A peripheral device for communication with an audio system, comprising:
- one or more processing modules for performing operations with respect to audio data;
- one or more registers for storing status information of the one or more processing modules;
- one or more registers for storing control information comprising parameters for the operations for the one or more processing modules to perform with respect to the audio data;
- an input interface having inputs for receiving signals from an input transmission medium comprising a first communication medium and a second communication medium on which data is received from the audio system as a low voltage differential signal, and from a third communication medium on which a first clock signal is transmitted which corresponds to a transmission rate of bits of the data received on the first and second communication media;
- wherein the data received on the first and second communication medium as a low voltage differential signal defines a plurality of frames of input channels of audio and user data in a sequence over time, wherein each frame of the data corresponds to a period of time and comprises a plurality of channels of audio data and a channel of user data and terminated by a synchronization signal with a run length delimiter before each of the plurality of channels and before the synchronization signal, wherein the channel of user data carries requests for status information and control information, wherein each of the plurality of channels of audio data in the frame carries a plurality of bits of a different one of the input channels of audio data for the period of time of the frame, and wherein the synchronization signal comprises a run of zeros greater than a number of bits in each channel;
- the input interface processing the first clock signal received over the third communication medium to extract the data received on the first and second communication medium, the extracted data being output to a controller;
- the controller having an input receiving, from the input interface, the extracted data and:
- a. processing requests for status information in the extracted data received from the input interface to access the one or more registers for storing status information;
- b. processing control information in the extracted data received from the input interface to access the one or more registers for storing control information;
- c. processing digital audio data in the extracted data received from the input interface and directing the received digital audio data from the frame to the one or more processing modules for processing according to control information in the one or more registers for storing control information;
- an output interface having outputs for connection to an output transmission medium comprising a fourth communication medium and a fifth communication medium, on which data is transmitted to the audio system as a low voltage differential signal, and a sixth communication medium, on which a second clock signal is transmitted which corresponds to a transmission rate of bits of the data transmitted on the fourth and fifth communication media;
- wherein the data transmitted on the fourth and fifth communication medium as a low voltage differential signal defines a plurality of frames of output channels of audio and user data in sequence over time, wherein each frame of the data corresponds to a period of time and comprises a plurality of channels of audio data and a channel of user data, terminated by a synchronization signal, with a run length delimiter between the data of each channel and the synchronization signal, wherein the channel of user data carries reply information, wherein each of the plurality of channels of audio data in the frame carries a plurality of bits of a different one of the output channels of audio data for the period of time of the frame, and wherein the synchronization signal comprises a run of zeros greater than a number of bits in each channel
- the controller providing, in response to a request for status information in one frame received by the input interface, reply information to the output interface for transmission in a next frame output by the output interface to the audio system over the output transmission medium;
- the controller providing, in response to a request with control information in one frame received by the input interface, reply information acknowledging the request to the output interface for transmission in a next frame output by the output interface to the audio system over the output transmission medium;
- the controller providing, in response to operations to be performed on input digital audio data in one frame received by the input interface, output digital audio data from the one or more processing modules to the output interface for transmission in a next frame output by the output interface to the audio system over the output transmission medium;
- a clock generation circuit having an output providing the second clock signal for transmission on the sixth communication medium, and wherein the first clock signal received on the third communication medium and the second clock signal have a same first clock rate.