Data controller, peripheral electronic device, and electronic device

Abstract

Embodiments of the present disclosure relate to methods and apparatus for peripheral device discovery, detection of orientation of connectors having multiple degrees of rotational symmetry, and provision of proper signal paths between a host device and a peripheral device. Some embodiments provide a feature impedance within a peripheral device that is coupled between rotationally symmetric contacts of a connector, thereby enabling detection of the orientation of the connector. The value of the feature impedance can be used in some embodiments to determine the type or model of the peripheral device. Some embodiments relate to enabling of proper signal paths for peripheral devices having transducers (e.g., speakers) that are coupled only to rotationally symmetric contacts of a connector, such as earphones implemented in a "balanced" configuration.

Description

[0001] This application is a divisional application of the application for patent filed on July 25, 2017, application number 201780057309.6, entitled "Connectors for Data Transfer". TECHNICAL FIELD

[0002] The field of representative embodiments of the present disclosure relates to methods, apparatuses or implementations related to or associated with connectors for data transfer between a host device and a peripheral device, in particular to bidirectional transfer of audio data channels, in particular transfer via a universal data connector or a multi-functional data connector. BACKGROUND

[0003] Many modern electronic devices have facilities for connection with external audio devices or peripheral audio devices. For example, mobile telephones, tablet computers, laptop computers, mp3 players, etc. are examples of electronic devices that can operate with peripheral audio devices, such as headsets, for example, external to and remote from the electronic device. Peripheral devices, such as headsets, can typically include a mono or stereo speaker for audio playback and possibly a microphone for voice communication.

[0004] Such external peripheral audio devices are often connected via a mating connector, such as a plug and socket arrangement. For example, many audio peripheral devices, such as headsets, have a socket plug for connection to a suitable jack socket on a host electronic device, such as a 3.5mm socket jack. A well-known arrangement for socket plugs and their associated sockets is TRRS (Tip-Ring-Ring-Sleeve) which has four contacts for left audio, right audio, microphone and ground. In one known arrangement, the tip (T) and first ring (R1) are used for left (L) and right (R) audio (e.g. left and right speakers), with the second ring (R2) being used for microphone (M) and the sleeve (S) being used for ground return (G). It will be appreciated that different arrangements for the left and right audio contacts, microphone contact and ground contact are also possible. This provides for two channel analog audio data transfer from the host device to the peripheral device and single channel analog audio data transfer from the peripheral microphone to the host device.

[0005] Some peripheral devices, such as headphones, can include one or more microphones arranged for noise cancellation, which can be remote from, and thus additional to, any microphone arranged for voice communication. For example, a headphone can include one or more additional microphones for detecting ambient noise, so that a compensation signal can be added to the playback audio to cancel the ambient noise.

[0006] Typically, noise cancellation is performed in the peripheral device itself. Thus, the electronics for generating the appropriate cancellation signal can be arranged in the headphone itself, for example in a dongle in a cable connecting the leads to the multiple microphones. Because the noise cancellation electronics require power, the housing for the electronics also needs to include a battery, making the housing relatively bulky and unwieldy, which can be undesirable for a headphone.

[0007] To avoid this, it has been proposed to arrange the noise cancellation electronics in the host device, for example a telephone handset. However, this would require an additional connection via the audio socket to allow the transfer of audio data from the noise cancellation microphone to the host device.

[0008] A number of solutions have been proposed, and one common theme among several of these solutions is the ability of the connector plug to be inserted into the connector socket in two or more different orientations. That is, the plug has at least two-fold rotational symmetry. See, for example, the Lightning (RTM) connector produced by Apple Inc., or the USB type-C connector. For ease of use, it is important that the connection is operable in either orientation. A direct implementation of this idea is to connect each signal path in the peripheral device to a plurality of pins in the connector plug at rotationally symmetric positions. Similarly, in the host device, the signal paths can be coupled to a plurality of rotationally symmetric pins in the connector socket. Thus, in this implementation, the orientation of the plug within the socket is independent of the host device.

[0009] However, in many implementations, it can be expected that more independent signal paths between the host device and the peripheral device will be required (as discussed above) than can be handled by simply providing a plurality of pins for each signal path. Thus, circuitry can be required to detect the orientation of the plug within the socket, so that the signals can be routed appropriately.

[0010] Furthermore, there are many various different peripheral devices that can be connected to a host device, each having different components and connection requirements. In some peripheral devices, for example, similar components can be connected to symmetrical pins of a connector, making it difficult to detect the type of connected peripheral device and the orientation of the plug within the jack. SUMMARY

[0011] According to an aspect of the application, there is provided a data controller for controlling data transfer between a host device and a peripheral device via a connector of the host device, the connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than 1. The data controller comprises a discovery module operable to detect the presence of one or more characteristic impedances on the contacts of the connector, and a path controller for enabling a signal path between circuitry of the host device and the contacts of the connector, the path controller being operable in at least a first mode and a plurality of second modes to enable the signal path between the circuitry of the host device and the contacts of the connector. The discovery module is operable to detect the presence of a first characteristic impedance on any one of a first contact and a second contact of the connector and a second characteristic impedance on any one of a third contact and a fourth contact of the connector, wherein the first, second, third and fourth contacts are different from one another. The path controller is configured to select the first mode or the plurality of second modes in dependence on detection of the first characteristic impedance. The path controller is configured to select one of the plurality of second modes in dependence on a value of the second characteristic impedance following selection of the plurality of second modes.

[0012] According to another aspect, there is provided a peripheral electronic device for connecting to a host electronic device via a connector thereof, the connector having a plurality of contacts arranged in a pattern having n-fold rotational symmetry, where n is an integer greater than 1. The peripheral electronic device comprises a pair of first characteristic impedances coupled to a first contact and a second contact of the connector, detection of the pair of first characteristic impedances causing the host electronic device to be placed in a first mode, one or more operational components coupled to at least a third contact of the connector, configured for at least one of transferring data to and receiving data from the host electronic device, and a second characteristic impedance separate from the one or more operational components, directly coupled to one of a pair of rotationally symmetric contacts of the connector, enabling the host electronic device to determine an orientation of the connector.

[0013] According to yet another aspect, there is provided a method of controlling data transfer between a host device and a peripheral device via a connector of the host device, the connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than 1. The method comprises: detecting the presence of a first characteristic impedance on any one of a first contact and a second contact of the connector, and selecting a first data transfer mode or a plurality of second data transfer modes in dependence on detection of the first characteristic impedance; detecting the presence of a second characteristic impedance on any one of a third contact and a fourth contact of the connector, wherein the first, second, third and fourth contacts are different from one another; and selecting one of the plurality of second modes in dependence on a value of the second characteristic impedance, wherein each of the plurality of second modes corresponds to a respective configuration of a signal path between the host device and the peripheral device.

[0014] According to yet another aspect, there is provided a data controller for controlling data transfer between a host device and a peripheral device via a connector of the host device, the connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than 1. The data controller comprises a path controller for enabling a signal path between circuitry of the host device and a contact of the connector. The path controller is operable to enable separate signal paths to each of at least a first contact, a second contact, a third contact and a fourth contact of the connector, wherein the signal paths to the first and second contacts are for transferring respective positive and negative audio signals for a first speaker of the peripheral device, and wherein the signal paths to the third and fourth contacts are for transferring respective positive and negative audio signals for a second speaker of the peripheral device.

[0015] Another aspect provides an electronic device comprising: a connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than 1; and a data controller as set out above.

[0016] Yet another aspect provides an electronic accessory device for connecting to a host electronic device via a connector thereof, the connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than 1. The electronic accessory device further comprises: a transducer coupled only to a first contact and a second contact of the connector, wherein the first and second contacts are positioned at rotationally symmetric positions on the connector.

[0017] An apparatus is provided in one aspect, comprising: an audio codec to provide audio signals to a peripheral device; a path controller to enable signal paths between the audio codec and contacts of a connector of a host device, the connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than one, the path controller operable to enable separate signal paths between a first amplifier of the audio codec and at least one first contact of the connector and between a second amplifier of the audio codec and at least one second contact of the connector, the at least one first contact and the at least one second contact positioned at rotationally symmetric locations on the connector; and a discovery module operable to detect the presence of a characteristic impedance on at least one contact of the connector, thereby determining an orientation of the connector of the peripheral device relative to the connector of the host device. The audio codec is operable in a first operating mode to provide audio signals via the first amplifier and is operable in a second operating mode to provide audio signals via the second amplifier. The path controller is operable to select between the first operating mode and the second operating mode in dependence on the orientation of the connector.

[0018] An electronic device is provided in yet another aspect, comprising: a connector having n-fold rotational symmetry, where n is an integer greater than one; and an apparatus as recited above.

[0019] An electronic device is provided in another aspect, comprising: an application processor; a wireless modem; a connector to connect the electronic device to an accessory device; an audio codec coupled to the application processor, the wireless modem, and the connector to at least one of provide audio signals to the connector and receive audio signals from the connector; and a first digital interface configurable to provide a first signal path to signals between the application processor and the connector. The audio codec comprises a second digital interface configurable to provide a second signal path to signals between the wireless modem and the connector via the audio codec. BRIEF DESCRIPTION OF DRAWINGS

[0020] For a better understanding of embodiments of the present disclosure, and to show how the same can be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which:

[0021] Figure 1 A USB Type-C connector arrangement is illustrated;

[0022] Figure 2 A USB Type-C audio socket adapter is illustrated;

[0023] Figure 3A peripheral device and host device with a connector arrangement according to one embodiment are illustrated;

[0024] Figure 4 A data controller according to one embodiment is illustrated;

[0025] Figure 5 A peripheral device and host device with a connector arrangement according to another embodiment are illustrated;

[0026] Figure 6a and Figure 6b A connector arrangement for a balanced headphone set is illustrated;

[0027] Figure 7a and Figure 7b Mechanisms for detecting the orientation of a connector and the type of peripheral device connected to a host device are illustrated;

[0028] Figure 8a and Figure 8b An alternative connector arrangement for a balanced headphone set is illustrated;

[0029] Figure 9a and Figure 9b A connector arrangement for yet another peripheral device is illustrated;

[0030] Figure 9c A connector arrangement for yet another peripheral device is illustrated;

[0031] Figure 10 A peripheral device and host device with a connector arrangement according to yet another embodiment are illustrated;

[0032] Figure 11 A flowchart of a method of device discovery and configuration according to one embodiment is illustrated; and

[0033] Figure 12 One embodiment of a host device is illustrated. DETAILED DESCRIPTION

[0034] The following description sets forth exemplifying embodiments according to the present disclosure. Other example embodiments and implementations will be apparent from the following description to those of ordinary skill in the art. Furthermore, it will be understood by those of ordinary skill in the art that various equivalents substitutions and modifications can be made to the embodiments discussed below, or combinations of the embodiments discussed below, and all such equivalents substitutions and modifications are to be considered as being encompassed within the present disclosure.

