To understand and analyze the directory-based cache coherence protocol through interactive simulation, exploring how distributed coherence mechanisms maintain data consistency in large-scale multiprocessor systems while achieving better scalability than traditional bus-based approaches.

Learning Objectives

By the end of this experiment, students will be able to:

1. Understand Directory-Based Coherence Concepts

   • Explain the fundamental principles of directory-based cache coherence
   • Identify the key components: directory states, sharer vectors, and ownership tracking
   • Compare directory-based protocols with bus-based alternatives

2. Analyze Protocol Behavior

   • Trace the execution of read and write operations in directory-based systems
   • Understand cache-to-cache transfers and their performance implications
   • Observe how invalidation protocols maintain consistency across multiple processors

3. Evaluate Performance Characteristics

   • Assess the scalability advantages of directory-based coherence
   • Identify potential bottlenecks and their mitigation strategies
   • Analyze network traffic patterns and message overhead

4. Apply Knowledge to System Design

   • Determine appropriate coherence protocols for different system architectures
   • Evaluate trade-offs between implementation complexity and performance
   • Understand the role of directory organization in large-scale systems