Off-chip decoupling capacitor allocation for chip package co-design
Chu, Chunta Lei He
Date of Issue2007
Design Automation Conference (44th : 2007 : San Diego, USA)
School of Electrical and Electronic Engineering
Off-chip decoupling capacitor (decap) allocation is a demanding task during package and chip codesign. Existing approaches can not handle large numbers of I/O counts and large numbers of legal decap positions. In this paper, we propose a fast decoupling capacitor allocation method. By applying a spectral clustering, a small amount of principal I/Os can be found. Accordingly, the large power supply network is partitioned into several blocks each with only one principal I/O. This enables a localized macromodeling for each block by a triangular-structured reduction. In addition, to systemically consider a large legal position map in a manageable fashion, the map of legal positions is decomposed into multiple rings, which are further parameterized in each block. The decaps are then allocated according to the sensitivity obtained from the parameterized macro-model for each block. Compared to the PRIMA-based macromodeling, experiments show that our method (TBS2) is 25X faster and has 3.04X smaller error. Moreover, our decap allocation reduces the optimization time by 97X, and reduces decap cost by up to 16% to meet the same power-integrty target.
Design automation conference (DAC)
© ACM, 2007. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in Proceeding DAC '07, Proceedings of the 44th annual Design Automation Conference, http://doi.acm.org/10.1145/1278480.1278635