Ripple is a VLSI placement tool developed by the research team supervised by Prof. Evangeline F.Y. Young in The Chinese University of Hong Kong (CUHK).
Circuits with increasing numbers of cells of multi-row height have brought challenges to traditional placers on efficiency and effectiveness.
Besides providing an overlap-free solution close to the global placement (GP) solution, constraints on power and ground (P/G) alignments, fence region, and routability (e.g., edge spacing, pin short/inaccessible) should be considered.
To tackle the challenges, we design and implement several efficient and effective data structures and algorithms under a holistic framework:
- a legalization method for mixed-cell-height circuits by a window-based cell insertion technique,
- an iterative network-flow-based maximum displacement optimizations,
- a dual-network-flow-based fixed-row-and-order optimization,
- ...
More details are in the following papers:
- Xu He, Tao Huang, Linfu Xiao, Haitong Tian, Guxin Cui, Evangeline F.Y. Young, "Ripple: An Effective Routability-Driven Placer by Iterative Cell Movement", IEEE/ACM International Conference on Computer-Aided Design (ICCAD), San Jose, CA, USA, Nov. 7 - Nov. 10, 2011.
- Xu He, Tao Huang, Wing-Kai Chow, Jian Kuang, Ka-Chun Lam, Wenzan Cai, Evangeline F.Y. Young, "Ripple 2.0: High Quality Routability-Driven Placement via Global Router Integration", ACM/IEEE Design Automation Conference (DAC), Austin, TX, USA, May 29 - June 7, 2013.
- Wing-Kai Chow, Chak-Wa Pui, Evangeline F.Y. Young, "Legalization Algorithm for Multiple-Row Height Standard Cell Design", ACM/EDAC/IEEE Design Automation Conference (DAC), Austin, TX, USA, June 5 - June 9, 2016.
- Haocheng Li, Wing-Kai Chow, Gengjie Chen, Evangeline F.Y. Young, Bei Yu, "Routability-Driven and Fence-Aware Legalization for Mixed-Cell-Height Circuits", ACM/EDAC/IEEE Design Automation Conference (DAC), San Francisco, CA, USA, June 24 - June 29, 2018.
- Haocheng Li, Wing-Kai Chow, Gengjie Chen, Bei Yu, Evangeline F.Y. Young, "Pin-Accessible Legalization for Mixed-Cell-Height Circuits", IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems (TCAD), 2021.
Step 1: Download the source codes. For example,
$ git clone https://github.com/cuhk-eda/rippleStep 2: Go to the project root and build by
$ cd ripple/src
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License Agreement for Ripple
Copyright (c) 2021, The Chinese University of Hong Kong All rights reserved.
CU-SD LICENSE (adapted from the original BSD license) Redistribution of the any code, with or without modification, are permitted provided that the conditions below are met.
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