Relationship between automotive manufacturer and supplier

  • manufacturers define system requirements and environment.
  • suppliers are responsible for system development (thermo control, ABS...)
  • good cooperation between manufacturer and suppliers results in short and efficient development cycles.


  • System design requires models for adaptation and simulation of system + environment
  • Seamless design flow requires modeling language usable on all simulators to save cost for model development and tool purchase

Goals of Working Group VHDL-AMS

Tasks of Working Group VHDL-AMS

  • Development of model examples
    • implementation of models in VHDL-AMS
    • exchange of models including test bench and documentation
    • exchange of experiences concerning simulation results of different tools (stability, computation time etc.)
  • Evaluation of tools for converting SPICE, MAST, … to VHDL-AMS
  • Definition of a subset of VHDL-AMS for Real-time applications (VHDL-AMS-RT) to model plants tool independently
  • Cooperation with tool developer (Avant!, ETAS, Mathworks, Mentor Graphics, …)
  • Building of an MSR library and package

VHDL-AMS Modeling Concepts

  • Structural decomposition
  • Communication
    • signal flow
    • power bond
  • Analog
    • Differential algebraic equations
    • transfer functions
  • Event driven (time discrete)
    • event driven communicating parallel processes
  • Analog - discrete (event driven) interaction
    • threshold crossing
    • break

VHDL-AMS Subset for Real-Time (VHDL-AMS-RT)

Example of Real-Time Subset (VHDL-AMS-RT)

Advantages of unified modeling with VHDL-AMS
  • Readable documentation of discontinuous behavior
  • Facilitates model exchange
  • Facilitates model reuse
  • Facilitates tool substitution
  • Reduces training cost
  • Gives chance for niche products with solutions for partial problems
  • Competition will strengthen capabilities of the tools and will (hopefully) reduce tool cost
  • Modeling concepts have proper semantics