Slide 13 of 43
As indicated in the previous slide, configuration declarations provide a mechanism for replacing design objects in structural descriptions easily.
Similarly, they allow for structural descriptions to be developed before the entity/architecture building blocks have been finalized. This is particularly useful in a large system which may have been partitioned among several designers.
In addition, idealized components can be made to accommodate actual entity/architecture design object interface requirements in the configuration declaration. This may, for example, be used to tie generics and/or unused signals fixed values (e.g. enable signals to a constant ON value).