System Level Mixed-Signal Modeling in Ptolemy II

Researchers: Jie Liu
Advisor:Edward A. Lee

This work studies and implements continuous time system modeling and simulation in Ptolemy II. In the continuous time model, a system is described in a set of ordinary differential equations (ODE). Differing from the nodal analysis representation in circuit simulation tools like SPICE, the ODEs are represented in Ptolemy II as integrators with feedback loops. This representation is close to the mathematical formulation, thus is suitable for problem level specifications. Various numerical ODE solving methods are studied and implemented, including the Forward Euler, Backward Euler, Trapezoidal Rule, and the Runge-Kutta methods. The formal semantics and the interaction with other models of computation are the central parts of this work. The models of computation of special interests to interact with are the discrete event models, the dataflow models and the finite state machine models. Typical applications are mixed-signal electronic systems, microelectromechanical systems, real-time control systems, and hybrid systems.

Last updated 11/22/98. Send comments to