Patent ID: 8908779

Claim:
A serial communications interface, comprising: a differential input/output having a first node and a second node; a plurality of input/output nodes arranged to receive serial interface signals; a transmitter configured to drive a twisted pair cable at the differential input/output; a receiver coupled to the differential input output, the receiver comprising a window comparator; and a serial port controller unit coupled to the serial interface input/output nodes, the transmitter, and the receiver; wherein: the serial port controller unit is configured to provide serial data to the transmitter and receive serial data from the receiver; the transmitter and the twisted pair cable are on opposite sides of the galvanic isolation; the serial port controller, the receiver, and the transmitter are on the same side of the galvanic isolation; and the serial communications interface is: configured to transmit serial data to and receive serial data from a second serial communications interface one data bit at a time, without a clock reference sent with or embedded in the serial data; and configured to be galvanically isolated from the second serial communications interface.