[0035] Embodiments of the present disclosure relate to methods and apparatus for peripheral device discovery, detection of orientation of connectors having multiple degrees of rotational symmetry, and provision of proper signal paths between a host device and a peripheral device. Some embodiments provide a feature impedance within a peripheral device that is coupled between rotationally symmetric contacts of a connector, thereby enabling detection of the orientation of the connector. The value of the feature impedance can be used in some embodiments to determine the type or model of the peripheral device. Some embodiments relate to enabling proper signal paths for peripheral devices having transducers (e.g., speakers) that are coupled only to rotationally symmetric contacts of a connector, such as earphones implemented in a "balanced" configuration.

[0036] A new compact 24-pin USB Type-C connector has recently been proposed. The USB Type-C connector is a reversible connector, i.e., it has a two-fold rotational symmetry and is designed to operate with a Type-C plug that can mate with a Type-C receptacle in either of the possible mating orientations. The Type-C connector is designed to be suitable for data transfer according to the current USB 3.1 specification for high data rate transfer and is particularly suitable, for example, for transferring digital data at high data rates, e.g., for video data transfer.

[0037] As used in the present disclosure, the term "USB Type-C" or simply "Type-C" shall be considered to mean a connector that is compatible with the USB Type-C Specification, available at the time of writing from the USB organization website: http: / / www.usb.org / developers / docs / "USB Type-C Cable and Connector Specification" version 1.2, March 25, 2016, the contents of which are incorporated herein by reference. The term Type-C shall be considered to mean any connector that can be compatible with the version 1.2 specification defined above or that can be compatible with future possible modifications of this specification. TM Cable and ConnectorSpecification" version 1.2, March 25, 2016, the contents of which are incorporated herein by reference. The term Type-C shall be considered to mean any connector that can be compatible with the version 1.2 specification defined above or that can be compatible with future possible modifications of this specification.

[0038] Accordingly, aspects of the present invention are described below with reference to USB type-C connectors. However, those skilled in the art will appreciate that the present invention is applicable to other similar existing or future connectors and in particular to any future rotationally symmetric connector (i.e., a connector having a plurality of pins arranged in a rotationally symmetric pattern). Accordingly, the present invention is not limited to USB type-C connectors unless explicitly stated in the appended claims.

[0039] Figure 1The principle of a USB Type-C connector 100 is exemplified. The connector has two rows of pins or contacts 101, with twelve pins in each row. Note that, as used in this specification, the term "pin" in connection with a connector shall mean an electrical terminal that can establish an electrical connection with a corresponding terminal of another connector when the connectors are properly mated, and the term "contact" shall mean the same. The pins are arranged such that the rows are (2-fold) rotationally symmetric. By convention, the pins in one row are identified as A1 to A12, and the pins of the other row are labeled B1 to B12. For ease of reference, the pins are numbered such that the pins of a Type-C receptacle, i.e. a jack or similar type of mating connector that can be provided in a host device for example, have the same numbering as the pins of a Type-C plug that can mate with the mating connector. The numbering of the pins of the receptacle can increase in a generally clockwise manner, as seen from a view looking into the mouth of the receptacle, i.e. as exemplified in Figure 1 Figure 1 Pin labeling for a view looking into the mouth of a Type-C receptacle is exemplified. For a Type-C plug, the numbering, as seen from a view looking into the plug, would instead increase in a counter-clockwise direction. Thus, the receptacle pin A3 would mate with the corresponding plug pin A3, or with pin B3 if the plug is inserted in a rotational orientation.

[0040] The pins of a Type-C connector can be provided at least partially surrounded by a guide 102, which can for example be a wall of a jack or some protective / guide sheath of a plug, which can also be rotationally symmetric and can for example have the form of a rounded rectangle.

[0041] As mentioned above, the USB Type-C connector is designed to be suitable for fast digital data transfer as well as power delivery, and can be seen as a universal data connector or multi-purpose data connector. While primarily envisioned for digital data transfer, the USB Type-C specification describes that stereo headphones can be connected to a host device via a Type-C receptacle of the host device by using a separate adapter with a receptacle jack for a standard 3.5 mm TRRS audio jack plug and a USB-Type-C plug. Appendix A of the USB Type-C specification describes this (Audio Accessory Adapter Mode).

[0042] Figure 2 An embodiment is exemplified how a USB Type-C adapter can be used to connect to a legacy peripheral audio device via a standard TRRS jack connector. Figure 2 ​An adapter 201 is illustrated that includes a Type-C compatible plug 202 and a jack receptacle 203 for receiving a 3.5mm TRRS jack plug. In use, the USB Type-C plug 202 can be connected to a USB Type-C receptacle 204 of a host device and the jack receptacle 203 can be mated with a jack plug (shown in dotted line) of a peripheral device such as a headset. In practice, the USB plug 202 of the adapter can be connected to the jack receptacle 203 via a length of suitable cable or both can be encased within a common body, for example a plastic moulding.

[0043] The four pins in the centre of each row of the Type-C connector are used in the audio accessory adapter mode, for example to provide a ground path and for data transfer. Pins A7 and B7 of the adapter plug 202 can be shorted together and connected to the tip contact of the jack receptacle. Pins A6 and B6 of the adapter plug 202 can be shorted together and connected to the first ring contact of the jack receptacle. This means that, when mated, the receptacle's pin B7 will be connected to the tip contact of the jack receptacle via either plug 202's pin B7 in one orientation or plug 202's pin A7 in the other orientation. Likewise, the receptacle's pin B6 will be in contact with the first ring contact. As is conventional, the tip contact is used for left audio data and the first ring contact is used for right audio data and so analog audio data for a left speaker can be transmitted from the host device via the receptacle's pin B7 (or equivalently pin A7) and analog audio data for a right speaker can be transmitted via pin B6 (or equivalently pin A6).

[0044] Pin A8 of plug 202 is connected to the sleeve contact and pin B8 of plug 202 is connected to the second ring contact. When plug 202 is mated with the receptacle, the receptacle's pin A8 will therefore be connected to the sleeve contact or the second ring contact depending on orientation with the receptacle's pin B8 being connected to the other of the two contacts. As is conventional, the second ring contact and the sleeve contact are used to receive a microphone signal and for the ground (referred to as the analog ground) of the accessory. However, different manufacturers have different standards and so it is conventional for the host device to be able to determine whether a contact is being used for a microphone signal or for ground. Therefore, conventional detection techniques can be applied in the host device to the signal paths established by the receptacle pins A8 and / or B8 to determine which path is the microphone path and which path is the ground.

[0045] For identification and discovery, the adapter 201 includes an impedance 205 connected between the common connections between the plug pins A5 and B5 and the plug pins Al, B12, Bl and A12, respectively. When docked, at least one of the plug pins Al, B12, Bl and A12 will be connected to ground, referred to as the digital ground. Thus, by detecting the impedance 205 presented on the receptacle contacts A5 and B5 when docked to the adapter 201, the host device can determine that it is operating in the audio accessory adapter mode, rather than other normal USB related modes.

[0046] Supervisory circuitry in the USB interface (not shown) can detect the impedance on the defined CC (configuration channel) contacts (pins A5 and B5) to sense the presence and type of attached USB peripheral. Thus, upon insertion of the type-C plug 202 into the receptacle 204 or upon power up or restart, the USB supervisory circuitry of the host device can perform the normal USB Type-C discovery. The standard cable detection (CD) function can be implemented by the host device to determine whether a plug is connected and whether it is connected to a DFP (downstream facing port) or a UFP (upstream facing port), as well as the orientation of the cable. This mechanism can rely on applying pull-up and pull-down resistors or current sources to the CC1 (A5) pin and CC2 (B5) pin and sensing various voltage points associated with these lines.

[0047] The USB type-C specification defines two characteristic impedances Rd and Ra (where Rd > Ra). As a downstream facing port, the USB system can effectively look for the characteristic impedance Rd or Ra being connected to the CC pins and, if it determines that a connection is present, the combination of impedances present at the CC pins can be used to determine the connection type and orientation. Thus, for example, an impedance Rd connected to one CC pin and the other CC pin open circuited defines that a UFP is attached and the orientation is provided by which CC pin is connected to Rd. Impedance Rd at one pin and impedance Ra at the other pin implies a supply cable attached a UFP, while impedance Ra at one pin and the other pin open circuited implies a supply cable without a UFP.

[0048] The audio accessory adapter mode can be initiated if both pins A5 and B5 are connected to the digital ground through an impedance less than the value Ra (where Ra is equal to 12 kilo-ohms). In Figure 2 In the embodiment shown in FIG. 1, each of the impedances 205 has a characteristic value less than 1.2 kilo-ohms.

[0049] Thus, the audio accessory adapter mode provides a method of operating peripheral audio devices using a USB Type-C connector to send and receive analog audio data. This method enables data transfer with peripheral devices having two speakers and a single microphone via a suitable adapter. However, it would be advantageous if the audio accessory adapter mode could be applied to control data exchange with a number of different peripheral devices. Furthermore, while adapters can be required to allow use with legacy peripheral devices, other peripheral devices can be provided with a USB Type-C connector using the same principles, allowing direct connection via a fixed cable, thus avoiding the need for a socket plug and socket socket.

[0050] Figure 3 A peripheral device 300 and a host device 400 are shown, according to one embodiment of the application, as are their respective connectors.

[0051] In this embodiment, the peripheral device 300 comprises a plurality of speakers 304, 305 and microphones 306, 307, 308 and is connected to the host device 400 via a pair of connectors 302 and 404. The host device 400 comprises headphone amplifiers 412, 413, 414, 415 suitable for driving the speakers and comprises microphone amplifiers 420, 422, 423, 424, 425 for buffering and amplifying signals from the microphones.

