What you'll learn

Coherency bugs are the hardest protocol bugs — they need transaction ID, cache line, and state transition correlation.

• Correlate snoop transactions with the triggering coherent access.

• Litmus tests exercise model-specific ordering outcomes; passing a finite suite is not proof of all ordering behaviour.

• Deadlock requires a persistent wait/resource-dependency cycle under the stated progress assumptions; distinguish it from backpressure, starvation and livelock.

Connection

Debug synthesis of ACE, CHI, and cache maintenance topics.

Key diagram

A resource cycle needs an escape

Study this topic

1. Concepts — rules and mental models

2. Integration — system contracts

3. Debug — trace the first divergence

4. Interview — explain and defend your answer