共查询到19条相似文献,搜索用时 171 毫秒
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本文提出了一种在通道内将P/G网与信号网的实体布线一体化考虑的优化布线策略,目的是在保证100%布通的前提下,完成P/G网的平面化实体嵌入和信号网的实体布线,并使P/G走线对信号网走线的影响尽可能小。算法以提高布线区利用率、减小通道高度和减少通孔数为目标,实现总体性能的优化。系统实现的结果表明,本文算法所采用的策略是可行的、有效的。 相似文献
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由于不断增长的芯片引脚数量、极高的引脚密度和独特的物理限制,印刷电路板(Printed Circuit Board,PCB)的手动布线已成为一项耗时的任务。近年来,高效率的自动化布线技术得到了广泛的研究。区域布线是PCB设计的一个重要组成部分。针对基于静态网格区域布线的方案,布线拥塞、布通率低等问题,本文提出了一套基于动态网格的135度区域布线算法,主要包括以下技术:(1)对当前布线采用实时扩展动态网格;(2)135度布线角度节点调整算法;(3)基于拥塞控制的改进A*算法;(4)有效的拆线重布机制。实验结果表明,该算法对于所有工业界布线测试用例布通率都达到100%,并且运行时间方面优于工业布线器Free Routing和Allegro。 相似文献
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本文对现有的总体布线方法及宏单元阵列总体布线问题进行了详细分析,提出了一种基于带权动态调整思想的适合于宏单元阵列一层半和双层版图模式的总体布线算法,其目标是合理地利用已确定的布线区域,使各线网均匀地分布在芯片上,获得尽可能高的布通率。 相似文献
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Due to the rapid development of space communication, satellite networks will be confronted with more complex space environment in future, which poses the important demand on the design of the survivable and efficient routing protocols. Among satellite networks, two-layered Low Earth Orbit (LEO)/Medium Earth Orbit (MEO) satellite networks (LMSNs) have become an attractive architecture for their better communication service than single-layered satellite networks. To determine the topological dynamics of LMSN, the satellite group and group manager (SGGM) method is a prevalent strategy. However, it can not precisely capture the topological dynamics of the LEO layer, which may result in the unreliability of data transmission. Besides, most existing routing protocols based on the SGGM method will collapse once any top satellite fails. To overcome both limitations, this paper proposes a new topology control strategy for LMSNs. The proposed strategy determines the snapshot in terms of the topological change of the LEO layer, which ensures the topological consistency of routing calculation. Moreover, a new survivable routing protocol (SRP) is presented for LMSNs by combining both centralized and distributed routing strategies. The SRP can provide strong survivability under the LEO or MEO satellite failure. Besides, it can also achieve the minimum delay routing provided the MEO layer can effectively work. The performance of SRP is also evaluated by simulation and analysis. 相似文献
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一种新的基于知识的四边通道布线算法 总被引:1,自引:0,他引:1
本文提出了一种新的基于知识的双层四边通道布线算法,该算法对四边通道的布线是通过以下四步完成的。首先,对四边通道的四个角布线,其次,对关键线网优先布线,接下来,利用线网间相互制约关系进行同步增长布线;最后,对仍然没有完成连接的线网,用李氏算法布线。由于使用了启发式规则,使得该算法具有较高的布通率和布线效率。 相似文献
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一种新的基于单元扩大的拥挤度驱动的布局算法 总被引:6,自引:6,他引:0
描述了一种新的基于单元扩大的拥挤度驱动的布局算法 .这个方法用概率估计模型和星型模型来评价线网的走线 .使用全局优化和划分交替的算法来进行总体布局 .提出了单元的虚拟面积的概念 ,单元的虚拟面积不仅体现了单元的面积 ,而且指出了对布线资源的需求 .单元的虚拟面积可以由单元的扩大策略来得到 .把单元的虚拟面积用到划分过程中 ,从而减小拥挤度 .并且使用了单元移动的策略来进一步减小走线的拥挤 .用来自美国公司的一些例子测试了这个算法 ,结果显示布局的结果在可布性方面有了很大的提高 相似文献
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Yici Cai Author Vitae Jin Shi Author Vitae Author Vitae Xianlong Hong Author Vitae Author Vitae 《Integration, the VLSI Journal》2008,41(1):153-160
This paper proposes a hierarchical relaxed approach to analyze large scale on-chip power/ground (P/G) grids with C4 packages efficiently. Different from the existing hierarchical approach where macro models and time-consuming matrix density reduction technique are used, this novel approach uses an iterative relaxation procedure to explicitly exploit the character of boundary nodes caused by C4 bumps, which can lead to more speedup without losing any accuracy. Also, an efficient partition strategy is generated to help the new algorithm to achieve higher performance on C4 based P/G grid. Experimental results demonstrate that the new algorithm is as accurate as the existing hierarchical method while it delivers more speedup over it for C4 based P/G grid. 相似文献
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本文在分析线网之间关系的基础上提出了自由分层条件下的通道区布线模型:同层限制图Gs,相交图Gi,基于这一模型,分析了二层布线条件下对线网分层和布线序的基本限制,导出了分层的基本原则,在此基础上,分析了线网可Overlap的性质和条件,从总体分析的思想出发,提出了直接以完成布线通道区所需面积最小化为目标的分层布线算法,实验结果表明,通道区布线面积和通孔的致目比基于横竖分层的布线算法有较大减少,对于Deutsch′s diffjcult example,该算法获得18个track解。 相似文献
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Recently more and more research interest focuses on the energy efficient routing in mobile ad hoc networks and many related routing algorithms are reported. In this paper, a new optimized priority based energy efficient routing algorithm is presented and priority is added to the existing routing algorithm according to the residual energy proportion of the nodes. Lower residual energy means lower priority and the nodes with lower priority are less likely to forward packets to other nodes. The algorithm needs no global information of the networks and only a little modification is needed to the existing algorithm, so it is practical to be implemented. The algorithm can improve the performance of routing discovery, routing maintenance and cache management at the same time. Some optimization strategy is taken to reduce the network overhead and the lifetime of the network is much longer and the network with our algorithm can transfer much more effective data. Simulation with NS-2 is done and satisfying results are obtained with this algorithm. The results show that the algorithm is efficient. 相似文献