Patent ID: 6848009

Claim:
A network interface device for connecting a computer to a network including a port with a plurality of loads for a network communications link and a plurality of functional blocks each one for operating the device according to a different type of network, each type of network being identified a corresponding set of active leads, logic means for detecting if a signal is present on each lead and for determining the type of network corresponding to the present signals, wherein the logic means includes, for each lead, a low-pass filter for obtaining a direct-voltage component of a voltage on the lead, a first comparator for asserting a positive indicator signal when the direct-voltage component is higher than a positive threshold value, a second comparator for asserting a negative indicator signal when the direct-voltage component is lower than a negative threshold value, and means for asserting a null indicator signal when both the positive indicator signal and the negative indicator signal are deasserted, and configuration means including a microprocessor and a memory for storing a program controlling the microprocessor for activating the functional block corresponding to the determined type of network, the microprocessor determining the type of network according to the positive indicator signal, the negative indicator signal, and the null indicator signal corresponding to each lead.