CPU Structure & Instruction

Basic concepts about CPU components, instruction cycle, pipelines, and RISC concepts.

CPU

The Central Processing Unit; the brain of the computer that executes instructions.

ALU

Arithmetic Logic Unit; performs all calculations and logic operations.

Control Unit (CU)

Directs the flow of data and instructions in the CPU.

Registers

Small, fast storage inside the CPU for temporary data and instructions.

Cache Memory

Fast memory close to the CPU to store frequently used data.

Program Counter (PC)

Holds the address of the next instruction to execute.

Instruction Register (IR)

Holds the instruction currently being executed.

Fetch Stage

CPU retrieves an instruction from memory.

Decode Stage

CPU interprets what the instruction means.

Execute Stage

CPU performs the operation specified by the instruction.

Store Stage

CPU writes the result back to memory or a register.

Pipeline

Technique where multiple instruction stages overlap to speed up processing.

Pipeline Hazard

Problem that slows down a pipeline, like data or control conflicts.

RISC

Reduced Instruction Set Computer; CPU with simple instructions for faster execution.

CISC

Complex Instruction Set Computer; CPU with complex instructions that take longer.

Interrupt

Signal that pauses CPU to handle important tasks immediately.

Clock Speed

How fast the CPU can process instructions, measured in GHz.

Bus

Pathways for data and instructions between CPU, memory, and devices.

Control Signals

Signals sent by the control unit to manage CPU operations.

Instruction Cycle

Sequence of steps (Fetch → Decode → Execute → Store) the CPU follows to run instructions.