Research in Physical Design of VLSI Circuits

首席研究员将研究超大规模集成电路设计模型， 方法论。 在建模的方向，他会找到模型， 准确描述物理约束和要求 设计过程 在方法论方面，他将应用 算法技术来设计自动化问题， 数学的和形式化的，这样它们就可以被评估和分析， 在实验之前。 刘教授将集中在这些 主题：（1）二维布局问题的方法;（2） 将布图规划技术扩展到非切片模块和L- 形状的结构;和（3）调查的算法，可能 从并行计算中获益，例如同时全局路由。 这项研究解决了需要快速产生布局非常和 超大规模集成（VLSI/ULSI）电路， 有效地 这是一种需要，已成为至关重要的， 这种装置变得更加复杂 竞争择优的科学化 在VLSI/ULSI中有许多解决问题的方法 设计;然而，它们遭受两个问题之一。 要么 设计方法是启发式的，可能会意外失败，因为分析 方法没有得到很好的开发;或者正式的算法，这是很好的 要理解，当涉及非常大的电路时，需要花费太多的时间。 基本的需要是更现实和复杂的模型， 计算和新的分析方法，将导致有效的 VLSI/ULSI设计方法。 刘教授提出解决研究 超大规模集成电路理论中的问题（如布局规划、布线和并行 设计技术），并将解决方案以软件形式进一步 研究他们。 首席研究员在过去几年里， 他把注意力转向了超大规模集成电路，在这方面他做出了重要贡献 在理论上，同时考虑实际问题。

The principal investigator will do research on VLSI design models and methodologies. In the direction of modeling, he will find models that describe accurately the constraints and requirements of the physical design process. In the direction of methodologies, he will apply algorithmic techniques to design automation problems, which are mathematical and formal, so that they can be evaluated and analyzed prior to experimentation. Professor Liu will concentrate on these topics: (1) two-dimensional approaches to the layout problem; (2) the extension of floorplanning techniques to non-slicing modules and L- shaped structures; and (3) the investigation of algorithms that might profit from parallel computation, e.g. simultaneous global routing. This research addresses the need to produce rapidly layouts of very and ultra large-scale integrated (VLSI/ULSI) circuits which operate efficiently. It is a need that has become of paramount importance as such devices become more complex and the industry increasingly competitive. There are many approaches to problems in VLSI/ULSI design; however they suffer from one of two problems. Either the design methods are heuristic and can fail unexpectedly because analysis methods are not well developed; or formal algorithms, which are well understood, take too much time when very large circuits are involved. The basic need is for more realistic and sophisticated models of computation and new analysis methods that will lead to efficient VLSI/ULSI design methods. Professor Liu proposes to solve research problems in VLSI theory (e.g. floorplanning, routing and parallel design techniques) and put the solutions in software form to further study them. The principal investigator has, in the past several years, turned his attention to VLSI, where he has made important contributions to theory while keeping practical problems in mind.