Patent ID: 7890284

Claim:
An identification system for recognizing a device as one of a plurality of different types of devices connected to at least one terminal of an information handling system comprising: an excitation circuit for supplying a test signal to a device in a test mode; a response analyzer circuit responsive to the test signal being applied to said device in the test mode for measuring an electrical characteristic of said device; an identification circuit responsive to the measured electrical characteristic of said device for matching a stored representation of said electrical characteristic of said device with representations of the electrical characteristics of said plurality of devices for recognizing said device connected to the terminal as one of said plurality of different devices; and a reconfiguration circuit connected to said terminal and responsive to the identification of said device for reconfiguring circuitry connecting the identified device to the information handling system to adapt to the identified said device by selectively operating a switching circuit; an event detector for detecting the presence and absence of a device connected to a said terminal, the event detector including: a resistor ladder network connected between a node and the terminals for conditioning the voltage at the node to vary depending on whether devices are connected to one or more of the terminals; and a comparison circuit for detecting whether the voltage at the node has changed.