[0052] The input signals to the headphone amplifiers HPA, HPB, HPC, HPD are received via upstream signal paths from upstream circuitry which in turn can derive these signals from signals received via signal paths from still more upstream signal sources, possibly signal sources external to the host device via wired or wireless connections. The signal paths and processing from the original sources to the connectors can be configured so as to deliver appropriately derived signals to respective ones of the possibly multiple speakers.

[0053] The microphone amplifier output signals VM, MICA, MICB, MICC, MICD can be passed via downstream signal paths through downstream circuitry for processing or for onward transmission or storage via still more downstream signal paths. The signal paths and processing from the connectors pins through the microphone amplifiers to the ultimately desired signal destinations can be configured so as to derive signals from the appropriate one or more microphones and deliver these to respective ultimate destinations.

[0054] As illustrated, the headphone amplifiers and the microphone amplifiers can be co-integrated, possibly with ADCs or DACs or signal processing circuitry or other circuitry, on an integrated circuit 401, for example an audio codec integrated circuit.

[0055] In this embodiment, the peripheral device 300 is a set of headphones comprising a plurality of microphones. Thus, the device 300 comprises a left speaker 304, a right speaker 305 and a microphone 308, for example to acquire voice input from a user of the device 300. In addition, the peripheral device comprises two microphones 306, 307 - one for each speaker noise cancellation, for example microphones positioned to pick up the ambient noise signal at the left speaker and at the right speaker respectively or feedback noise cancellation microphones for the speakers. Thus, the device 300 is configured to perform noise cancellation as described with reference to Figure 2 Unlike the illustrated accessory, an accessory according to embodiments can comprise more than three audio transducers.

[0056] The device 300 further comprises a connector 302, which can be a USB type-C connector as previously defined. In some embodiments, the USB Type-C plug can be hardwired to the accessory body and thus the connection can comprise a fixed cable. However, in some embodiments, the connector 302 can form part of an adapter and have a device specific connector, such as a jack Figure 3 (not shown in the Figures) for connection to the body of the peripheral device. For consistency, the embodiments hereinafter will be described with reference to an accessory or peripheral device having a type-C plug connector (i.e. where the plug and connection are part of the accessory 300). The skilled person will understand that alternative arrangements discussed above are also possible.

[0057] In embodiments of the Figure 3 rather than joining the left speaker to the two pins A6 and B6 of the USB connector and the right speaker to the two pins A7 and B7 as described with reference to Figure 2 , the four pins are allowed to be connected individually.

[0058] For clarity, only a subset of the contacts of the connector 302 are shown. Other, non-illustrated contacts are either not used or are used for purposes other than transferring data to and from the illustrated components of the peripheral device 300, for example additional pins for power transfer, pins for high speed digital data, etc. These contacts are not germane to the present invention and are therefore omitted from the specification.

[0059] Each of the audio components of the device 300, i.e., the speakers 304, 305 and the microphones 306-308, is coupled between a respective contact of the connector 302 that is unique to that component and a common contact that can be held at a reference voltage, e.g., analog ground. For example, in the illustrated embodiment, the left speaker 304 is connected between pins A6 and A8; the right speaker 305 is connected between pins B6 and A8; the first noise cancelling microphone 306 is connected between pins A7 and A8; the second noise cancelling microphone 307 is connected between pins B7 and A8; and the voice microphone 308 is connected between pins B8 and A8. Pin A8 serves as the common contact. To avoid possible ground loops, this contact is not connected to any external ground at the accessory, but rather is connected via the connector to a suitable ground connection in the host device. In Figure 3 In the illustrated embodiment, the host device analog ground node AGND is provided with a suitable ground connection via the host device connector pin A8 via the switch 450.

[0060] The respective first terminals of the characteristic impedances 205a, 205b are connected to the CC pins A5 and B5. The respective second terminals of the characteristic impedances 205a, 205b are connected together and to the digital ground pins Al, Bl, A12 and B12. As explained above, these each have a value below 1.2 kilo-ohms, i.e., below Ra.

[0061] However, in addition, the peripheral device 300 can include a further characteristic impedance 312Rch coupled between the reference voltage pin B8 and the digital ground contacts Al, Bl, A12 and B12, which are tied together. The utility of this further characteristic impedance will be discussed in more detail below.

[0062] The host device 400 includes a receptacle connector 404 corresponding to the plug connector 302, and thus in some embodiments the receptacle 404 can be a USB type-C receptacle. When the plug connector 302 is mated with the receptacle connector 404, in one orientation of the plug relative to the receptacle, the receptacle pin A6 will mate with the corresponding plug contact A6 and thus be connected to the left speaker 304, and the receptacle contact B6 will mate with the corresponding plug contact B6 and be connected to the right speaker 305. In other possible orientations, instead, the receptacle contact A6 will mate with the plug contact B6 and be connected to the right speaker 304, and the receptacle contact B6 will mate with the plug contact A6 and be connected to the left speaker 304. Similarly, depending on the orientation, the receptacle pin A7 will mate with the plug pin A7 or B7 and be connected to the first or second noise cancelling microphone, with the receptacle pin B7 mating with the other contact.

[0063] The signal to be played back from the loudspeaker is typically already provided from some upstream audio signal source (e.g. an mp3 file) and can be digitally processed to provide a plurality of digital data streams, e.g. a left channel digital data stream and a right channel digital data stream. The signal path from this source via any digital-to-analogue conversion and headphone amplifier to the receiver contact must be configured so that the appropriate signal appears at each receiver contact, consistent with the identity of the loudspeaker connected to that contact via the connection to the plug contact, which can differ depending on the orientation of the connector.

[0064] Similarly, the signal path from the contact associated with the noise cancelling microphone signal to the downstream processing node via the microphone amplifier needs to be consistent with the identity of the microphone signal appearing on that contact, which can differ depending on the orientation of the connector.

[0065] The host device can therefore comprise a data controller for controlling the transfer of data between the host device and a peripheral device via a connector of the host device, such as a USB Type-C connector. The data controller can comprise a path controller or path control module for enabling signal paths between circuitry of the host device and contacts of the connector. The path controller is operable in a plurality of different modes to enable different signal paths between the host device 400 and a peripheral device 300 when the host device is connected to an accessory device requiring an analogue audio signal path.

[0066] The path controller can enable a signal path by operating one or more switches to establish a signal path between a component in the host device 400 and a pin of the connector (e.g. connecting an amplifier output to the pin, connecting an amplifier input to the pin, etc.). Alternatively, the path controller can enable a signal path by activating or deactivating a component that is permanently connected to a particular pin of the connector. For example, a signal path from an amplifier output can be enabled by activating the amplifier and deactivating other components connected to the pin.

[0067] Note that as used herein, the term "signal path" shall mean a path that is actually used or intended to be used to convey data, and audio signal paths shall be interpreted accordingly. Thus, such a signal path can be a path that conveys data to, for example, drive a loudspeaker or a readout microphone. A connection that enables a ground return loop - although it can be necessary for the operation of a component - shall not be considered a signal path for conveying data (although to avoid doubt, a microphone signal path can be a false ground, e.g. to a differential microphone amplifier input connected to the ground current return loop from a loudspeaker). Likewise, any connection that simply provides a supply voltage to a component does not constitute a signal path for conveying data (although to avoid doubt, a microphone signal path can be a phantom power supply, i.e. the power supply current is provided via a substantial source impedance, the voltage across which is modulated according to the microphone signal, which is common for analog electret microphones).

[0068] It will also be appreciated that because contacts A6 and B6 and contacts A7 and B7 are no longer shorted together, uncertainty about the orientation of the plug relative to the receptacle requires some sort of electrical determination method, after which the path controller can establish the appropriate signal paths. Thus, the host device can be configured to determine a connection configuration for the peripheral device, i.e. an indication of whether pins A6, A7, B6 and B7 are connected to loudspeakers or microphones of the peripheral device.

[0069] Thus, the host device or its data controller can comprise a discovery module or discovery controller configured to monitor the electrical performance of at least one contact of the receptacle connector 404 of the host device to determine a connection type for said contact. The connection configuration can then be determined based on the determined connection type for the at least one contact of the connector and the predetermined plurality of possible connection configurations.

[0070] In one embodiment, pin A8 of the plug connector 302 of the accessory device can be used for the voice microphone 308 and pin A8 is used for the common ground return loop pin. In one embodiment, the connections in the accessory device 300 can be constrained such that only one pre-defined arrangement with respect to the ground return loop pin is allowed. In other words, the set of possible configurations for the allowed accessory device, i.e. the arrangement of loudspeakers and microphones in the accessory and their connection to the type-C plug, can be limited to, for example, only one allowed configuration, e.g. illustrated as the arrangement of the accessory device 300 in Figure 3 This can thus limit the set of possible connections to, for example, only two possibilities, due to the two possible mating orientations of a type-C plug to a type-C receptacle.

[0071] In such embodiments, in use, the host device can determine which of the receptacle pins A8 or B8 appears to be directly connected to the common ground loop connection of the speaker and the microphone of the accessory device rather than appearing to be connected via the impedance of the microphone 308, and thus determine the relative orientation of the plug.

[0072] The codec circuit 401 thus includes microphone detection blocks (MICDET) 430, 431 coupled to pins A8 and B8 in the receptacle connector 404. The MICDET blocks can be employed during power-up or start-up to identify the presence of a voice microphone on pin A8 or B8, and then can be deactivated to not interfere with the microphone signal.

[0073] The codec additionally includes microphone bias circuits (MICBIAS) 440, 441 and a voice microphone (voice MIC) amplifier 420 having a pair of differential inputs coupled to the same contacts as the MICDET blocks. Depending on the decision made by the MICDET blocks, the MICBIAS circuits can be used to provide the necessary bias voltage to allow the voice microphone 308 to operate without a separate power supply in the accessory device 300.

[0074] The codec additionally includes a voice microphone (voice MIC) amplifier 420 comprising a pair of differential inputs coupled to the same contacts A8, B8 as the MICDET blocks. This amplifier provides an output signal VM derived from the voltage difference between the two contacts A8 and B8. The magnitude of this difference signal is not affected by which of the two pins is connected to which terminal of the voice microphone; only the polarity will change, and this can be corrected appropriately in downstream signal processing.

[0075] The differential nature of the microphone amplifier, and the selective activation and deactivation of the MICDET and MICBIAS blocks, means that no series switch is required on the connection between the pins A8, B8 and the voice microphone amplifier.

