Structuring & Buffering: Reports & Metrics

Reports and metrics

Reports & Metrics for Structuring & Buffering focuses on logic depth, fanout violations, buffer count, slew violations. The goal is to connect observed QoR movement to mechanism, ownership, and regression risk.

A report is useful only when it supports decisions. For Structuring & Buffering, read metric movement with baseline context and expected budget.

Metric movement

QOR TREND — Structuring & Buffering

metric quality
  ^
  |                      target band
  |                o  o  o
  |            o
  |      o  regression
  +----------------------------------> synthesis iteration
   baseline    tuning     signoff-ready

Track: logic depth, fanout violations, buffer count, slew violations

• Track logic depth, fanout violations, buffer count, slew violations with exact run manifests.

• Keep timing/area/power side-by-side in review dashboards.

• Require one-sentence mechanism hypothesis for every major delta.

• Store before/after artifacts with owner signoff.

Synthesis deep dive

Mapping converts logic intent into real PPA outcomes.

Concept diagram

MAPPING LOOP

boolean net -> library mapping -> optimization -> report and iterate

Metric graph

MAPPING IMPACT

depth reduction   ███████
fanout cleanup    █████
runtime overhead  ███

Reports and artifacts

• mapping summary

• critical path cell list

• fanout/slew report

• library coverage

Mini case study

Cell-heavy critical path improved after restructuring, while blanket buffering had worsened power.

Debug branches

• Depth issue -> structure

• Fanout issue -> buffers

• Library mismatch -> view audit

Senior review question

Ask: what evidence proves this QoR move is real and stable?

Key takeaways

• State exact run context (RTL, SDC, libs, switches) with every QoR claim.

• Re-run timing, area, and power regressions after each synthesis ECO.

Common pitfalls

• Comparing runs with mismatched constraints or library views.

• Timing-only fixes that violate power or area budgets.

• Skipping equivalence checks after structural changes.

Report reading lens