Off-chip Decoupling Capacitor Allocation for Chip Package Co-Design

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 macromodel for each block. Compared to the PRIMA-based macromodeling, experiments show that our method (TBS2) is 25X faster and has 3.04X s...

• Type: Conference
• Year: 2007
• Where: DAC
• Authors: Hao Yu, Chunta Chu, Lei He
• Keywords: DAC 2007, Decap Allocation, Decoupling Capacitor Allocation, Design Automation, Legal Decap Positions