There is provided an avionics system that provides several avionics functions within a single LRU. In one embodiment, the system comprises a software-configurable RF assembly, one or more processor assemblies that are configured to provide multiple TAWS/TCAS/Mode S/ADS-B/ATC functions, interfaces to allow connections to aircraft electronics and data loaders, and multipurpose antennas. In one embodiment, a common processor architecture allows generic avionics processors to be configured to operate a number of TAWS/TCAS/Mode S/ADS-B/ATC functions without the need for multiple LRUs, and software-defined RF functions allow RF circuitry that interfaces to the processors to handle current and future communication needs.