A constraint-driven methodology for placement of analog and mixed-signal integrated circuits

Layout design of analog and mixed-signal circuits is often a manual and time-consuming, trial-and-error task. Stringent constraints that must be considered simultaneously are a major reason why layout design is often not automated. To overcome this bottleneck in the design process, we present a new constraint-driven design methodology. We have verified our methodology by applying it to the placement of both analog and mixed-signal circuits. Our approach allows us to verify whether a solution that satisfies all constraints exists prior to the time consuming optimization process. If a solution exists, an initial placement with a maximum constraint robustness is constructed. Next, the initial placement is optimized. Unlike the optimization engines known so far, our implementation is driven not only by the placement objectives, but also by the adaptively weighted constraints. This allows efficient searching in the solution space of the constraints.