CPU Structure & Instruction Flashcards

CPU (Central Processing Unit)

The "brain" of the computer that carries out instructions of a program.

ALU (Arithmetic Logic Unit)

The part of the CPU that performs mathematical and logical operations.

Register

High-speed storage locations inside the CPU used to hold data temporarily.

Program Counter (PC)

A register that holds the address of the next instruction to be executed.

Instruction Register (IR)

Stores the actual instruction currently being decoded or executed.

Fetch Stage

The first step of the cycle: getting the instruction from memory

Control Unit (CU)

Directs the operation of the processor and coordinates hardware components.

Decode Stage

Translating the fetched instruction into signals the CPU understands

Execute Stage

Carrying out the required action, such as a calculation or data move.

Write-Back Stage

Saving the result of an execution back into memory or a register

Pipelining

A technique where multiple instructions are overlapped during execution.

Pipeline Hazard

A situation that prevents the next instruction from executing in the designated clock cycle

Data Hazard

Occurs when an instruction depends on the result of a previous instruction that isn't finished

Structural Hazard

When two instructions need to use the same hardware resource at the same time.

Control Hazard

Caused by delay in determining the next instruction to fetch (often due to branches)

RISC (Reduced Instruction Set Computer)

A CPU design focused on simple instructions that execute in a single cycle

CISC (Complex Instruction Set Computer)

A CPU design where single instructions can perform multi-step operations.

Clock Speed

The speed at which a microprocessor executes instructions, measured in GHz.

Bus

A communication system that transfers data between components inside the computer.

Cache Memory

Small, very fast memory used to store frequently accessed data for the CPU.