[0076] As mentioned above, the host device pin A8 or B8 that is determined by the MICDET circuitry to be connected to the common ground loop contact of the accessory device can be connected to ground, to the analog ground node AGND of the host device, via one pole or the other of a switch 450.

[0077] It is also noted that any common ground loop voltage appearing on the respective host device connector contact A8 or B8 can be passed via switch 451 as a headphone feedback signal HPFB to any of the headphone amplifiers 412-415 to effect such voltage drops, e.g. due to microphone or speaker loop ground currents through the on-resistance of switch 450, will be removed from the signal provided to the speakers 304, 305.

[0078] In the above embodiments, the connections in the accessory device 300, i.e. the arrangement of the speakers and microphones in the accessory and their connection to the type-C plug, are considered to be limited, e.g. to only one allowed configuration, e.g. exemplified as Figure 3 the arrangement of the accessory device 300 in

[0079] However, if a wider range of possibilities is to be allowed, e.g. some other mix of speakers and microphones, other electrical measurements can be needed, say from other contacts to a determined ground line.

[0080] In this regard, it can be seen in the embodiment exemplified in Figure 3 the needle B7 of the receptacle connector 404 is directly coupled to several components within the codec 401. For example, the needle B7 is coupled to the output of the amplifier 414, to the headphone detect (HPDET) block 604, to the respective microphone bias (MICBIAS) block 444, to the microphone detect circuitry 434 and to the input of the microphone amplifier 424. The needle B7 can also be connected to one needle of the USB PHY block 310 which can be activated to allow operation in standard USB mode when connected to an accessory requiring the interface or be deactivated for operation in audio accessory adapter mode. It is noted that in the exemplified embodiment each of these components can be permanently connected to the B7 needle, there is no switch in the area 402 for decoupling them. The number of different components on this line exemplifies the number of different signals sent or received through B7 depending on the type of peripheral device coupled to the receptacle connector 402 and the different possible orientations of the plug connector 302 within the receptacle connector 402.

[0081] For example, the HPDET block 464 can be used to test the connection on the B7 pin and to allow a determination to be made as to whether the component connected to the plug connector B7 pin is a speaker or a microphone. The HPDET block 464 can for example inject a known current into the pin B7 and measure the resulting voltage with a ground return pin connected to ground via the host connector pin A8 or B8, via the switch 450. The current applied can be small and applied gradually to avoid audio artifacts. Other such methods are known to those skilled in the art.

[0082] In the illustrated embodiment, where the peripheral device 300 is a set of headphones having a plurality of microphones, the connected component is the noise cancelling microphone 307, i.e. a microphone arranged to pick up ambient noise in the vicinity of the left speaker 304. The MICBIAS circuit can therefore be activated to provide a bias voltage to the microphone 307, and the error amplifier can also be activated to receive a noise signal output by the microphone 307 superimposed on the bias voltage on this line. The headphone amplifier can be deactivated so as not to drive a signal to the microphone or to prevent a substantial loading on this line.

[0083] A similar arrangement exists for the A7 pin, which in the illustrated embodiment is coupled to another noise cancelling microphone 306. The A7 pin is therefore coupled to the output of another amplifier 412, a headphone detect (HPDET) block 462, a corresponding microphone bias (MICBIAS) block, a microphone detect block 432 and an input of a microphone amplifier 422. The A7 pin can additionally be coupled to one pin of the data interface block (XL / UART) or USB PHY 310. The HPDET block 462 can therefore be able to test the connection on the A7 pin and determine whether the component connected to the plug connector A7 pin is a speaker or a microphone.

[0084] In the illustrated embodiment, the B6 pin of the receptacle connector 402 is also connected to several components within the codec 401, including the output of the headphone amplifier 415, a headphone detect (HPDET) block 465, a corresponding microphone bias (MICBIAS) block 445, a microphone detect block 442 and an input of a microphone amplifier 425. The corresponding B6 pin in the plug receptacle 302 is coupled to the right speaker 305 of the peripheral device 300, so in operation this HPDET block is able to detect the presence of a speaker on the B6 pin. The amplifier 415 can therefore be activated to output an analogue audio signal through the signal path via the pin B6 and drive the right speaker. The microphone bias (MICBIAS) block 445 can then be deactivated to avoid loading the signal line.

[0085] The A6 pin of the receptacle connector 402 is connected to a similar component within the codec 401 for driving the left speaker 304 of the peripheral device 300.

[0086] In addition to these components, the codec 401 can include circuitry 470 (JACKDET) to detect impedance on defined CC (configuration channel) contacts (pins A5 and B5) to sense the presence and type of attached peripheral device. Thus, upon plug insertion into the receptacle 404 or upon power up or restart, the codec 401 can perform a regular USB Type-C discovery. Standard cable detection (CD) functionality can be implemented by the host device in order to determine whether a plug is connected, and whether it is connected to a DFP (downstream facing port) or to a UFP (upstream facing port), as well as the orientation of the cable. This mechanism can rely on applying pull-up and pull-down resistors or current sources to the CC1 (A5) pin and CC2 (B5) pin and sensing the respective voltage points associated with these lines. In the illustrated embodiment, the codec 401 detects the presence of characteristic impedances 205a and 205b (< Ra) on both the A5 pin and the B5 pin, and is able to enter the audio accessory adapter mode. In other embodiments, this standard USB Type-C discovery can be performed by circuitry within the USB controller, which can then communicate the results to the codec. Detection of removal of impedance from these pins (anticipating removal of the plug from the receptacle) can be made by the JACKDET within the codec to avoid latency in communication and the resulting pop and click upon removal.

[0087] Figure 4 A data controller is illustrated that includes a path controller 560 and a discovery module 550.

[0088] The discovery controller or discovery module 550 can be configured to issue detection control signals to various detection blocks (such as the HPDET block or the MICDET block) within the codec 401 to instruct them to generate or sense voltages or currents, and can be further configured to receive data 552 indicative of impedances connected to or between various nodes in response. The discovery module 550 also includes a data storage module 555 that is configured to contain data representative of a plurality of predefined accessory configurations (i.e., including variations caused by relative rotation of the connectors) as can be observed from the host connector. The discovery module 550 can also be configured to infer from these indicative responses which of the possible accessory and connector configurations are currently connected, and to communicate this information as discovered configuration data 553 to the path controller 560.

[0089] In some embodiments, the data storage module 555 can comprise a lookup table, and the discovery module 550 can comprise digital logic circuitry to perform logic operations necessary to determine the attachment and connector configuration from the received data 552 in comparison to the data stored within the lookup table. In other embodiments, detection control signals or inference logic can be implemented on programmable controller circuitry, and the data storage module 555 can contain code for execution by the programmable controller, e.g., incorporating appropriate if...then statements or case statements, that is coded or parameterized to compare impedance detection results to pre-defined attachment configuration possibilities in the code.

[0090] The path controller 560 receives the discovered configuration data 553 from the discovery module 550, and based on the discovered configuration data 553 along with use case data 571, configures various circuitry to enable appropriate signal paths for outputting data to or receiving data from the attachment. For example, for data 561 from an audio signal source can enable a signal path to provide appropriate signals 562 for output transducers, such as speakers, within the attachment. Alternatively or additionally, for signals 563 from input transducers, such as microphones, within the attachment can enable a signal path to provide appropriate data 564 to an audio signal sink within the host device. In some embodiments, the signal paths controlled by the path controller can also allow output signals 562 to include components from input signals 563, e.g., to provide a telephone sidetone signal or echo cancellation.

[0091] Audio signal source data 561 can be provided from circuitry within the host device. For example, voice data or music data can be stored within memory circuitry or received from a local or telecommunication wireless network link via wireless controller circuitry. Audio signal sink data 564 can be supplied to circuitry within the host device. For example, incoming voice or music can be recorded, stored within memory circuitry, or can be relayed to some local or telecommunication wireless network via a wireless modem.

[0092] Use case data 571 can be provided directly from an application processor (not illustrated) of the host device or via user input, such as a touch screen or a push button, from an application processor (not illustrated) of the host device. This use case data can, for example, request that certain audio data included within data 561 be rendered via speakers within the attached attachment in mono or stereo, or can, for example, request that signals from certain microphones be forwarded to an audio sink within the processor circuitry for noise cancellation.

[0093] The path controller module 560 can include a path control module 570 that receives the discovered configuration data 553 from the discovery module and generates control data or signals to various circuitry within the possible signal paths based on the discovered configuration data 553 along with user instance data 571 to enable the appropriate subset of signal paths. These control signals can include one or more of: enable or disable signals to the output amplifier 584 or input amplifier 585; and control data for signal switch circuitry 582, 583, e.g., analog or digital switch matrices or multiplexers, etc., e.g., using MOS pass gates or digital regular logic. The control signals can include configuration data for a programmable processor 581, e.g., a digital signal processor, e.g., to determine the geographic location of the respective audio data stream, possibly before or after other signal processing.

[0094] In some cases, the path controller can establish one path through a switch 586, 587 in the path between the amplifier and the connector. For example, these switches can be positioned within the area 402 illustrated in Figure 3

[0095] The path controller can also issue control signals to enable or disable bias blocks, e.g., MICBIAS blocks. It can also enable or disable ground switches, e.g., to AGND.

[0096] The discovery module 550 and path controller 560 can be integrated in the audio codec 401, or can reside at least partially within other components of the host device 400. For example, the data signal processor 581 can at least partially comprise a separate integrated digital signal processor circuit 565 in communication with the audio codec 401, which can process or provide audio data signals to or from the audio codec in either direction. The identification of the signals it provides to the codec can be configured by commands sent from the path control module 570 within the codec to this separate integrated circuit.

[0097] Returning to Figure 3 , the voice microphone 306 is connected between accessory pins A8 and B8, and there is no connection to ground within the accessory 300. Thus, by applying voltage or current to only these pins A8 and B8, it is not apparent which pin is connected to the common ground return of the speaker. The polarity of the microphone's connections can be inferred by some asymmetry in the voltage current characteristics of known models of microphones, but this is not possible for the various microphones that different manufacturers can use in different models of accessories.

