Specification (spec)
Beginner
The written list of everything a chip must do and the limits it must stay within, agreed before anyone designs it.
Novice
The set of documents that turns a product idea into numbered, measurable requirements: what the chip must do, how fast, how much power it may use, how big and costly it may be, what it must connect to, and which test, safety and security rules it must meet. Every later stage is checked against it.
Expert
A controlled, versioned baseline: requirements with IDs, numeric targets, the conditions each applies under and the way each will be verified, plus the architecture and block-level specs derived from them. After it is frozen, changes go through a formal review, because each one ripples into the design code, the verification plan, the physical layout and the schedule.
Explained in Specification (Design Flow).
See also: Requirement (“shall” statement), Requirements traceability.