Advertisement

Computation of Flexibility in Sequential Networks

  • Tiziano Villa
  • Nina Yevtushenko
  • Robert K. Brayton
  • Alan Mishchenko
  • Alexandre Petrenko
  • Alberto Sangiovanni-Vincentelli
Chapter

Abstract

There is a long history of resynthesizing an FSM, given its surrounding environment. Much of the work was modeled after results for combinational networks. Thus input sequential don’t cares and output sequential don’t cares were defined in analogy to satisfiability and observability don’t cares. For example, input sequential don’t cares were defined as input sequences that can never happen at a state because of the FSM input environment. An elegant theory was provided by Kim and Newborn for treating the case of a cascade of two FSMs. This is discussed in Sect. 10.1 as well as an extension by Wang and Brayton in Sect. 10.2. These results provide reasonable computational procedures and can be used for resynthesis of an FSM. However, attempts at extending to output sequential don’t cares became overly complicated and were unsuccessful. It was surprising then that Watanabe came up with a computation for the full flexibility for an FSM embedded in an environment, which captures all input and output sequential don’t cares. This was called the “E-machine” and was constructed by a somewhat complicated construction. It became clear later that this construction essentially modeled the subset construction. Now we know that this full flexibility embodied by the E-machine is simply the largest FSM solution obtained by language solving, and a simpler construction is the one given in this book and discussed in this chapter in more detail.

Keywords

Input Sequence State Minimization Dead State Full Flexibility Language Equation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Tiziano Villa
    • 1
  • Nina Yevtushenko
    • 2
  • Robert K. Brayton
    • 3
  • Alan Mishchenko
    • 4
  • Alexandre Petrenko
    • 5
  • Alberto Sangiovanni-Vincentelli
    • 4
  1. 1.Dipartimento D’InformaticaUniversità di VeronaVeronaItaly
  2. 2.Department of EECSTomsk State UniversityTomskRussia
  3. 3.Department of Electrical Engineering and Computer ScienceUniversity of CaliforniaBerkeleyUSA
  4. 4.Department of Electrical Engineering and Computer Science (EECS)University of California, BerkeleyBerkeleyUSA
  5. 5.Computer Research Institute of Montreal (CRIM)MontrealCanada

Personalised recommendations