PATENT DOCUMENT

Publication Number: US-9436761-B2
Application Number: US-201313841628-A
Country: US
Kind Code: B2

Title: Data communications via limited length audio jack

Abstract:
Methods, systems, and apparatus for selectively communicating data and audio over a limited-size audio plug. A host device determines whether an audio accessory or a data communicating accessory is plugged therein via a signal, or lack thereof, communicated to the host device via the audio plug of the accessory. The host device then either communicates audio or data over the audio plug contacts that are typically used only for audio communication based on whether its connected to an audio accessory or data communicating accessory. An audio plug may also include a split-ring contact where multiple, independent contacts are formed in place of a single tip, ring, or sleeve contact. The split-ring contact may be used for communicating audio and/or data.

Claims:
What is claimed is: 
     
       1. A method for selectively communicating audio and data over a plug connector, comprising:
 detecting, at a receptacle connector of an electronic device including a plurality of receptacle contacts, insertion of a plug connector into the receptacle connector, the plug connector including an insertion element coupled to a base, the insertion element including a plurality of plug contacts arranged linearly between the base and a tip of the insertion element, the plurality of plug contacts including: a tip contact arranged at the tip of the insertion element, and a ring contact arranged between the tip contact and the base; 
 determining whether a signal having a predetermined voltage is communicated to the electronic device via one or more of a first contact of the plurality of receptacle contacts and a second contact of the plurality of receptacle contacts, the first contact being arranged to electrically contact the tip contact of the plug connector upon insertion of the plug connector into the receptacle connector, the second contact being arranged to electrically contact the ring contact upon insertion of the plug connector into the receptacle connector; and 
 selectively communicating one of an audio signal and a bi-directional handshake data signal via at least one of the first contact or the second contact based on whether it is determined that the signal having the predetermined voltage is communicated to the electronic device. 
 
     
     
       2. The method of  claim 1 , further comprising:
 communicating the audio signal via the first contact and the second contact when it is determined that the signal having the predetermined voltage is not communicated to the electronic device via one or more of the first contact and the second contact. 
 
     
     
       3. The method of  claim 1 , further comprising:
 prior to detecting insertion of a plug connector into the receptacle connector:
 disabling an electrical connection between audio output circuitry of the electronic device and the first contact and the second contact; and 
 enabling an electrical connection between data communication circuitry of the electronic device and the first contact and the second contact. 
 
 
     
     
       4. The method of  claim 3 , further comprising:
 upon determining that the signal having the predetermined voltage was not communicated to the electronic device via one or more of the first contact and the second data:
 disabling the electrical connection between data communication circuitry of the electronic device and the first contact and the second contact; 
 enabling the electrical connection between audio output circuitry of the electronic device and the first contact and the second contact; and 
 communicating the audio signal via the first contact and the second contact. 
 
 
     
     
       5. The method of  claim 4 , further comprising:
 determining whether the plug connector has been removed from the receptacle connector; and 
 upon determining that the plug connector has been removed from the receptacle connector:
 disabling an electrical connection between audio output circuitry of the electronic device and the first contact and the second contact; and 
 enabling an electrical connection between data communication circuitry of the electronic device and the first contact and the second contact. 
 
 
     
     
       6. The method of  claim 1 , wherein determining whether a signal having a predetermined voltage is communicated to the electronic device via one or more of a first contact and a second contact includes determining whether there is a voltage differential between a voltage at a third contact of the receptacle contacts corresponding to an electrical ground and one of the first contact and the second contact. 
     
     
       7. An electronic device comprising:
 a receptacle connector capable of detecting an insertion of a plug connector into the receptacle connector and including a plurality of receptacle contacts, the plug connector including an insertion element coupled to a base, the insertion element including a plurality of plug contacts arranged linearly between the base and a tip of the insertion element, the plurality of plug contacts including: a tip contact arranged at the tip of the insertion element, and a ring contact arranged between the tip contact and the base; 
 communication circuitry coupled to the receptacle connector and operable to:
 determine whether a signal having a predetermined voltage is communicated to the electronic device via one or more of a first contact of the plurality of receptacle contacts and a second contact of the plurality of receptacle contacts, the first contact being arranged to electrically contact the tip contact of the plug connector upon insertion of the plug connector into the receptacle connector, the second contact being arranged to electrically contact the ring contact upon insertion of the plug connector into the receptacle connector; and 
 selectively communicate one of an audio signal and a bi-directional handshake data signal via at least one of the first contact or the second contact based on whether it is determined that the signal having the predetermined voltage is communicated to the electronic device. 
 
