Specification and Description Language

What is SDL?

SDL is a formal language developed and standardized by the ITU-T (International Telecommunication Union Telecommunication sector).

Application

Type of systems:

  • real-time
  • interactive
  • distributed
  • heterogenous

Type of information:

  • behavior
  • structure

Level of abstraction:

  • overview to details

It is used for:

  • Formal specification modelling
  • design

SDL structure

A system contains one or more blocks, interconnected with each other and with the boundary of the system by channels. Processes communicate with each other using signals sent over the channels. A process in SDL is an extended finite state machine.

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