[eluser]Rick Jolly[/eluser]
I'm not sure that I understand your question.
By "global parameters", do you mean global variables? A parameter is a function argument.
By "the code flows between 3 controllers", do you mean there are 3 browser requests, or do you mean you're using an altered CI that is able to call a controller method from another controller.
If I had to guess, I'd say you are trying to store some user data between 3 page requests. In that case, use the session. You wouldn't want to use the config or any other global persistent storage for user data, since all users would use the same storage and overwrite each other's data.