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The 16th Asia and South Pacific Design Automation Conference

Session 1A  Analog, Mixed-Signal & RF Verification, Abstraction and Analysis
Time: 10:20 - 12:20 Wednesday, January 26, 2011
Location: Room 411+412
Chairs: Eric Keiter (Sandia National Labs, U.S.A.), Chin-Fong Chiu (National Chip Implementation Center, Taiwan)

1A-1 (Time: 10:20 - 10:50)
TitleAnalog Circuit Verification by Statistical Model Checking
Author*Ying-Chih Wang, Anvesh Komuravelli, Paolo Zuliani, Edmund M. Clarke (Carnegie Mellon University, U.S.A.)
Pagepp. 1 - 6
KeywordAnalog Circuits, Verification, Statistical Model Checking
AbstractWe show how statistical Model Checking can be used for verifying properties of analog circuits. As integrated circuit technologies scale down constantly, manufacturing variations in devices make analog designs behave like stochastic systems. In this paper, we use statistical model checking, an efficient verification technique for stochastic systems, for verifying properties of analog circuits in both the temporal and the frequency domain. In particular, randomly sampled traces are sequentially generated by SPICE and model checked to determine whether they satisfy a given specification, until the desired statistical strength is achieved.
Slides

1A-2 (Time: 10:50 - 11:20)
TitleFSM Model Abstraction for Analog/Mixed-Signal Circuits by Learning from I/O Trajectories
Author*Chenjie Gu, Jaijeet Roychowdhury (University of California, Berkeley, U.S.A.)
Pagepp. 7 - 12
Keywordmodel abstraction, finite state machine, analog/mixed-signal
AbstractAbstraction of circuits is desirable for faster simulation and high-level system verification. In this paper, we present an algorithm that derives a Mealy machine from differential equations of a circuit by learning input-output trajectories. The key idea is adapted from Angluin's DFA (deterministic finite automata) learning algorithm that learns a DFA from another DFA. Several key components of Angluin's algorithm are modified so that it fits in our problem setting, and the modified algorithm also provides a reasonable partitioning of the continuous state space as a by-product. We validate our algorithm on a latch circuit and an integrator circuit, and demonstrate that the resulting FSMs inherit important behaviors of original circuits.

1A-3 (Time: 11:20 - 11:50)
TitleA Structured Parallel Periodic Arnoldi Shooting Algorithm for RF-PSS Analysis based on GPU Platforms
AuthorXue-Xin Liu (University of California, Riverside, U.S.A.), Hao Yu (Nanyang Technological University, Singapore), Jacob Relles, *Sheldon X.-D. Tan (University of California, Riverside, U.S.A.)
Pagepp. 13 - 18
Keywordshooting-Newton, periodic steady state analysis, GPU, RF, Krylov
AbstractThe recent multi/many-core CPUs or GPUs have provided an ideal parallel computing platform to accelerate the time-consuming analysis of radio-frequency/millimeter-wave (RF/ MM) integrated circuit (IC). This paper develops a structured shooting algorithm that can fully take advantage of parallelism in periodic steady state (PSS) analysis. Utilizing periodic structure of the state matrix of RF/ MM-IC simulation, a cyclic-block-structured shooting-Newton method has been parallelized and mapped onto recent GPU platforms. We first present the formulation of the parallel cyclic-block-structured shooting-Newton algorithm, called {\em periodic Arnoldi shooting} method. Then we will present its parallel implementation details on GPU. Results from several industrial examples show that the structured parallel shooting-Newton method on Tesla's GPU can lead to speedups of more than 20$\times$ compared to the state-of-the-art implicit GMRES methods under the same accuracy on the CPU.

1A-4 (Time: 11:50 - 12:20)
TitleHierarchical Exact Symbolic Analysis of Large Analog Integrated Circuits By Symbolic Stamps
Author*Hui Xu, Guoyong Shi, Xiaopeng Li (Shanghai Jiao Tong University, China)
Pagepp. 19 - 24
Keywordanalog integrated circuits, binary decision diagram, determinant expansion, graph reduction, symbolic analysis
AbstractLinearized small-signal transistor models share the common circuit structure but may take different parameter values in the ac analysis of an analog circuit simulator. This property can be utilized in symbolic circuit analysis. This paper proposes to use a symbolic stamp for all device models in the same circuit for hierarchical symbolic analysis. Two levels of binary decision diagrams (BDDs) are used for maximum data sharing, one for the symbolic device stamp and the other for modified nodal analysis. The symbolic transadmittances of the device stamp share one BDD for storage saving. The modified nodal analysis (MNA) matrix formulated using symbolic stamp is of greatly lower dimension, hence its solving complexity by using a determinant decision diagram (DDD) is greatly reduced. A circuit simulator is implemented based on the proposed scheme. It is able to analyze an op-amp circuit containing 44 MOS transistors \emph{exactly} for the first time.
Slides