[0098] ​To infer the polarity of the connection of the connector, the controller can thus cause the HPDET block and the MICDET block to cooperate. For example, the HPDET block 463 or 465 can inject a current into the common ground loop via one of the speakers, while the receiver pin B8 is grounded, e.g., by controlling the switch 450, and the voltage on pin A8 is monitored by the MICDET 430. If the host device pin A8 is connected to the accessory's common ground loop, i.e., the accessory pin B8 is mated with the host pin A8, then a small voltage will appear on pin A8. However, if the host pin A8 is connected to the other terminal of the voice microphone 306, i.e., the accessory pin A8 is mated with the host pin A8, then the injected current will have to pass through the microphone 308 before it can reach AGND, thus a proper voltage will be generated on the host pin A8. Thus, the polarity of the connection can be determined by performing this procedure on both pins A8 and B8 in turn and comparing the voltage on the pin that is not connected to ground. Alternatively, the procedure can be performed on a single pin, and the voltage on the pin that is not connected to ground can be compared to a predetermined threshold.

[0099] Many other similar possible arrangements are possible, e.g., injecting a current into pin A8 or B8 and using the pin connected to the speaker to monitor any resulting voltage drop across the microphone. Thus, all of these methods rely on accessing one terminal of the microphone via the common ground loop connected to at least one speaker.

[0100] Figure 5 Different connections of an accessory or peripheral device 500 to a host device 400 are illustrated. In this embodiment, the peripheral device 500 comprises a pair of headphones, each connected in a balanced configuration. A balanced headphone connection configuration is characterized by each of a pair of terminals being connected independently to each of the speaker voice coils, as opposed to Figure 3 In contrast to the embodiment of Figure 3 In the embodiment of

[0101] The two terminals of a speaker's voice coil connected in a balanced configuration can be driven by a pair of signals of equal magnitude but opposite polarity referenced to some reference voltage, which can be ground or some other reference (e.g., a mid-supply rail). This connection has a number of benefits. For a given supply voltage, the voltage across the coil can be doubled, thus increasing the maximum signal that can be applied, and thus the acoustic output power. Symmetrical output voltage swings can also reduce common mode electromagnetic interference (EMI), and symmetric output impedances presented by the amplifier to the drive leads can also help reduce susceptibility to external EMI.

[0102] However, in some applications the speaker drive voltage can not be symmetric to obtain other benefits, such as various single-supply class G or class H implementations in which the supply voltage of the drive amplifier can vary according to the signal level to reduce power consumption, but it is desired that the signal swing span the supply voltage range present at any given time. Thus, the common mode voltage can vary to, for example, half of the time-varying supply voltage. In other applications, such as in a switched mode power supply (SMPS) amplifier topology, one amplifier can operate to drive only one terminal of the voice coil at any time and ground the other, switching these connections when the signal crosses zero voltage and its polarity is reversed, rather than always connecting the same terminal to ground. Still other applications can operate under a mix of multiple modes.

[0103] Thus, to enable such a drive configuration to operate, the earpiece 500 of this embodiment includes the left speaker 508 coupled between pins A6 and A7 of the connector 502 of the accessory device and the right speaker 510 coupled between pins B6 and B7. The earpiece 500 can additionally include the voice microphone 506 coupled between A8 and B8. As before, the earpiece 500 can also include the feature impedances 205a, 205b on the A5 and B5 pins. The feature impedances are each less than 1.2 kilo-ohms (i.e., less than Ra), such that their detection causes the interface to enter the audio accessory adapter mode.

[0104] In this arrangement, with pins A6 / A7 and B6 / B7 both connected to speakers, the codec 401 can be caused to operate in a mode in which each of the amplifiers 412, 413, 414, 415 used to output signals to the earpiece 500 is active, while each of the MICBIAS circuits 442, 443, 444, 445 (with the possible exception of the biasing circuit 440 or 441 for the voice microphone 506) and the corresponding microphone amplifiers are deactivated.

[0105] Figure 6a and Figure 6b The connection of the accessory 500 to the host device 400 is illustrated in both relative orientations of the host device connector 404 and the accessory connector 502.

[0106] In Figure 6aIn the orientation illustrated in FIG. 6, host device connector pin A6 mates with the corresponding pin B6 of the accessory connector, pin A7 mates with B7, and so on. Left speaker 508 is driven by the signal applied between host pin A6 and adjacent host pin A7, and right speaker is driven by the signal applied between adjacent host pins B6 and B7. Microphone bias can be applied to host pin B8, which also carries the signal superimposed on it by voice microphone 506, with host pin A8 carrying only the ground return current from the microphone.

[0107] In the orientation illustrated in FIG. 6, host device connector pin A6 mates with the corresponding pin B6 of the accessory connector, pin A7 mates with B7, and so on. Left speaker 508 is driven by the signal applied between host pin A6 and adjacent host pin A7, and right speaker is driven by the signal applied between adjacent host pins B6 and B7. Microphone bias can be applied to host pin B8, which also carries the signal superimposed on it by voice microphone 506, with host pin A8 carrying only the ground return current from the microphone. Figure 6b In the orientation illustrated in FIG. 6, host device connector pin A6 mates with the corresponding pin B6 of the accessory connector, pin A7 mates with B7, and so on. Left speaker 508 is driven by the signal applied between host pin A6 and adjacent host pin A7, and right speaker is driven by the signal applied between adjacent host pins B6 and B7. Microphone bias can be applied to host pin B8, which also carries the signal superimposed on it by voice microphone 506, with host pin A8 carrying only the ground return current from the microphone.

[0108] In the orientation illustrated in FIG. 6, host device connector pin A6 mates with the corresponding pin B6 of the accessory connector, pin A7 mates with B7, and so on. Left speaker 508 is driven by the signal applied between host pin A6 and adjacent host pin A7, and right speaker is driven by the signal applied between adjacent host pins B6 and B7. Microphone bias can be applied to host pin B8, which also carries the signal superimposed on it by voice microphone 506, with host pin A8 carrying only the ground return current from the microphone. Figure 5 In the orientation illustrated in FIG. 6, host device connector pin A6 mates with the corresponding pin B6 of the accessory connector, pin A7 mates with B7, and so on. Left speaker 508 is driven by the signal applied between host pin A6 and adjacent host pin A7, and right speaker is driven by the signal applied between adjacent host pins B6 and B7. Microphone bias can be applied to host pin B8, which also carries the signal superimposed on it by voice microphone 506, with host pin A8 carrying only the ground return current from the microphone. Figure 3 In the orientation illustrated in FIG. 6, host device connector pin A6 mates with the corresponding pin B6 of the accessory connector, pin A7 mates with B7, and so on. Left speaker 508 is driven by the signal applied between host pin A6 and adjacent host pin A7, and right speaker is driven by the signal applied between adjacent host pins B6 and B7. Microphone bias can be applied to host pin B8, which also carries the signal superimposed on it by voice microphone 506, with host pin A8 carrying only the ground return current from the microphone. Figure 3 The described method of the embodiment of FIG. 6 for determining relative connector polarity is adapted to determine relative connector polarity by exciting or monitoring a combination of microphone terminals or speaker terminals (i.e., by exciting or monitoring pins A6, A7, A8 and B6, B7, B8).

[0109] A resistor 312 is therefore included to provide a characteristic impedance Rch between one terminal of the microphone and pins Al, Bl, A12 and B12, which are tied together and mate with corresponding pins of the host device connector and are coupled to the digital ground of the host device. This resistance therefore provides an asymmetric connection to digital ground, which can be detected by exciting pin A8 or B8 relative to digital ground pins Al, etc.

[0110] Figure 7a And Figure 7b A method of detecting the presence of characteristic impedance 312 Rch is illustrated.

[0111] Figure 7a When the connector is mated with the corresponding pins of a connection (e.g., as in FIG. 6), the characteristic impedance 312 Rch is detected. Figure 6adetection when the connector is connected with a pair of pins that are in a rotationally symmetric arrangement (e.g., A6 vs. B6, etc.). In the first measurement, voltage source VT1 can be applied to pin B8 of the host device connector, such that Rmic (the impedance of the microphone 506) and Rch will provide a voltage divider, and a divided voltage will appear on pin A8. In the second measurement, voltage source VT1 can be applied to pin A8. Assuming that there is no substantial loading of pin A8 due to sensing equipment or other circuitry attached to pin B8, the voltage monitored on B8 will be substantially equal to VT1.

[0112] Figure 7b detection when the connector is connected with a pair of pins that are in a rotationally symmetric arrangement (e.g., A6 vs. B6, etc.). If the same measurement sequence is repeated, in the first measurement, where voltage source VT1 is applied to pin B8 of the host device, there is no voltage divider effect, and the voltage monitored on A8 will be equal to VT1. In the second measurement, where voltage source VT1 is applied to pin A8, Rmic and Rch will provide a voltage divider, and a divided voltage will appear on pin B8.

[0113] Thus, based on which of the first or second measurements delivers a possible divided voltage, i.e., a non-zero voltage across the microphone, the two possible orientations of the connector can be detected.

[0114] The voltage between pins A8 and B8 can be measured separately in the two measurements as respective single differential voltages, and then each differential voltage is digitized, and then the two digitized voltages are subtracted for comparison. Alternatively, the voltage on A1 can be stored as an analog voltage from the first measurement, and then subtracted from the voltage on pin B1 in the second measurement before digitization. In each case, the measurement result on which the decision is based can be obtained by directly detecting the voltage difference between the two node voltages simultaneously or sequentially, rather than measuring the two voltages separately for each measurement and digitizing them and then subtracting them downstream.

[0115] Based on these measurements and detection decisions, the discovery module 550 can control the path controller 560 to alter the upstream signal path or processing to compensate for the interchange of the connector nodes that will be driven or monitored.

[0116] Similar measurement techniques can apply controlled current rather than voltage. Further measurements can also be made across these and other pins to detect the presence and connection of a speaker or microphone of an accessory.

[0117] Typically Rch can be much larger than Rmic to avoid significant coupling of any differences between the host analog ground and digital ground. Rch can be in the range of 10 kilo-ohms to 1 mega-ohm, for example, while a nominal Rmic value can be about 300 ohms.

[0118] Figure 8a and Figure 8b The connection of another embodiment is illustrated, in which the accessory comprises components connected to the connector in a different wiring than Figure 5 and Figure 6a and Figure 6b the accessory illustrated in Figure 1 . In this case, the left speaker is connected to the accessory connector pins A6 and B7, i.e. to a pair of pins arranged opposite to each other in the connector, as illustrated in , instead of a pair of pins arranged adjacent, such as A6 and A7. Similarly, the right speaker is connected between another pair of opposite arranged pins B6 and A7.

