The AMBEATion AMS BE flow produces valid layouts, meaning that: i) all devices in the input netlist are placed somewhere; ii) the placement does not contain overlaps; iii) the distance between devices respects technological constraint, etc. Moreover, the Quality-of-Results (QoR) of the produced layouts in terms area occupation, utilization, and routability (measured for example by the cumulative Half-Perimeter Wire Length - HPWL) is comparable to the one of human layouts on simple circuits (with few tens of devices).
Layouts generated by expert human designers are still of superior general QoR, for example because they also consider extra constraints (e.g. signal integrity, electrical matching, etc) which the AMBEATion flow does not yet fully account for in its automatic optimization. However, it is important to remark that unsupported constraints in AMBEATion are not due to a technical limitation of the flow algorithms, but mostly for time reasons.
That said, the AMBEATion flow is now mature enough to provide designers with a “reasonable starting point”, automatically an in a very short time, on top of which they can apply manual refinements. This is possible also thanks to the export functionalities of the flow, which enable using the AMBEATion results within Synopsys Custom Compiler, thus also permitting the execution of the remaining physical design phases (routing, signoff). In summary, the flow fully achieves its original goal of providing a quick method for design space exploration and rapid production of multiple “good enough” valid solutions without manual intervention, which experienced designers can then refine with their expertise to achieve a higher QoR, rather than wasting their effort in initial and time-consuming design iterations.
On the other hand, the current AMBEATion results are more directly comparable with those generated by other similar state-of-the-art AMS auto-placer tools developed by collaborative research projects (ALIGN, MAGICAL, etc). In this regard, our flow’s latest release includes all fundamental components that are present also in those tools. Additionally, AMBEATion takes into account more realistic sets of constraints (e.g. considering the impact of bulk connections in topology recognition, and allowing for pocket sharing among devices during placement, or including specific flow steps to handle the full-digital blocks in a complex AMS design). Moreover, the AMBEATion flow is tested on a real-world industrial technology node from ST and on several netlist from a real industrial project, rather than on simple netlists and open-source PDKs. For this exact reason (different benchmark circuits and technology libraries) a direct quantitative comparison with existing auto-placers is not possible, but in terms of supported features, we believe that AMBEATion is currently beyond the academic state-of-the-art.
Lastly, AMBEAtion’s modular software organization simplifies extensibility and quick replacement and/or comparison of algorithms for each individual flow step (both classic and AI/ML based). As we believe that this is a significant advantage of our flow with respect to the state of the art, the consortium is currently considering the option of open-sourcing the AMBEATion flow (after removing all IP-sensitive technological information).
