An IO controller device and method for controlling data flow, the method including determining a desired configuration for the IO controller, reprogramming the IO controller to allow for processing of one or more descriptor lists, modifying the configuration of the IO controller to reflect the addition or deletion of one or more virtual controllers, re-enumerating the IO controller, and processing a descriptor list for each of the IO controller and the one or more virtual controllers. The integrated circuit device for use as an IO controller includes a system bus interface, a programmable list processor and a port router. The integrated circuit device is adapted for reconfiguration to add or delete one or more virtual controllers. The virtual controllers provide substantially the full bandwidth supported by the integrated circuit device. The IO controller device and apparatus may be applied to personal computer systems, information appliances, set-top boxes, cable modems, game consoles, smart appliances, handheld computers, palm-sized computers, embedded control systems, workstations, servers and the like.