2C: Analog CAD Techniques: From Analysis to Verification


2C-1
Title Thermal-driven Symmetry Constraint for Analog Layout with CBL Representation
Author *Jiayi Liu, Sheqin Dong, Yunchun Ma, Di Long, Xianlong Hong (EDA lab, DCST, Tsinghua University, China)
Abstract Thermal constraint is very important for analog devices in the context of SOI. Hot-spot effect would cause error or even failure on the performance of analog devices. And the temperature gradient would lead to mismatch on symmetrical devices. In order to handle these problems, this paper introduces an accurate thermal model into the placement process. Based on the geometric symmetry which is achieved with CBL for the first time, the thermal model helps to find the thermal-optimal placement. And the experimental results show this method is promising.
Slides (pdf file) 2C-1

2C-2
Title A Graph Reduction Approach to Symbolic Circuit Analysis
Author *Guoyong Shi, Weiwei Chen (Shanghai Jiao Tong University, China), C.-J. Richard Shi (University of Washington, United States)
Abstract A new graph reduction approach to symbolic circuit analysis is developed in this paper. A Binary Decision Diagram (BDD) mechanism is formulated, together with a specially designed graph reduction process and a recursive sign determination algorithm. This combination of techniques is used to develop a core analysis engine of a symbolic analog circuit simulator that has the potential for analyzing large analog circuits in the frequency domain. Partial experimental results are reported.
Slides (pdf file) No Show

2C-3
Title Robust Analog Circuit Sizing Using Ellipsoid Method and Affine Arithmetic
Author Xuexin Liu, *Wai-Shing Luk, Yu Song, Xuan Zeng (ASIC & System State-Key Lab, Fudan University, China)
Abstract Analog circuit sizing under process/parameter variations is formulated as a mini-max geometric programming problem. To tackle such problem, we present a new method that combines the ellipsoid method and affine arithmetic. Affine Arithmetic is not only used for keeping tracks of variations and correlations, but also helps to determine the sub-gradient at each iteration of the ellipsoid method. An example of designing a CMOS op-amp is given to demonstrate the effectiveness of our method. Finally numerical results are verified by SPICE’s simulation.
Slides (pdf file) 2C-3

2C-4
Title WCOMP: Waveform Comparison Tool for Mixed-signal Validation Regression in Memory Design
Author *Peng Zhang, Wai-Shing Luk, Yu Song, Jiarong Tong, Pushan Tang, Xuan Zeng (Fudan University, China)
Abstract The increasing effort on full-chip validation constrains design cost and time-to-market. A waveform comparison tool named WCOMP is presented to automate mixed-signal validation regression in memory design. Unlike digital waveform comparison tools, WCOMP compares mixed-signal waveforms for functional match instead of graphical match, which tally with the requirements of full-chip validation regression. Simulations with different regression runs, process parameters, voltages and temperatures can be functionally compared. The methods are proved to be effective in Intel Flash memory design.
Slides (pdf file) 2C-4

2C-5
Title Structured Placement with Topological Regularity Evaluation
Author *Shigetoshi Nakatake (University of Kitakyushu, Japan)
Abstract This paper introduces a new concept of floorplanning, called structured placement. Regularity is the key criterion so that the placement can make progress beyond constraint-driven approaches. We propose a linear time extration of topological regularity like arrays and rows from a sequence-pair. Besides, we provide a new simulated annealing (SA) framework, called dual SA, which optimizes the regularity as an objective function balancing the size of regular structures against the area efficiency.
Slides (pdf file) 2C-5
Last Updated on: January 26, 2007