SPDIF-AES/EBU digital audio data recovery

摘要

A circuit for decoding an input signal includes a measurement circuit having an input to receive a timing clock signal that is asynchronous with clocking of the input signal, to measure duration of a plurality of pulses received on the input signal in relation to frequency of the timing clock signal and a decode circuit to decode the input signal into digital data. In one embodiment, the circuit may include a servo mechanism for generating the timing clock signal to have a frequency that varies in response to variations in frequency of clocking of data on the input signal. The servo mechanism may include a digitally controlled oscillator and a feedback circuit, to control the digital frequency of the digitally controlled oscillator in response to variation of clocking of data on the input signal. The invention permits use of all digital components for decoding digital audio data encoding using biphase- mark encoded data according to the SPDIF or AES/EBU standards.