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Austin Rovinski

Publications and source records attributed to Austin Rovinski.

6 recordsLinked to original sources

Routing Dense Layouts with History-Aware Offline Reinforcement Learning using LSTM

Detailed routing remains a dominant runtime bottleneck in physical design due to increasing complexity of design rules. Modern routers can struggle to resolve persistent violations under dense operating conditions. While recent work leverages reinforcement learning (RL) to dynamically select costs for each routing iteration, we find that this technique struggles with high-density designs where routing solutions are significantly harder. To address this, we present a history-aware offline RL policy which predicts iterative cost weights in these dense regimes to improve convergence across placement densities by utilizing readily available features from the router. Our policy uses conservative Q-learning similarly to prior work; however, our key insight is that addition of a lightweight LSTM architecture and additional features can retain sequence context and improve routing convergence across multiple densities and route guide qualities. Our policy can be integrated into any cost-based router with minimal pipeline changes, as it does not interfere with the core search algorithm. We evaluate our policy on held-out density and adjustment settings, including difficult operating points induced by dense placement and low guide quality. Our policy reduces design rule violations (DRVs) by an average of 92% over the top public baseline while simultaneously reducing runtime by 10%.

cs.AR

Revisiting Hardware Priority Queue Architectures

Priority queues - data structures that serve elements based on priority rather than insertion order - are fundamental in a wide range of applications, including operating systems, graph algorithms, and data compression. Software implementations, typically based on binary heaps with O(log N) complexity, are sufficient for many scenarios; however they can become performance bottlenecks in latency-sensitive domains such as networking and robotics. Hardware-based priority queues exploit parallelism to significantly reduce operation latency, delivering critical performance improvements in latency-sensitive applications. Despite the breadth of prior work on hardware priority queues, two major challenges remain. First, many foundational architectures were proposed and studied years ago, calling into question their relevance given modern hardware advancements. Second, comprehensive comparisons across different architectures are lacking, making it difficult to evaluate trade-offs in performance, resource utilization, and scalability. This paper addresses both gaps by implementing and evaluating several representative hardware priority queue architectures on modern FPGA platforms and providing a quantitative analysis to guide future design choices. All implementations, tests, and analyses are available through our open-source library at https://github.com/realise-lab/hwpq.

cs.AR

ORRAM: An OpenROAD-Integrated RAM Generator Using Standard Cells

Memory inference remains a significant challenge in turnkey ASIC design flows. Inferring flip-flops from RTL can create thousands of densely interconnected instances which dramatically slow down design flows and impede performance. Memory compilers address this issue, although they are third-party tools which are often PDK-specific and may require specialized cells not in the base PDK. To address these shortcomings, we present ORRAM, a standard-cell-based memory generator built as a native module within OpenROAD. Given a standard cell library, ORRAM produces a fully placed and routed RAM block requiring no custom bitcells or external tooling, with timing verification via OpenSTA rather than SPICE simulation. ORRAM supports arbitrary word sizes, word counts, mask granularities, multi-port read configurations, column muxing, latch-based storage, and automatic PDK-agnostic cell selection, making it compatible with most standard cell libraries including sky130hd and NanGate45. Evaluated on SkyWater 130nm, ORRAM matches the bit density of historical DFFRAM results while offering a significantly expanded feature set. The source code is available as part of the OpenROAD project.

cs.AR

CLIPGen: A Chiplet Link IP Modeling and Generation Framework for 2.5D Architecture Exploration

Advanced 2.5D Systems-in-Package (SiPs) compose a growing portion of high-performance systems. While the packaging and interconnect choices play a large role in the overall system design, system architects still lack a suitable framework for early design space exploration which takes these choices into account. Current interconnect models fall mostly into the categories of 1) detailed models which are generally inflexible and require deep packaging expertise, or 2) high-level models which don't provide enough information to make accurate architectural design decisions. In this work, we present an automated chiplet IP generation framework which provides power, performance, and area estimates for various 2.5D packaging and communication configurations. The IP generator produces standard collaterals required for high-level simulation/estimation, RTL simulation, and place-and-route-level implementation (Verilog, Liberty, LEF, and datasheet). Using our framework, architects can co-optimize the package and chiplet architecture through rapid power, performance, and area estimates of various packaging strategies. As a case study, we examine generated UCIe interfaces across several packaging options.

cs.AR

Accelerating Detailed Routing Convergence through Offline Reinforcement Learning

Detailed routing remains one of the most complex and time-consuming steps in modern physical design due to the challenges posed by shrinking feature sizes and stricter design rules. Prior detailed routers achieve state-of-the-art results by leveraging iterative pathfinding algorithms to route each net. However, runtimes are a major issue in detailed routers, as converging to a solution with zero design rule violations (DRVs) can be prohibitively expensive. In this paper, we propose leveraging reinforcement learning (RL) to enable rapid convergence in detailed routing by learning from previous designs. We make the key observation that prior detailed routers statically schedule the cost weights used in their routing algorithms, meaning they do not change in response to the design or technology. By training a conservative Q-learning (CQL) model to dynamically select the routing cost weights which minimize the number of algorithm iterations, we find that our work completes the ISPD19 benchmarks with 1.56x average and up to 3.01x faster runtime than the baseline router while maintaining or improving the DRV count in all cases. We also find that this learning shows signs of generalization across technologies, meaning that learning designs in one technology can translate to improved outcomes in other technologies.

cs.AR

EDA Corpus: A Large Language Model Dataset for Enhanced Interaction with OpenROAD

Large language models (LLMs) serve as powerful tools for design, providing capabilities for both task automation and design assistance. Recent advancements have shown tremendous potential for facilitating LLM integration into the chip design process; however, many of these works rely on data that are not publicly available and/or not permissively licensed for use in LLM training and distribution. In this paper, we present a solution aimed at bridging this gap by introducing an open-source dataset tailored for OpenROAD, a widely adopted open-source EDA toolchain. The dataset features over 1000 data points and is structured in two formats: (i) a pairwise set comprised of question prompts with prose answers, and (ii) a pairwise set comprised of code prompts and their corresponding OpenROAD scripts. By providing this dataset, we aim to facilitate LLM-focused research within the EDA domain. The dataset is available at https://github.com/OpenROAD-Assistant/EDA-Corpus.

cs.CL