Late RTL changes rarely justify a full re-run. Incremental compile re-optimises the affected cone, and an ECO patches the netlist with spare cells and rewiring, with equivalence re-proven after every patch.
Lesson | What it covers |
|---|---|
When a late change needs a full re-run and when a patch is enough. | |
Finding the cone of a changed output with a runnable Python model. | |
Spare cells, rewiring, and resizing, with Yosys count checks over disjoint cones. | |
How preserved boundaries trade stability against quality of results. | |
Re-proving equivalence after an ECO and checking QoR guardbands. |
When the change spreads beyond one cone, when spare cells run out, or when QoR after the patch misses the target the full flow would meet.