An apparatus and method for a processor-memory unit for use in system-in-package (SiP) and system-in-package (SiP) integrated circuit devices. The apparatus includes a processing module, a memory module and a programmable system module. The programmable system module is configured to function as an interface between the memory module and the processing module, or as an interface between the memory module and a testing device. The invention facilitates integration and testing of processor-memory units including functional components having different communication protocols.