Debug, Compliance, and Performance

Section goal

Protocol analyzer workflows, LTSSM debug, compliance test plans, and performance tuning for PCIe/CXL systems.

This section trains how to reason from symptoms to PCIe/CXL mechanism, then close with owner accountability, reliability gates, and release-safe decisions.

How to study this section

1. Start with each topic hub and draw the mechanism path.

2. Use reports and debug pages to prove causality before tuning.

3. Practice worked examples and interview drills with explicit evidence chains.

4. Close each topic with checklist and silicon impact pages.

Topics

1. protocol-analyzer-workflow/ - Protocol Analyzer Capture and Triage

2. ltssm-debug/ - LTSSM State Machine Debug

3. compliance-test-plans/ - PCI-SIG and CXL Compliance Testing

4. performance-tuning/ - PCIe/CXL Performance Tuning

Related topics

• PCIe/CXL Deep Dive course hub

PCIe/CXL deep dive

Debug and compliance turn protocol knowledge into reproducible signoff with analyzer discipline and regression gates.

Concept diagram

DEBUG CLOSURE LOOP

trigger capture -> hypothesis -> bounded fix -> compliance/perf replay

Metric graph

TRIAGE TIME SHARE

LTSSM/PHY           ██████
TLP/credit          ████
enumeration         ███

Reports and artifacts

• analyzer trace bundle

• LTSSM heatmap

• compliance matrix

• performance tuning changelog

Mini case study

Compliance pass at room temperature missed Gen5 EQ regression that appeared only in thermal chamber replay.

Debug branches

• Use error-qualified analyzer triggers

• Replay compliance subset on PHY/FW changes

• Tune MPS/MRRS against production traffic mix

Senior review question

Ask: which latency, bandwidth, and reliability evidence proves this PCIe/CXL topic is closed under real traffic?