Incremental meta-data construction for VLSI design databases

VLSI design databases are typically based on object-oriented data models, which provide primitives for modeling and manipulating design objects and their inter-relationships. However, in practice it is rather difficult for end users (i.e. circuit designers) to understand these primitives, let alone interact with them directly. Unfortunately, existing systems assume that it is the user´s responsibility to explicitly build up the meta-data, by which is meant attribute and relationship information. This paper presents a novel incremental meta-data construction paradigm, which is based on (1) a structured design history model, and (2) the specifications of tool-specific execution semantics. Using this paradigm, the authors design and implement algorithms that automatically establish per-object attributes and inter-object relationships as a side effect of CAD tool execution. Consequently the rich modeling capability of an object-oriented database can be fully exploited in a design environment without circuit designers´ participation in meta-data construction