Abstract: A plug-in device detection module includes a measurement signal generator for generating a measurement signal. A port coupler couples the measurement signal to a selected plug-in receptor of a plurality of plug-in receptors, generates an input/output signal and generates a port signal in response to the measurement signal. A reference signal generator generates a reference signal based on the input/output signal, the reference signal having a plurality of reference signal values. A detection module detects a plug-in device type of a plug-in device coupled to the selected plug-in receptor, based on the reference signal and the port signal.

Abstract: A method and apparatus for recovering data by a digital audio interface begins by receiving a stream of biphase encoded data. The processing continues by determining whether a next transition of a frame of the plurality of frames occurs during a first, second, or third time window after a preceding transition of the frame. When the next transition occurs during the second predetermined time, the digital audio interface synchronizes to a data rate of the stream of biphase encoded data based on the next transition and the preceding transition. If, the next transition occurs during the first or third predetermined windows, the digital audio interface synchronizes to a data rate of the stream of biphase encoded data based on the preceding transition edge and a subsequent transition. When the transition occurs during the third time window, the biphase encoding is violated, which indicates that a preamble is being received.