Pipelining

Understanding instruction pipelining and hazards in computer architecture

Introduction

Pipelining is a technique used in computer architecture to improve instruction throughput by overlapping the execution of multiple instructions.

Pipeline Stages

Typical pipeline stages in a RISC processor:

  1. Instruction Fetch (IF)
  2. Instruction Decode (ID)
  3. Execute (EX)
  4. Memory Access (MEM)
  5. Write Back (WB)

Pipeline Hazards

Types of pipeline hazards:

  • Data Hazards
    • RAW (Read After Write)
    • WAR (Write After Read)
    • WAW (Write After Write)
  • Control Hazards
    • Branch Prediction
    • Branch Target Buffer
  • Structural Hazards
    • Resource Conflicts
    • Memory Access Conflicts

Pipeline Performance

Key performance metrics:

  • Pipeline Throughput
  • Pipeline Latency
  • Pipeline Efficiency
  • Speedup Factor

Important Concepts

Key aspects of pipelining:

  • Pipeline depth and width
  • Hazard detection and resolution
  • Forwarding and bypassing
  • Branch prediction techniques
  • Pipeline scheduling