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Leilei Jin

Publications and source records attributed to Leilei Jin.

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CSCO: A Backside-PDN-Aware Clock-Signal Co-Optimization Framework for Improved PPA

Backside power delivery networks (BSPDN) have emerged as a promising technology for advanced logic nodes to address IR-drop and PPA challenges. While BSPDN introduces additional routing resources on the backside, these resources are limited and must be carefully partitioned between clock and signal nets, creating a critical resource allocation tradeoff. Prior work either moves only the clock network or assumes a fixed clock tree and optimizes only signal nets, failing to explore the tradeoff space of backside resource allocation. Moreover, lacking frontside power-ground shielding, BSPDN introduces severe signal integrity (SI) degradation. We propose CSCO, a data-driven BSPDN-aware co-optimization framework that jointly allocates limited backside resources between clock and signal nets across frontside/backside layers. CSCO employs efficient search strategies to identify critical nets for backside routing without repeated evaluation, navigating the clock-signal allocation tradeoff to balance IR-drop, routing congestion, and PPA. The framework also leverages backside routing to mitigate coupling noise and crosstalk-induced SI issues. Experiments demonstrate improved WNS/TNS, frequency, and SI robustness without additional shielding overhead.

cs.CE

CLIP-3D: Closed-Loop Evaluation of Performance and Physical Constraints for 3D ICs

3D integration packs more power into a smaller footprint, so a candidate design's actual throughput depends on its layout: which macro sits on which tier, where the hot spot lands, and how cache geometry maps to access cycles. Architectural simulators like gem5 report IPC under idealized timing. They do not produce the per-block power map, the cache cycle counts, or the 3D layout that decide the realized billion-instructions-per-second (BIPS), so early-stage 3D-IC exploration selects designs without accounting for the effects that decide whether they throttle on silicon. We present CLIP-3D, a shift-left flow that exposes 3D layout-driven thermal, wire, and cache effects to early-stage architectural exploration before any sign-off tool is invoked. The first stage lifts an architectural configuration into a physical block representation: McPAT for per-block dynamic and leakage power, CACTI for cache geometry and access cycles, and a HotSpot-compatible 3D stack discretization. The second stage runs an analytical 3D thermal-aware floorplanner over that representation. The floorplanner objective embeds a closed-form sustained-frequency expression derived from the linearity of HotSpot's steady-state operator and the standard CMOS power-frequency decomposition. Cross-tier macro assignment and in-plane placement are co-optimized for the realized BIPS rather than for a half-perimeter wirelength (HPWL)-plus-temperature surrogate with hand-tuned weights.

cs.AR

AgenticPD: A Stage-Aware Agentic Framework for Physical Design QoR Optimization

Physical design quality-of-results~(QoR) optimization is hard and expensive. Choices made at one stage can help or hurt later stages. Each evaluation requires a costly EDA run through the full flow. While existing methods still treat optimization as flat parameter tuning or a LLM-based script generation task, we present AgenticPD, a stage-aware agentic framework for physical design QoR optimization. Instead of re-running the full flow after every trial, AgenticPD is organized around the stage boundaries of the physical design flow, where a Judge Agent navigates the search and stage-specialized agents make local decisions within their own stage using stage-local tools. Additionally, the agent harness in AgenticPD provides structured observations, execution history, and agent context management. As a result, the system can branch from prior intermediate states and reuse checkpoints to continue the optimization procedure, and every candidate is evaluated at the post-route signoff. Across these baselines, AgenticPD achieves strong post-route timing while remaining competitive in power and area.

cs.AI

R2G: A Multi-View Circuit Graph Benchmark Suite from RTL to GDSII

Graph neural networks (GNNs) are increasingly applied to physical design tasks such as congestion prediction and wirelength estimation, yet progress is hindered by inconsistent circuit representations and the absence of controlled evaluation protocols. We present R2G (RTL-to-GDSII), a multi-view circuit-graph benchmark suite that standardizes five stage-aware views with information parity (every view encodes the same attribute set, differing only in where features attach) over 30 open-source IP cores (up to $10^6$ nodes/edges). R2G provides an end-to-end DEF-to-graph pipeline spanning synthesis, placement, and routing stages, together with loaders, unified splits, domain metrics, and reproducible baselines. By decoupling representation choice from model choice, R2G isolates a confound that prior EDA and graph-ML benchmarks leave uncontrolled. In systematic studies with GINE, GAT, and ResGatedGCN, we find: (i) view choice dominates model choice, with Test R$^2$ varying by more than 0.3 across representations for a fixed GNN; (ii) node-centric views generalize best across both placement and routing; and (iii) decoder-head depth (3--4 layers) is the primary accuracy driver, turning divergent training into near-perfect predictions (R$^2$$>$0.99). Code and datasets are available at https://github.com/ShenShan123/R2G.

cs.CV

A Crosstalk-Aware Timing Prediction Method in Routing

With shrinking interconnect spacing in advanced technology nodes, existing timing predictions become less precise due to the challenging quantification of crosstalk-induced delay. During the routing, the crosstalk effect is typically modeled by predicting coupling capacitance with congestion information. However, the timing estimation tends to be overly pessimistic, as the crosstalk-induced delay depends not only on the coupling capacitance but also on the signal arrival time. This work presents a crosstalk-aware timing estimation method using a two-step machine learning approach. Interconnects that are physically adjacent and overlap in signal timing windows are filtered first. Crosstalk delay is predicted by integrating physical topology and timing features without relying on post-routing results and the parasitic extraction. Experimental results show a match rate of over 99% for identifying crosstalk nets compared to the commercial tool on the OpenCores benchmarks, with prediction results being more accurate than those of other state-of-the-art methods.

eess.SY