachment (SATA)

Interface used to connect storage devices such as hard drives and solid-state drives to the computer.

Universal Serial Bus (USB)

A standard for connecting USB devices to the computer.