One or more methods and systems of sharing an external memory between functional modules of an integrated circuit chip are presented. The invention provides a system and method of reducing the amount of off-chip memory utilized by one or more integrated circuit chips. In one embodiment, a method for sharing an off-chip memory among one or more on-chip functional modules comprises arbitrating the communication of data between one or more on-chip functional modules and the off-chip memory. In one embodiment, the arbitration is facilitated by using an internal data bus that is controlled by a bus arbiter control unit. In one embodiment, a system for sharing an off-chip memory between functional modules of an integrated circuit comprises a security processing module, a media access controller module, a data interface, and a data bus.