Use Clause

Packages must be made visible before they can be used

The USE clause makes packages visible to entities and architectures

 -- use on the binary_new and add_bits3 declarations
USE my_stuff.binary_new, my_stuff.add_bits3;

... ENTITY declaration...
... ARCHITECTURE declaration...

-- use all of the declarations in package my_stuff
USE my_stuff.ALL;

... ENTITY declaration...
... ARCHITECTURE declaration...