 
     
     
       8. The electronic device of  claim 7 , wherein the communication circuitry is operable to:
 communicate the audio signal via the first contact and the second contact when it is determined that the signal having the predetermined voltage is not communicated to the electronic device via one or more of the first contact and the second contact. 
 
     
     
       9. The electronic device of  claim 7 , wherein the communication circuitry is operable to:
 prior to detecting insertion of a plug connector into the receptacle connector:
 disable an electrical connection between audio output circuitry of the electronic device and the first contact and the second contact; and 
 enable an electrical connection between data communication circuitry of the electronic device and the first contact and the second contact. 
 
 
     
     
       10. The electronic device of  claim 9 , wherein the communication circuitry is operable to:
 upon determining that the signal having the predetermined voltage was not communicated to the electronic device via one or more of the first contact and the second data:
 disable the electrical connection between data communication circuitry of the electronic device and the first contact and the second contact; 
 enable the electrical connection between audio output circuitry of the electronic device and the first contact and the second contact; and 
 communicate the audio signal via the first contact and the second contact. 
 
 
     
     
       11. The electronic device of  claim 10 , wherein the communication circuitry is operable to determine whether the plug connector has been removed from the receptacle connector; and
 upon determining that the plug connector has been removed from the receptacle connector (1) disable an electrical connection between audio output circuitry of the electronic device and the first contact and the second contact, and (2) enable an electrical connection between data communication circuitry of the electronic device and the first contact and the second contact. 
 
     
     
       12. The electronic device of  claim 7 , wherein the communication circuitry is operable to:
 determine whether there is a voltage differential between a voltage at a third contact of the receptacle contacts corresponding to an electrical ground and one of the first contact and the second contact when determining whether a signal having a predetermined voltage is communicated to the electronic device via one or more of a first contact and a second contact.