[0119] In the relative orientation of the two connectors illustrated in Figure 8a , the pin A6 of the host device connector is mated with the corresponding pin A6 of the accessory connector, the pin A7 with A7, etc. In the relative orientation of the two connectors illustrated in Figure 8b , the pin A6 of the host device connector is mated with the pin B6 of the accessory connector, which is arranged rotationally symmetrically, the pin A7 with B7, etc. The effect on the speaker connection is similar to the one illustrated in Figure 6a and 6b : the left and right speakers are interchanged with respect to the connection to the host connector, and this change will need to be compensated in the upstream path controller.

[0120] An accessory like this would still require additional components, such as the feature impedance Rch shown in Figure 7a and Figure 7b to allow detecting the relative orientation of the otherwise symmetrically connected components.

[0121] Figure 9a and Figure 9b The connection of an accessory according to another embodiment is illustrated, in which the accessory comprises components connected to the connector in a different wiring than the accessories described above. In this case, the left speaker is connected to the accessory connector pins A6 and B6, i.e. to a pair of pins arranged diagonally opposite to each other or in rotationally symmetric positions around the rotationally symmetric axis of the pin arrangement. Similarly, the right speaker is connected between another pair of rotationally symmetrically arranged pins B7 and A7.

[0122] In the relative orientation of the two connectors illustrated in Figure 9a , the pin A6 of the host device connector is mated with the corresponding pin A6 of the accessory connector, the pin A7 with A7, etc. In the relative orientation of the two connectors illustrated in Figure 9b , the pin A6 of the host device connector is mated with the pin B6 of the accessory connector, which is arranged rotationally symmetrically, the pin A7 with B7, etc. The effect on the speaker connection is different from in Figure 6a andFigure 6b As illustrated in the middle: each of the left and right speakers is still connected between the same respective pair of pins. However, the connections across each speaker are reversed. Thus, the acoustic output of each still corresponds to the same channel, but both will have opposite phase. In some applications, this can be considered acceptable.

[0123] However, note that if a microphone is present, some discovery of its orientation will still be needed to bias and monitor it properly, so the characteristic impedance Rch can still be included in the accessory, and a similar discovery measurement process as described above with reference to Figure 7a and Figure 7b is performed.

[0124] In some embodiments, a set of resistors can be provided in the accessory, controlled by the button or similar, to transmit a user command for volume increase or decrease from the accessory to the host device. These resistors can be placed in parallel with the microphone, if present, or instead of the microphone, e.g. between pins A8 and B8, as illustrated in the middle of Figure 9c The polarity of the connections of these resistors is not important. Thus, in embodiments without a microphone, the characteristic impedance can be omitted.

[0125] The discovery method mentioned above determines to which pin the characteristic impedance Rch is connected. Its value can also be measured by applying a current and voltage to the non-ground pin to which Rch is connected, and monitoring the voltage or current. The value of this resistor can be arranged to distinguish different possible models or types of accessories. For example, a number of non-overlapping bands of resistance values can be defined, where each band of resistance values corresponds to a different model or type of accessory. By determining in which band the characteristic impedance value falls, the model or type of accessory can be determined.

[0126] Figure 10 The connection of a different accessory or peripheral device 600 to the host device 400 is illustrated. In this embodiment, the peripheral device 600 is a digital processing device, such as an electronic sensor (e.g. a light sensor, a fingerprint sensor, etc.), a health monitor, or any other type of peripheral device, and comprises a processor 604. The processor 604 is coupled to two pins A6 and A7, and A8 and B8. The processor can comprise programmable circuitry for processing sensor signals. The processor can additionally or alternatively comprise processing circuitry whose functionality is fixed in design.

[0127] In host device 400, USB data controller 310 can be activated to drive or monitor pins A6 and A7 of connector 404. Other components in codec 401 that are coupled to pins A6 and A7 can be deactivated to prevent them from interfering with data signals from controller 310. Pins A9 and B9 of a connector (not illustrated) can be used to provide power to a processor or USB interface therein as allowed by the USB Type-C standard mentioned above. Alternatively, pins A8 or B8 of connector 404 can be coupled to a disableable supply connection 481 or 482, while the other of A8 or B8 is connected to an analog ground via ground switch 450 to provide some or all power and ground to processor 604.

[0128] In other embodiments, codec 401 can include an additional digital interface 483 that can provide a unidirectional digital interface and a bidirectional digital interface to processor 604 via accessory pins A6 and A7 (which can be pins A6 and A7 in one orientation of the accessory, or pins B6 and B7 in another orientation of the connector). This digital interface can be in a variety of formats, such as Soundwire XL or a Universal Asynchronous Receiver / Transmitter (UART). Pins A8 or B8 of connector 404 can be coupled to a disableable supply connection 481 or 482, and the other of A8 or B8 is connected to an analog ground via ground switch 450 to provide some or all power and ground compatible with the voltage on digital interface 483 to processor 604.

[0129] This digital interface 483 can provide a path to or from an accessory to an application processor, or to a wireless modem that leads to lower latency than a USB controller alone, especially if, for example, the USB controller is integrated in one application processor and needs to relay its data through that application processor. In some embodiments, this interface can be a USB interface in addition to or instead of USB PHY 310.

[0130] Thus, in such embodiments, the electronic device will comprise an application processor, a wireless modem, a connector for connecting the electronic device to an accessory device (such as a USB type-C connector, another rotationally symmetric connector, or any other connector), an audio codec providing audio signals to and / or receiving audio signals from the connector, and a first digital interface configurable to provide a first signal path for signals between the application processor and the connector. The first digital interface can be a USB interface, such as a USB PHY. The first digital interface can be integrated on the application processor, or provided on a separate integrated circuit (such as a power management or power delivery integrated circuit, or a dedicated digital interface integrated circuit). The wireless modem can also be integrated on the application processor.

[0131] The audio codec is coupled to the application processor, the wireless modem, and the connector, and comprises a second digital interface configurable to provide a second signal path for signals between the wireless modem and the connector via the audio codec. The second signal path can have a lower latency than the first signal path. The second signal path can be suitable for use, for example, when the wireless modem receives a wireless communication signal comprising an audio component (such as speech, for example if the electronic device is making a voice call via a mobile communication network).

[0132] The second signal can additionally be passed via the application processor. However, in this case, it can not make use of any audio processing software implemented in the application processor in order to achieve lower latency.

[0133] The first digital interface and the second digital interface can be connected to at least one common contact (and possibly multiple common contacts) on the connector.

[0134] The device 600 additionally comprises feature impedances 205 on the A5 and B5 pins. The feature impedances 205 are each less than 1.2 kilo-Ohms (i.e. less than Ra), such that their detection causes the interface to enter the audio accessory adapter mode.

[0135] According to embodiments, the device 600 further comprises a feature impedance Rch312 coupled between each of the power contacts Al, Bl, A12, and B12 (which are tied together) and the reference voltage pin B8. This additional feature impedance can be used to discover the relative orientation of the connector in a similar manner to that described above, and the value of the impedance in a particular accessory can be used to distinguish accessory types according to which of a predetermined set of resistance groups the measured impedance lies in.

[0136] Some embodiments of the host device 400 can allow the interface 483, e.g. a USB interface 483, to operate in conjunction with an accessory device that does not operate in an audio accessory mode, thus not having a characteristic impedance 205 less than Ra on both A5 and B5 pins, e.g. a plain USB headset without analog signal functionality. The interface 483 can be selected by an instruction received from the application processor, or can be selected by the codec recognizing that it is being asked to communicate audio data with a pure digital accessory.

[0137] Figure 11 A discovery and configuration method that can be employed by a host device according to an embodiment of the application is illustrated.

[0138] The method starts in step 1100. For example, the method can start with some event, such as power-up or start-up of the host device, user-induced exit from a hibernate or sleep mode due to physical stimulus or arrival of an external phone call, or automatic exit. Many alternatives are possible.

[0139] By default, the USB system can have control over the USB-C interface. At step 1101, the USB controller can thus be configured by the processor in overall control of the host device to monitor the CC pins (A5 and B5) to monitor attachment of a plug, e.g. by monitoring the voltage. As a downstream facing port, the USB controller can look for a characteristic impedance Rd or Ra (where Rd and Ra are defined in the USB Type-C specification and Rd > Ra) connected to the CC pins. If or when a connection is determined to be present, the combination of impedances present at the CC pins can be used to determine the connection type and orientation. Thus, for example, impedance Rd connected to one CC pin and the other CC pin open circuited defines an upstream facing port UFP being attached and provides orientation by which CC is connected to Rd. Impedance Rd at one pin and impedance Ra at the other pin implies a power supply cable attached the UFP, while impedance Ra at one pin and the other pin open circuited implies a power supply cable without a UFP. Impedance Rd at both pins allows operation in debug mode.

[0140] However, as described above, if both pins A5 and B5 are connected to digital ground through an impedance less than the value Ra (where Ra is equal to 1.2 kilo-ohms), the "audio accessory adapter mode" can be initiated. Thus, at step 1102, it can be determined whether both CC pins have an impedance below a certain value or threshold, i.e. Ra.

[0141] If not (i.e. if at least one of the CC pins is connected to an impedance greater than Raor is an open circuit), the values of both impedances relative to Raand Rdare detected and analyzed in step 1103, and the system enters the appropriate mode, e.g. for a power cable, attached UFP, or debugging mode in step 1104. Thus, it will be appreciated that if a suitable peripheral or hub is connected, the host device can operate in a USB mode for digital data transfer via the Type-C receptacle. In this USB mode, the USB physical controller 310 can activate its outputs to establish a pair of signal paths to pins A6 and A7 or pins B6 and B7 on the receptacle or other host device connector to provide a differential digital data path to the accessory. In step 1105, the USB controller continues to monitor for detachment of the plug, in which event it can disable the USB physical interface and return to step 1101 to detect any subsequent re-attachment.

[0142] However, if it is determined in step 1102 that the impedances attached to the CC pins are all below a certain value or threshold (i.e. Ra), the host device can enter an audio accessory adapter mode. This changes the use of at least some of the four central pins A6, A7, B6 and B7 to carry analog signals, e.g. to and / or from the audio codec 401. In the audio accessory adapter operating mode, a suitable signal path to and / or from these pins can be enabled by an audio path controller, which can be implemented at least in part by the audio codec 401.

