[SDL Forum Society - Logo] Tutorial on SDL-88
Belina, Hogrefe (edits Reed)

2. Basic system structure

Back Up Next

Since systems that are subject to specification are usually quite complex, any specification language should have some structuring concepts. In basic SDL-88 a system definition is structured into block definitions and process definitions. Figure 4 shows an example. Additional structural concepts are introduced in the section about "Additional structural concepts".

wpe1.gif (5554 bytes)

Figure 4: Structuring of a system definition into block definitions and process definitions

Note that the structuring concepts can be used for two different purposes:

  1. to structure the definition of the system behaviour (regarding the system as a black box), or
  2. to describe the internal structure of the system as a result of a design activity.

For example, the block concept, when used for the first purpose, only represents a unit of definition, and not part of the system. When used for the second purpose, each block usually represents a part in an implementation of the system. In the following, no distinction will be made between he two cases.

2.1 System structure
2.2 Block structure

Back Up Next

Contact the webmaster with questions or comments about this web site.
Copyright 1997-May, 2013 SDL Forum Society