An Exact Jumper-Insertion Algorithm for Antenna Violation Avoidance/Fixing Considering Routing Obstacles

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems (Impact Factor: 1). 05/2007; 26(4):719 - 733. DOI: 10.1109/TCAD.2007.892338
Source: IEEE Xplore


We study in this paper the problem of jumper insertion on general routing (Steiner/spanning) trees with obstacles for antenna avoidance/fixing at the routing and/or postlayout stages. We formulate the jumper insertion for antenna avoidance/fixing as a tree-cutting problem and present the first optimal algorithm for the general tree-cutting problem. We show that the tree-cutting problem exhibits the properties of optimal substructures and greedy choices. With these properties, we present an O((V+D)lgD)-time optimal jumper-insertion algorithm that uses the least number of jumpers to avoid/fix the antenna violations on a Steiner/spanning tree with V vertices and D obstacles. Experimental results show the superior effectiveness and efficiency of our algorithm

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    • "To detect/fix antenna violations, we have to check if the effective conductor connecting to a gate oxide exceeds a threshold L max . Here, L max can be measured in wire-area-to-gate-size ratio, wire area, wirelength, or any model of the strength of antenna effect caused by conductors, same as that in [16] and [17]. To simplify the discussion, we assume that all sinks on a net are connected to a gate terminal, whereas the source is connected to diffusion (those sinks connecting to diffusion can be ignored since they will not cause any antenna violation for current technology). "
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    ABSTRACT: As technology enters the nanometer territory, the antenna effect plays an important role in determining the yield and reliability of a VLSI circuit. Diode and jumper insertions are the most effective techniques to fix the antenna effect. However, due to the increasing design complexity and the limited routing resource, applying diode or jumper insertion alone cannot achieve a high antenna fixing rate. In this paper, we give a polynomial-time antenna violation detection/fixing algorithm by simultaneous diode and jumper insertion with minimum cost, which is based on a minimum-cost network-flow formulation. Experimental results show that our algorithm consistently achieves much higher antenna fixing rates than the state-of-the-art jumper and diode insertion algorithms alone.
    Preview · Article · Jul 2008 · IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
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    ABSTRACT: As VLSI technology advances to smaller technology nodes, the antenna effect has become a critical issue in the yield and reliability of the VLSI circuit, especially for analog ICs. Jumper insertion is an effective technique to fix the antenna effect. Traditional works on antenna fixing are mainly for digital ICs rather than analog ICs. This paper presents heuristic algorithms for jumper insertion during routing for analog ICs, which handles the expansion limitation of different types of nets, such as general nets and matching nets, and reexamines the matching parameters of matching nets after jumper insertion. The experimental results show the effectiveness of our algorithms.
    No preview · Article · Jan 2010
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    ABSTRACT: In this paper, we propose a jumper insertion algorithm under timing and antenna ratio constraints. Differently from the existing works which assume the jumpers to be placed above the highest layer of a routing tree, our work allows the jumpers to be placed on any routing layer. Furthermore, our algorithm is aware of the delay caused by the jumpers. Experimental results show that, by allowing the jumpers to be placed on any layer, the number of vias added by the jumpers can be reduced by 50%. The experiments also show that our timing-aware jumper insertion algorithm is better at satisfying the timing constraints.
    No preview · Conference Paper · Nov 2011
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