[0143] Note that when the USB supervisory system has detected attachment or removal of a USB plug, it can signal the audio codec 401 of the attachment of the USB plug or, in particular, the removal of the USB plug. (Additionally or alternatively, in the case of a USB plug being connected to an adapter containing a jack socket, the detection can rely on a suitable jack plug being inserted into the adapter jack socket, so the USB supervisory circuitry can signal the attachment or removal of the jack plug from the adapter jack socket.

[0144] However, in order to better suppress the audible pop and click on detachment, it can be better for the codec to directly sense this, rather than for the USB supervisory system to detect the removal of the plug. This avoids any processing latency involved in the sensing circuitry in the USB chip sensing that it is disconnected and communicating with the codec, e.g. via a suitable GPIO (general purpose input output) pin. It will be appreciated that many existing codecs already include a jack detection module, JACKDET, to sense the presence of a 3.5mm jack using a contact of a mechanical switch to ground. Thus, as Figure 3 、 Figure 5 andFigure 10 As exemplified in the middle, the codec 401 can include a jack detection module JACKDET 470 connected to the CC pins A5 and / or B5 of the receptacle 404. Upon detecting that an analog audio peripheral 300, 500, 600 is connected, the USB physical controller 310 can activate this module in step 1110 (note that the term "jack detection" as used in this document shall include detection of USB Type-C plug insertion into and / or removal from the receptacle).

[0145] The jack detection module can continue to monitor the presence of an impedance from the CC pins to ground, and if this impedance disappears, for example due to removal of the USB plug, then any other active codec outputs can be deactivated in step 1112, and other actions necessary to reset the interface can be performed in step 1113, for example informing the USB controller and / or any total host device controller. The USB controller can be configured to operate as in step 1101 to monitor for any re-attachment.

[0146] Once it has been identified in step 1102 that an analog peripheral is connected, the discovery controller circuitry in the audio codec 401 can perform further tests to determine the connection configuration for the attached peripheral. As described above, this can involve determining the type of load, if any, connected to at least some of the contacts of the receptacle. Based on the allowed device configurations and the two possible docking orientations of the plug in the receptacle, there can be a limited set of possible connection configurations. The method can involve determining the load type for a particular number of contacts until the discovery module can correctly identify the connection configuration.

[0147] In step 1121, the discovery module can determine whether any of the receptacle pins A8 and B8 are connected to one common ground loop of the accessory, and if so, which of the two pins is connected to this ground loop and which can be connected to another component, such as a voice microphone or a button resistor bank.

[0148] In step 1122 (which can occur after, before, or in parallel with step 1121), the discovery module can attempt to determine whether a characteristic impedance Rch is connected between the host device connector's pin A8 or B8 and the accessory's digital ground connection. Based on a predefined convention, for example that this impedance is connected to the accessory connector's pin A8, the polarity of the relative orientation of the host connector and the accessory connector can be inferred depending on whether this impedance is connected to the host connector's pin A8 or B8.

[0149] The discovery module can also determine the value of the impedance of the connection and can thus determine the type or model of the accessory according to some predefined mapping of the range of impedance values by the accessory.

[0150] For a particular device, the characteristic impedances Rch 312 can each take a particular value associated with that particular type of peripheral device (and a particular set of signal paths between the codec 401 and the connector 404) in, for example, a lookup table.

[0151] For example, a first value (e.g. 10 kOhms) or a range of impedance values centered on that first value for the characteristic impedance Rch can be associated with a regular set of earphones having left and right speakers and one voice microphone; a second value (e.g. 20 kOhms) for the characteristic impedance Rch can be associated with a set of earphones having left and right speakers, one voice microphone and one or more noise cancelling microphones; a third value (e.g. 30 kOhms) for the characteristic impedance Rch can be associated with a set of balanced earphones having left and right speakers (each driven by two outputs) and one voice microphone; other values of impedance can be associated with different types of devices including a processor and possibly requiring different connections to the codec 401.

[0152] The discovery module is thus able to determine the type of peripheral device connected to the host device 400 by measuring the value of the characteristic impedance Rch. The discovery module can consult a lookup table (which can be located in a memory stored on the codec 401, or in some other memory provided in the device 400) to determine the type of device, or more specifically the necessary configuration of components of the codec 401, which is associated with the measured impedance value. This information, together with the known orientation of the socket connector 404 relative to the plug connector 302, 502, 602 allows the codec to be configured to drive or monitor the appropriate pins of the socket connector 404.

[0153] Assuming that the accessory that has been attached is of the expected type or configuration, the discovery controller will now determine the relative orientation of the socket or host device connector 404 relative to the plug or accessory connector 302, 502, 602 etc. via steps 1121 and / or 1122.

[0154] In step 1123, the discovery module can proceed to further measure the impedance between each of the host device connector pins, which is necessary for the discovery controller to determine which of any other possible connection arrangement variants the accessory comprises in step 1124.

[0155] Thus, in step 1125, the signal paths to the A6, A7, B7, and B8 pins are configured based on the known orientation of the connector 404 and the known type of peripheral 300, 500, 600. For example, one of the pins A8 and B8 that has been determined to be connected (504) to the common ground return from the accessory can be connected to the analog ground of the host device. The microphone bias coupled to the other of the pins A8 and B8 can be activated to provide bias for the voice microphone determined to be connected to this other pin.

[0156] Note that some components can not be immediately fully activated, but rather merely placed in a state where they will be activated later. For example, the earphone driver amplifiers can not be powered up in some cases, or their outputs can be pulled to ground until there is a signal that needs to be driven through the speakers.

[0157] As mentioned above, once the attached headset is activated, the user can be able to declare his commands in some embodiments by altering the impedance across the microphone pins with a pushbutton switch or the like. Thus, in step 1130, the resistance across these pins is monitored, and any resistance change interrupts. In addition, other configurations of the codec can be requested by the user or system in step 1131. The user can request a variety of codec functions via other inputs, such as keyboard input or touch screen input or even speech recognition secondary input. In addition, the system can request other configurations of the codec due to other system stimuli, such as an incoming voice telephone call. All of these inputs can be received, arbitrated if necessary, and then responded to in step 1132 by appropriately configuring the signal paths in the codec in response to all of these inputs.

[0158] It should be understood that the connections described above are by way of example only, and other possible connections between the audio components of the peripheral or accessory device and the pins of the Type-C connector are possible. However, in general, the pins A5 and B5 should be reserved as CC pins, and preferably any analog data can be transmitted via contacts A6-A8 and / or B6-B8 and especially via contacts A6, A7, B6, and B7.

[0159] Note that according to embodiments of the application, the steps of enabling the signal paths between the pins and the components of the codec 401 can include physically switching the paths between the components as needed, rather than activating and deactivating the components within the codec 401.

[0160] In addition, it should be understood that Figure 3Analog connections from a host device to stereo loudspeakers and incoming analog signals from multiple microphones to the host device are exemplified, at least some of the incoming analog signals can be used for noise cancellation. However, it will be appreciated that other combinations of microphones and / or loudspeakers can be enabled, for example the peripheral device can be a headset without a voice microphone but with left and right noise cancellation microphones. It will further be appreciated that the idea can also be applied to other combinations of analog sources and sinks and signals flowing in either direction.

[0161] For example, the peripheral device can be a speakerphone accessory with for example 5 microphones, where analog connections to the microphones are enabled via the ground loops on plug pins A6, A7, A8, B6 and B7 and B8.

[0162] In some embodiments, the peripheral device can comprise at least some circuitry that in use is powered by the voltage provided on the voltage bus pins of the Type-C connector. The Type-C specification identifies pins A9 and B9 as voltage bus pins V BUS for power delivery. Thus, in some embodiments, the host device can provide suitable power on this V BUS connection, powering the chips in the peripheral device.

[0163] As mentioned above, embodiments of the application thus provide methods and apparatus for connecting a peripheral device to a host device via a universal or multi-purpose connector, such as a USB Type-C connector. Embodiments allow an analog data channel to be established so that audio components of the peripheral device can be operated through an analog drive / read signal path between the host device and the peripheral device, and provide more data channels than conventional methods.

[0164] Embodiments allow the use of an audio accessory device with at least four independent audio input or output signal paths via separate contacts of a first connector, which can comprise a connector arranged in a rotationally symmetric configuration, for example a connector compatible with a USB Type-C connector. At least a plurality of the signal paths can be used to carry analog audio signals.

[0165] As mentioned, one particular application is for enabling an analog data channel for at least stereo loudspeakers in a balanced configuration. The application can also enable a channel for reading data from a voice microphone.

[0166] Figure 12A host device 400 is exemplified, which can for example be a mobile phone or mobile computing device such as a laptop or tablet computer. The mobile device can have a connector for connecting to a peripheral or accessory device and the connector can be a Type-C receptacle 404. In use, the host device can be connected to an accessory 300 by connecting the Type-C plug 302 of the accessory to the receptacle 404 of the host device. The plug 302 can be connected to the rest of the accessory 300 via a connection 303 which can comprise a fixed cable.

[0167] The Type-C receptacle can be coupled to USB interface circuitry 701 which can include a high speed USB 3.1 interface to other pins of the USB Type-C connector, for example including A2, A3, A4 or A9, A10, A11. Other pins of the receptacle can be coupled to the USB interface circuitry 701 and to the audio codec 401, for example pins A6, A7, A8.

[0168] The host device includes data controller circuitry to control discovery and configuration of signal paths from the receptacle 404 to a signal source or signal sink which can reside in the wireless communication interface 704 or in one area of local storage or memory 702 or in the application processor 703. As discussed with reference to Figure 4 The data controller can be considered to include a discovery controller and a path controller. This discovery controller and path controller circuitry can each be partially or wholly incorporated in one or more of the USB interface 701, the audio codec 401, the application processor 703. For example, circuitry for detecting standard USB operation can be incorporated in the USB interface circuitry 701, but once the audio adapter accessory mode is detected, control can be handed over substantially to control circuitry within the audio codec 401.

[0169] The data controller circuitry can be specifically designed or hardwired to perform the appropriate functions, or can at least partially comprise general purpose programmable circuitry which can be operated according to code or instructions stored in a portion of the local memory 702 which can comprise non-volatile memory elements.

