Methods, systems, processing units, and signals for transferring data of various data types across a common data path interface are disclosed. A representative method for transferring data between a master processing unit and at least a first slave processing unit via a common data path interface, the master processing unit and the at least first slave processing unit are configured to process a plurality of non-Asynchronous Transfer Mode (ATM) data types, includes: receiving the data; generating an ATM cell in an ATM cell format determined from a plurality of ATM cell formats; transferring the ATM cell across the common data path interface to an appropriate processing unit; and processing the ATM cell upon receiving it from the common data path interface.