Async FIFO CDC: Reports & Metrics

Reports and metrics

Reports & Metrics for Async FIFO CDC focuses on overflow/underflow risk, pointer synchronization integrity, latency throughput. The goal is to convert issue observations into mechanism-backed closure decisions.

Reports must explain risk movement in overflow/underflow risk, pointer synchronization integrity, latency throughput, not just issue counts. A report is complete only when ownership and closure action are explicit.

Metric movement

METRIC TREND — overflow/underflow risk, pointer synchronization integrity, latency throughput

critical open issues
  ^
  |                target (0 critical)
  |              - - - - - - - - - -
  |          o post triage
  |      o initial run
  |   o baseline
  +--------------------------------------> review iteration

Always pair count trend with evidence quality trend.

Risk distribution

RISK HEATMAP — Async FIFO CDC

severity
high   |  XX  X
medium |  XXX XX
low    |  XXX XXX
        +----------------------------> ownership readiness
         unassigned   in-progress   closed

Metric focus: overflow/underflow risk, pointer synchronization integrity, latency throughput

• Track overflow/underflow risk, pointer synchronization integrity, latency throughput by block, mode, and severity.

• Separate structural warnings from behavior-proven hazards.

• Show waiver age and owner SLA alongside raw counts.

• Store evidence links with each closure claim.

CDC/RDC deep dive

Protocol correctness is the bridge between structural clean and functional safe.

Concept diagram

PROTOCOL FLOW

intent -> transport protocol -> synchronization -> destination acceptance

Metric graph

PROTOCOL ISSUE BURNDOWN

open issues: 20 -> 11 -> 5 -> 0

Reports and artifacts

• FIFO pointer proofs

• req/ack liveness

• pulse miss checks

• protocol assertions

Mini case study

Async FIFO empty/full logic looked correct until gray decode mismatch appeared during reset overlap.

Debug branches

• Pointer sync audit

• formal liveness checks

• reset interaction review

Senior review question

Ask: what evidence proves this risk is closed for silicon, not just tool-clean?

Key takeaways

• State crossing class, assumptions, and owner with every issue.

• Run structural and dynamic regressions after each fix.

Common pitfalls

• Treating all warnings as equivalent risk.

• Waiving issues without containment evidence.

• Skipping reset and reconvergence stress after CDC fixes.

Reading evidence