The Control Module performs its job asynchronously from the Analysis Module. It handles communication with the supervisory interface and with the hardware in the Analysis Module to which it is attached. To the supervisor interface, the Control Module must report traffic violations detected and read from the Analysis Modules and get information about new valid data paths that have been created in the network. When the Control Module receives data about a new valid path, it must be able to distinguish through which Analysis Module the path passes and must update the valid path information within this module.
A Motorola 68PM302 Integrated Multiprotocol Processor is an ideal candidate because of its current availability at reasonable cost and its capability to provide a broad range of built-in features that closely match the needs of this application. It provides sufficient I/O to be able to perform all the necessary read and write operations to and from the Analysis Module hardware. It offers the interrupt circuitry necessary for the Analysis Module to alert the Control Module of a traffic violation. Finally, it provides a high-speed serial interface, which could be used in conjunction with a DS1 compliant transceiver in order to communicate with the Control Module's supervisory interface.