Richard H. Lathrop, Robert S. Kirk
Focusing especially on the later stages of the design task, when a complete (or nearly so) design is being optimized at the structural level prior to final physical layout, we identify some aspects of the VLSI domain which complicate efficient design both for human and machine agents. We describe a simple but useful idea and a prototype implemented system which partially addresses these problems. Examples are conveyed graphically from an existing design. The system automatically learns a design precedent enabling it to infer local hierarchy corresponding to the example in new designs. The teacher may also substitute alternative actions, described to the system in its native Y hardware description language, which the system remembers and can also apply later. CONSTELLATION can infer local hierarchy; undo and rationalize clever local tricks and work-arounds; search for situations in which a specific local optimization can be applied; and modify the circuit as described by the teacher. The system is in experimental use in a production environment.