Publications of the Ptolemy Group
A Preliminary Study of Hierarchical Finite State Machines with Multiple Concurrency Models
Alain Girault, Bilung Lee, and Edward A. Lee
Hierarchical Finite State Machines with Multiple Concurrency Models
Technical Memorandum UCB/ERL M97/57
Electronics Research Laboratory, Berkeley, CA 94720
This paper studies the semantics of hierarchical finite-state machines that
are composed using various concurrency models, particularly dataflow,
discrete-events, and synchronous/reactive modeling. It is argued that
all three combinations are useful, and that therefore the concurrency model
should be selected independently of the decision to use hierarchical FSMs.
In contrast, most formalisms that combine FSMs with concurrency models,
such as Statecharts (and its variants) and Hybrid systems,
tightly integrate the FSM semantics with the concurrency semantics.
An implementation that supports the three combinations studied is described.
Send comments to Edward A. Lee at email@example.com.