An audio codec for converting digital audio signals to analogue audio in smartphones

摘要

The present invention provides an audio codec for converting digital audio signals to analogue audio signals, the audio codec comprising at least two digital audio bus interfaces for coupling to respective digital audio buses, the first bus interface being arranged to operate according to an audio codec protocol, a plurality of circuit elements including a digital to analogue converter and switching means controllable to couple a selected one(s) of the circuit elements between the first and second digital audio bus interfaces, the audio codec being operable to receive two digital audio signals which are not left and right signals corresponding to each other, via the second digital audio bus interface and transmit them via the first bus interface using two respective channels of the audio codec protocol a digital-only signal path between the two digital audio bus interfaces, such that no analogue processing of the audio signals occurs in the digital-only signal path. In the case that the audio codec has three bus interfaces, the two signals sent over the audio codec interface do not need to be received over the same bus interface and the audio codec can be used to receive two signals on separate channels. One independent claim requires that the two signals are both received over a second interface while the two further independent claims require that the two signals pass over respective ones of a second and third interface. The application is to smartphones.