A package includes a first die and a second die. The dies are connected to each other through an interface. At least one of the first and second dies includes a plurality of signal sources, wherein each source has at least one quality of service parameter associated therewith, and a plurality of queues having a different priorities. A signal from a respective one of the signal sources is allocated to one of the plurality of queues in dependence on the at least one quality of service parameter associated with the respective signal source. The interface is configured such that signals from said queues are transported from one of said first and second dies to the other of said first and second dies.