Presentation
Late Breaking Results: 3D Analytical Placement with Smoothed Multi-Die Wirelength Model
DescriptionHeterogeneous integration via hybrid bonding optimizes power, performance, and area (PPA) in multi-die systems. A core challenge is assigning circuit blocks to dies in different process technologies. Existing analytical formulations employ smoothly varying sigmoid proxies, causing assignment oscillation, or hard step functions that undermine robustness. We introduce a soft die indicator based on a piecewise-smooth surrogate with a strategically scheduled gradient decay, preserving early differentiability while progressively sharpening decisions. Building on this indicator, we develop (i) a smoothed multi-die wirelength model considering pins on both inside and on net bounding boxes to guide optimization precisely, unlike most previous models considering only pins on the boxes, and (ii) a size-compensated density formulation for heterogeneous dimensions. An adaptive preconditioner further balances gradients between macros and standard cells. Experimental results on the 2023 ICCAD CAD Contest benchmarks show that our placer achieves the smallest inter-die wirelength and fastest runtime among published academic placers.
Event Type
Late Breaking Results
TimeMonday, July 276:47pm - 6:50pm PDT
LocationExhibit Hall