# CASCoDe

The bottleneck in analog layout automation is not any single tool but the missing, revisable coordination between sizing and physical structure. CASCoDe organizes sizing candidates, floorplan form, intra-row refinement and routing attempts into a hierarchical discrete action space, and an LLM agent runs feedback-guided tree search over it using post-extraction electrical results. On 20 SKY130 amplifiers it is the only flow that delivers a DRC- and LVS-clean routed layout for every circuit, cutting area by 59–85% (mean 71%) against APPlace on identical PCells.

The bottleneck in analog layout automation is not any single tool but the missing, revisable coordination between sizing and physical structure. CASCoDe organizes sizing candidates, floorplan form, intra-row refinement and routing attempts into a hierarchical discrete action space, and an LLM agent runs feedback-guided tree search over it using post-extraction electrical results. On 20 SKY130 amplifiers it is the only flow that delivers a DRC- and LVS-clean routed layout for every circuit, cutting area by 59–85% (mean 71%) against APPlace on identical PCells.