Golden (signoff-quality) tool
Beginner
A checking program whose answer the factory and the design team trust enough to bet a chip on.
Novice
A checking tool whose answer is accepted as final, for example on timing or on the factory’s drawing rules. Earlier tools make estimates while they build the layout; a golden tool gives the verdict before the design goes to the factory.
Expert
Golden status rests on agreement with measured silicon and a long track record, which can only be earned after chips are made. A flow without golden tools has to guardband: add safety margin to its estimates so the design stays safe, at some cost in speed, power or area (PPA).