22 June 2020 in IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Placement for very-large-scale integrated (VLSI) circuits is one of the most important steps for design closure. We propose a novel GPU-accelerated placement framework DREAMPlace, by casting the analytical placement problem equivalently to training a neural network. Implemented on top of a widely-adopted deep learning toolkit PyTorch, with customized key kernels for wirelength and density computations, DREAMPlace can achieve around 40× speedup in global placement without quality degradation compared to the state-of-the-art multi-threaded placer RePlAce. We believe this work shall open up new directions for revisiting classical EDA problems with advancements in AI hardware and software.
11 April 2025 in Proceedings of the AAAI Conference on Artificial Intelligence
Due to the growing complexity of modern Integrated Circuits (ICs), automating hardware design can prevent a significant amount of human error from the engineering process and result in less errors. Verilog is a popular hardware description language for designing and modeling digital systems; thus, Verilog generation is one of the emerging areas of research to facilitate the design process. In this work, we propose VerilogCoder, a system of multiple Artificial Intelligence (AI) agents for Verilog code generation, to autonomously write Verilog code and fix syntax and functional errors using collaborative Verilog tools (i.e., syntax checker, simulator, and waveform tracer). Firstly, we propose a task planner that utilizes a novel Task and Circuit Relation Graph retrieval method to construct a holistic plan based on module descriptions. To debug and fix functional errors, we develop a novel and efficient abstract syntax tree (AST)-based waveform tracing tool, which is integrated within the autonomous Verilog completion flow. The proposed methodology successfully generates 94.2% syntactically and functionally correct Verilog code, surpassing the state-of-the-art methods by 33.9% on the VerilogEval-Human v2 benchmark.
18 January 2023 in IEEE Journal of Solid-State Circuits
The energy efficiency of deep neural network (DNN) inference can be improved with custom accelerators. DNN inference accelerators often employ specialized hardware techniques to improve energy efficiency, but many of these techniques result in catastrophic accuracy loss on transformer-based DNNs, which have become ubiquitous for natural language processing (NLP) tasks. This article presents a DNN accelerator designed for efficient execution of transformers. The proposed accelerator implements per-vector scaled quantization (VSQ), which employs an independent scale factor for each 64-element vector to enable the use of 4-bit arithmetic with little accuracy loss and low energy overhead. Using a multilevel dataflow to maximize reuse, the 5-nm prototype achieves 95.6 tera-operations per second per Watt (TOPS/W) at 0.46 V on a 4-bit benchmarking layer with VSQ. At a nominal voltage of 0.67 V, the accelerator achieves 1734 inferences/s/W (38.7 TOPS/W) with only 0.7% accuracy loss on BERT-Base and 4714 inferences/s/W (38.6 TOPS/W) with 0.15% accuracy loss on ResNet-50 by using quantization-aware fine-tuning to recover accuracy, demonstrating a practical accelerator design for energy-efficient DNN inference.
4 February 2020 in IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Placement is an important step in modern very-large-scale integrated (VLSI) designs. Detailed placement is a placement refining procedure intensively called throughout the design flow, thus its efficiency has a vital impact on design closure. However, since most detailed placement techniques are inherently greedy and sequential, they are generally difficult to parallelize. In this work, we present a concurrent detailed placement framework, ABCDPlace, exploiting multithreading and GPU acceleration. We propose batch-based concurrent algorithms for widely-adopted sequential detailed placement techniques, such as independent set matching, global swap, and local reordering. Experimental results demonstrate that ABCDPlace can achieve 2×-5× faster runtime than sequential implementations with multi-threaded CPU and over 10× with GPU on ISPD 2005 contest benchmarks without quality degradation. On larger industrial benchmarks, we show more than 16× speedup with GPU over the state-of-the-art sequential detailed placer. ABCDPlace finishes the detailed placement of a 10-million-cell industrial design in one minute.
24 September 2020 in IEEE Micro
Recent advancements in machine learning provide an opportunity to transform chip design workflows. We review recent research applying techniques such as deep convolutional neural networks and graph-based neural networks in the areas of automatic design space exploration, power analysis, VLSI physical design, and analog design. We also present a future vision of an AI-assisted automated chip design workflow to aid designer productivity and automate optimization tasks.