What you'll learn

CHI scales coherency to many cores with separate request, response, data, and snoop networks.

• CHI nodes: RN (Requester), HN (Home), SN (Subordinate); establish each node's supported capabilities.

• REQ, RSP, DAT and SNP separate message roles; progress still needs correct dependencies and resource handling.

• A coherent home may use a directory or snoop filter; do not assume every CHI system has one.

Connection

Compare ACE's channels with CHI's message roles. The specialist Cache Coherency course develops transient states and resource dependencies in depth.

Key diagram

CHI node roles, not a cycle budget

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