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.