Connectors for audio data transfer

1. A signal controller for controlling transfer of signals between a host device and a peripheral device via a USB Type-C connector of the host device, the signal controller comprising:

a path controller for establishing signal paths between circuitry of the host device and contacts of said USB Type-C connector,

wherein the path controller is operable in at least first and second modes, wherein:

in the first mode the path controller establishes separate signal paths to each of at least first, second, third and fourth contacts of the USB Type-C connector, wherein a plurality of said signal paths are for transfer of analogue audio signal; and

in the second mode the path controller establishes a pair of signal paths to only a subset of said first to fourth contacts of the USB Type-C connector, wherein the pair of signal paths are for transfer of differential digital signals;

wherein, when entering the first mode, the signal controller is configured to determine a connection configuration for the peripheral device, wherein the connection configuration indicates whether each of the first to fourth contacts of the USB Type-C connector is connected to a microphone or a loudspeaker of the peripheral device, and wherein the path controller establishes the signal paths in the first mode based on the determined connection configuration,

further comprising a discovery module configured to monitor the electrical properties of at least one contact of the USB Type-C connector to determine a type of connection for that contact,

wherein the discovery module is configured to determine which of at least two predetermined additional contacts of the USB Type-C connector is a ground contact connected to a ground return for the peripheral device and the path controller is further operable to establish a ground path to said determined ground contact.

2. A signal controller as claimed in claim 1 wherein, in the first mode the path controller additionally establishes a separate analogue signal path to one of at least a fifth or sixth contact of the USB Type-C controller.

3. A signal controller as claimed in claim 1 wherein the discovery module is configured, when entering the first mode, to monitor the electrical properties of at least one of said first to fourth contacts of the USB Type-C connector to determine whether the respective contact is connected to a microphone or a loudspeaker of the peripheral device.

4. A signal controller as claimed in claim 1 wherein the signal controller is configured to determine the connection configuration based on the type of connection determined for at least one contact of the USB Type-C connector and a plurality of predetermined possible connection configurations.

5. A signal controller as claimed in claim 1 wherein the signal controller comprises a switch array connected to the USB Type-C controller, wherein the path controller controls the switch array to provide at least some of said signal paths in the first mode.

6. A signal controller as claimed in claim 5 wherein said switch array comprises a first set of switches, the first set of switches being operable, in the first mode:

in a first switch state to connect the first and second contacts to first and second signal paths respectively and to connect the third and fourth contacts to third and fourth signal paths respectively; and

in a second switch state to connect the first and second contacts to the third and fourth signal paths respectively and to connect the third and fourth contacts to the first and second signal paths respectively.

7. A signal controller as claimed in claim 1 wherein at least one of said signal paths in the first mode is a loudspeaker signal path for transfer of analogue audio signals from an amplifier of the host device to drive a loudspeaker of the peripheral device.

8. A signal controller as claimed in claim 1 wherein at least one of said signal paths in the first mode is a microphone signal path for transfer of audio signals received from a microphone of the peripheral device to audio processing circuitry in the host device.

9. A signal controller as claimed in claim 8 wherein at least one microphone signal path is an analogue signal path for transfer of analogue audio signals received from a microphone of the peripheral device, a digital signal path for transfer of digital audio signals received from at least one digital microphone of the peripheral device, or a signal path for audio signals received from a noise cancellation microphone and said audio processing circuitry comprises noise cancellation circuitry.

10. A signal controller as claimed in claim 1 wherein the path controller is further operable in a third mode to establish just two analogue signal paths to said first to fourth contact for transfer of left and right analogue stereo audio data to loudspeakers of a peripheral device.

11. An electronic device comprising:

a USB Type-C connector; and

a signal controller as claimed in claim 1 .

12. An electronic device as claimed in claim 11 further comprising an audio codec wherein the path controller is configured, in the first mode, to establish said signals paths between the USB Type-C connector and the audio codec.

13. An electronic device as claimed in claim 11 further comprising a USB controller wherein the path controller is configured, in the second mode, to establish said signals paths between the USB Type-C connector and the USB controller.

14. An electronic device as claimed in claim 11 wherein the electronic device is at least one of: a portable device; a battery powered device; a communications device; a computing device; a mobile telephone; a laptop, notebook or tablet computer; a personal media player; a gaming device; and a wearable device.

15. A signal controller as claimed in claim 1 wherein the USB Type-C connector comprises first and second rows of contacts and said first and second contacts are the central two contacts of the first row and said third and fourth contacts are the central two contacts of the second row.