Incremental & ECO Synthesis

Section goal

Incremental compile, netlist patching, equivalence hooks, and ECO regression governance.

How to study this section

1. Start with each topic hub to understand mechanism and ownership.

2. Use reports and debug pages to build run-comparison instincts.

3. Use interview and case pages for pressure drills.

4. Close with checklist and PPA impact before merge decisions.

Topics

1. incremental-compile/ — Incremental Compile

2. eco-netlist-patches/ — ECO Netlist Patches

3. equivalence-hooks/ — Equivalence Hooks

4. eco-regression/ — ECO Regression Discipline

Related topics

• Synthesis course hub

Synthesis deep dive

Incremental and ECO synthesis protect schedule only with strict regression discipline.

Concept diagram

INCREMENTAL ECO LOOP

identify delta -> localized compile -> patch -> regression -> release

Metric graph

ECO CYCLE TIME

full compile      ███████████
incremental       █████

Reports and artifacts

• incremental reuse

• ECO patch list

• LEC status

• regression matrix

Mini case study

Localized compile cut turnaround 40%, but skipped LEC caused rollback.

Debug branches

• Reuse ratio is not enough

• Patch locality check

• Always include equivalence hooks

Senior review question

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