You are probably thinking of Pidgins and Creoles[0], two very well studied linguistic categories that come about when two or more groups with no shared language come together (Pidgin) and then their children learn the Pidgin as a first language (morphing it into a Creole). AAVE is grammatically and functionally distinct from either a Pidgin or a Creole.

[0]https://en.wikipedia.org/wiki/Creole_language