[0170] The audio codec 401 can transmit analog audio data to the accessory 300 for playback via the speaker of the accessory 300. The audio data can comprise audio data from a media file stored in the memory 702, which can be received from this memory directly or via the application processor 703. In some instances, the audio data can be generated by the application processor 703 or by the audio codec under instructions from the application processor. The audio data can be audio data received via a communications interface, such as the antenna 704 for wireless communications.

[0171] In addition, the audio codec 401 can receive audio data from the accessory 300. This data can for example be analog voice data from a voice microphone, which is to be transmitted via the antenna 704, which is to be stored in a media file in the memory 702 or which is to be processed for controlling the application processor 703. The audio codec 401 can also receive audio data from a noise cancelling microphone of the accessory 300. This data can also be conveyed via an analog data path. A noise cancelling module 705 of the codec 401 can determine an appropriate noise cancelling signal and modulate the outgoing analog speaker data accordingly.

[0172] Thus, the skilled person will appreciate that some aspects of the apparatus and methods described above, such as the discovery and configuration methods, can be embodied as processor control code, for example on a non-transitory carrier medium such as a disk, CD-ROM or DVD-ROM, programmed memory such as read-only memory (Firmware), or on a data carrier such as an optical or electrical signal carrier. For many applications embodiments of the application will be implemented on a DSP (Digital Signal Processor), ASIC (Application-Specific Integrated Circuit) or FPGA (Field Programmable Gate Array). Thus the code can comprise conventional programming code or microcode or, for example code for setting up or controlling an ASIC or FPGA. The code can also comprise code for dynamically configuring a reconfigurable apparatus such as, for example, a field programmable gate array. Similarly the code can comprise code for TM configuring reconfigurable apparatuses such as, for example, reprogrammable logic gates. The code can be distributed as object code or, as source code, such as, for example, in JavaScript or ECMAScript. Those skilled in the art will further appreciate that code for the application can be distributed over several coupled components in communication with one another and thus a single functional unit. Where appropriate, the embodiments can also be implemented using code stored in a storage medium that can be read by a machine, e.g., a computer. The code may, for example, cause a machine to perform (or avoid performing) one or more embodiments of the application. The code can comprise, for example, ASCII or Unicode characters. Note, further, that the machine readable medium can comprise a wireless signal.

[0173] Note that as used herein, the term "module" shall be taken to refer to a functional unit or block of functionality that can be implemented at least in part by a dedicated hardware component such as custom circuitry and / or at least in part by a suitable code running on one or more software processors or suitable code running on a suitable general purpose processor or the like. A module can itself comprise other modules or functional units. A module can be provided by multiple components or sub-modules that do not need to cooperate on the same site and can be disposed on different integrated circuits and / or run on different processors. For example, the above-mentioned microphone bias block, microphone detection block and earpiece detection block can share components.

[0174] Embodiments can be implemented in host devices, especially portable and / or battery powered host devices such as mobile telephones, audio players, video players, PDAs, mobile computing platforms such as e.g. laptop computers or tablet computers and / or e.g. gaming devices. Embodiments of the present application can also be implemented in whole or in part in accessories that can be attached to a host device, e.g. in active speakers or headphones or the like. Especially in more complex devices, there can be more than one USB Type-C connector or similar connector according to aspects of the present application and associated signal paths and controls.

[0175] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim "a" or "an" shall not exclude the presence of a plurality of these elements, and a single unit can fulfil the functions of several units, just as a singular can be embodied by a plurality. Any reference signs in the claims should not be construed as limiting the scope of the claims. Terms such as "amplify" or "gain" include the possibility of applying a scale factor to a signal that is less than 1.

Claims

1. A data controller for controlling data transmission between a host device and a peripheral device via a connector of the host device, the connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than 1, the data controller comprising: A discovery module operable to detect the presence of one or more characteristic impedances on the contacts of the connector; as well as A path controller is provided for enabling a signal path between the circuitry of the host device and the contacts of the connector. The path controller is operable in at least one first mode and multiple second modes to enable the signal path between the circuitry of the host device and the contacts of the connector. The detection module is operable to detect the presence of a first characteristic impedance on any one of the first and second contacts of the connector and a second characteristic impedance on any one of the third and fourth contacts of the connector, wherein the first, second, third, and fourth contacts are different from each other. The path controller is configured to select either the first mode or the plurality of second modes based on the detection of the first characteristic impedance, and the path controller is configured to select one of the plurality of second modes based on the value of the second characteristic impedance after selecting the plurality of second modes.

2. The data controller of claim 1, wherein the first mode is for digital data transmission, and wherein the plurality of second modes includes a mode for transmitting analog data.

3. The data controller according to claim 1 or 2, wherein the first contact and the second contact are positioned at a rotationally symmetrical position on the connector.

4. The data controller of claim 1 or 2, wherein the discovery module is operable to detect a first characteristic impedance on each of the first and second contacts, and wherein the path controller is configured to select the first mode or the plurality of second modes based on the detection of the first characteristic impedance on both the first and second contacts.

5. The data controller of claim 1 or 2, wherein the path controller is operable to access a lookup table storing a plurality of impedance values ​​for each of the plurality of second modes, and wherein the path controller is configured to select one of the second modes based on the value of the second characteristic impedance.

6. The data controller according to claim 1 or 2, wherein each of the plurality of second modes corresponds to a different configuration of the signal path between the circuitry of the host device and the contacts of the connector.

7. The data controller of claim 6, wherein each configuration of the signal path is suitable for a different type of peripheral device.

8. The data controller of claim 7, wherein in at least one of the rotational orientations of the connector relative to the peripheral device's connector, each configuration of the signal path is suitable for a different type of peripheral device.

9. The data controller of claim 7, wherein the type of peripheral device includes one or more of the following: headsets, headsets including a voice microphone, headsets including a voice microphone and one or more noise-cancelling microphones, line outputs, balanced headsets, and devices requiring a digital data connection to the host device.

10. The data controller of claim 6, wherein at least one of the configurations includes corresponding enabled signal paths between a first output amplifier and a second output amplifier of the host device and a fifth and a sixth contact of the connector, the first output amplifier and the second output amplifier generating audio output signals of equal and opposite magnitudes.

11. The data controller of claim 1 or 2, wherein the discovery module is configured to determine which of at least two predetermined additional contacts of the connector is a ground contact connected to a ground loop for the peripheral device, and wherein the path controller is further configured to select one of the second modes based on which of the at least two predetermined additional contacts of the connector is a ground contact connected to a ground loop for the peripheral device.

12. The data controller of claim 11, wherein the at least two predetermined additional contacts are positioned at a rotationally symmetrical position on the connector.

13. The data controller according to claim 1 or 2, wherein the connector has n-fold rotational symmetry about an axis that is generally parallel to the insertion direction of the connector and the corresponding connector of the peripheral device.

14. The data controller of claim 1 or 2, wherein the connector is a USB Type C connector.

15. A peripheral electronic device for connection to a host electronic device via its connector having a plurality of contacts arranged in a manner having n-fold rotational symmetry, wherein n is an integer greater than 1, the peripheral electronic device comprising: A pair of first characteristic impedances are coupled to the first and second contacts of the connector, and detection of the pair of first characteristic impedances causes the host electronic device to be placed in a first mode; One or more operating components, coupled to at least a third contact of the connector, are configured to transmit data to and receive data from the host electronic device; as well as A second characteristic impedance, separate from the one or more operating components, is directly coupled to one of a pair of rotationally symmetric contacts of the connector, enabling the host electronics to determine the orientation of the connector.

16. The peripheral electronic device of claim 15, wherein the second characteristic impedance has an impedance value indicating the device type of the peripheral electronic device.

17. The peripheral electronic device according to claim 15 or 16, wherein the second characteristic impedance is a resistor.

18. The peripheral electronic device of claim 15 or 16, wherein the pair of rotationally symmetric contacts includes the third contact and the fourth contact, wherein the second characteristic impedance is directly coupled to the fourth contact, and wherein the second characteristic impedance is coupled to the third contact via an operating component of the one or more operating components.

19. The peripheral electronic device of claim 15, wherein the one or more operating components include a speaker coupled to a third and a fourth contact of the connector, and wherein the speaker is not coupled to any other contact of the connector.

20. The peripheral electronic device of claim 15 or 16, wherein the one or more operating components include one or more of the following: a speaker; a microphone; and a processing circuit system.

21. An electronic device, comprising: A connector comprises multiple contacts having n-fold rotational symmetry, where n is an integer greater than 1; as well as The data controller according to any one of claims 1 to 14.

22. An apparatus associated with a connector for data transmission between a host device and a peripheral device, comprising: An audio codec used to provide audio signals to peripheral devices; A path controller is configured to enable a signal path between contacts of a connector of an audio codec and a host device, the connector comprising a plurality of contacts having n-fold rotational symmetry, where n is an integer greater than 1, the path controller being operable to enable separate signal paths between a first amplifier of the audio codec and at least one first contact of the connector, and between a second amplifier of the audio codec and at least one second contact of the connector, the at least one first contact and the at least one second contact being positioned at rotationally symmetric locations on the connector; as well as A discovery module is operable to detect the presence of characteristic impedance on at least one contact of the connector, thereby determining the orientation of the peripheral device's connector relative to the host device's connector. The audio codec is operable in a first operating mode to provide an audio signal via the first amplifier, and is operable in a second operating mode to provide an audio signal via the second amplifier. The path controller is operable to select between the first operating mode and the second operating mode based on the orientation of the connector.

23. The apparatus of claim 22, wherein in the first operating mode, the second amplifier is deactivated, and wherein in the second operating mode, the first amplifier is deactivated.

24. The apparatus of claim 22 or 23, wherein the first amplifier is permanently coupled to the first contact, and wherein the second amplifier is permanently coupled to the second contact.

25. The apparatus of claim 24, wherein the audio codec includes one or more first additional electronic components permanently coupled to the first contact and one or more second additional electronic components permanently coupled to the second contact, wherein in the first operating mode, the one or more first additional electronic components are deactivated, and wherein in the second operating mode, the one or more second additional electronic components are deactivated.

26. The apparatus of claim 22 or 23, wherein the discovery module is configured to determine which of at least two predetermined additional contacts of the connector is a ground contact connected to a ground loop for the peripheral device, and wherein the path controller is further configured to select between a first operating mode and a second operating mode based on which of the at least two predetermined additional contacts of the connector is a ground contact connected to a ground loop for the peripheral device.

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