Description:
BACKGROUND 
     Many electronic devices such as cellular phones, tablet computers, and the like have numerous input/output (I/O) interfaces that allow connectivity with other devices using one or more structural and communication protocol standards or, in some cases, proprietary standards. Such I/O interfaces make debugging the electronic devices by software engineers a fairly seameless task as the debugging tool can interface with the electronic devices using one or more of these common I/O interfaces, such RS-232, USB, etc. 
     Some electronic devices, however, have a limited number and type of I/O interfaces. A good example is portable audio players in which only an audio receptacle for receiving an audio plug (also known as an audio jack, stereo plug, mini-stereo headphone jack, microphone jack, etc.) may be provided. In these types of electronic devices debugging becomes much more challenging as the audio receptacle is typically designed to only carry audio signals (audio output from the device and, in some cases, microphone input). Debugging using a wireless communication technique is possible but also fraught with difficulties, including challenges arising from when the problems with the electronic devices arise from or interfere with the devices wireless communication circuitry, and challenges arising from wirelessly communicating with many devices arranged in close proximity to one another on an assembly line. 
     Some techniques for communicating data over an audio plug are known. These techniques typically call for data to be communicated from the electronic device via the audio output channels of the audio receptacle, and for data to be communicated to the electronic device via the microphone channel of the audio receptacle. That is, audio plugs include TS (tip-sleeve) connectors, TRS (tip-ring-sleeve) connectors, and TRRS (tip-ring-ring-sleeve) connectors, where ‘tip’ refers to an electrical contact being arranged at the tip of the audio plug, ‘ring’ refers to a ring contact being arranged next to the tip contact, and ‘sleeve’ refers to a contact being arranged at an end of the connector opposite the tip. For stereo audio, at least a TRS is generally required, as the tip and ring contacts are used for the left and right audio channels, respectively, and the sleeve contact is used as ground. To add a microphone channel, a TRRS connector is generally required, where the second ring contact is used for the microphone channel. 
     Accordingly, TRRS audio plugs may generally be used to communicate data via the microphone channel and one of the audio channels. However, there are continuing efforts to reduce the size of electronic devices, especially devices intended to be ‘portable’, and thus continuing efforts to reduce the size of the I/O interfaces included therewith. Since industry standards have evolved that effectively define the minimum lengths/spacing of tip, ring, and sleeve contacts of an audio plug, it may be extremely difficult and/or costly to incorporate a receptacle sized to receive a TRRS audio plug where the receptacle is both (a) compatible with the industry standards defined for the TRRS audio plug and (b) small enough to be effectively integrated into reduced size electronic devices. Thus, challenges arise when attempting to communicate data to and from an electronic device having a reduced-size audio plug receptacle as there is often insufficient space for the microphone contact that enables data to be communicated to the electronic device. 
     SUMMARY 
     Embodiments of the present invention are generally directed to host devices, accessories, and audio plugs. Some particular embodiments are directed to selectively communicating audio and data over a plug connector, communicating audio and/or data over a connector having a split-ring contact, and audio plugs including split-ring contacts. 
     In accordance with some of the methods described herein, an electronic device may be operable to selectively communicate audio and data over a plug connector to an accessory. This may be done by the electronic device detecting, at a receptacle connector of the electronic device including a plurality of receptacle contacts, insertion of a plug connector into the receptacle connector. The plug connector includes an insertion element coupled to a base, and the insertion element includes a plurality of plug contacts arranged linearly between the base and a tip of the insertion element. The plurality of plug contacts include a tip contact arranged at the tip of the insertion element, and a ring contact arranged between the tip contact and the base. The electronic device may then determine whether a signal is communicated to the electronic device via one or more of a first contact of the plurality of receptacle contacts and a second contact of the plurality of receptacle contacts. The first contact is arranged to electrically contact the tip contact of the plug connector upon insertion of the plug connector into the receptacle connector, and the second contact is arranged to electrically contact the ring contact upon insertion of the plug connector into the receptacle connector. The electronic device may then selectively communicate one of an audio signal or a data signal via at least one of the first contact or the second contact based on whether it is determined that a signal is communicated to the electronic device via one or more of the first contact and the second contact. 
     In accordance with other methods described herein, an electronic device may be operable to selectively communicate audio and data over a plug connector having a split-ring contact. This may be done by the electronic device detecting, at a receptacle connector of the electronic device including a plurality of receptacle contacts, insertion of a plug connector into the receptacle connector. The plug connector includes an insertion element coupled to a base, and the insertion element includes a plurality of plug contacts arranged linearly between the base and a tip of the insertion element. The plurality of plug contacts include a split-ring contact, where the split ring contact includes a plurality of contacts that partially circumscribe an axis extending linearly from the base to the tip of the insertion element. The contacts of the split ring are electrically insulated from one another. The electronic device then determines whether a signal is communicated to the electronic device via one or more of the plurality of receptacle contacts, and then selectively communicates one of an audio signal and a data signal via at least one of the plurality of receptacle contacts. Communicating the data signal includes communicating the data signal to at least one of the receptacle contacts that electrically contacts at least one of the plurality of contacts forming the split ring contact when the plug connector is fully inserted into the receptacle connector. 
     In addition to the methods of operating electronic devices described herein, embodiments are also directed to electronic devices. An electronic device according to one embodiment may include a plug connector including a base and an insertion element. The insertion element is coupled to and extends linearly from the base, and includes a plurality of plug contacts arranged linearly between the base and a tip of the insertion element. The plurality of plug contacts include a tip contact arranged at the tip of the insertion element, and a ring contact arranged between the tip contact and the base. The electronic device may also include communication circuitry coupled to the plug connector and operable to perform a variety of operations. For example, the communication circuitry may be operable to output a signal over at least one of the tip contact and the ring contact, determine whether a response to the signal is received over at least one of the tip contact and the ring contact, and establish data communication over the tip contact and the ring contact when it is determined that a response to the signal is received over at least one of the tip contact and the ring contact. 
     An electronic device according to another embodiment may include a plug connector including a base and an insertion element. The insertion element is coupled to and extends linearly from the base, and includes a plurality of plug contacts arranged linearly between the base and a tip of the insertion element. The plurality of plug contacts includes a split-ring contact. The split ring contact includes a plurality of contacts that partially circumscribe an axis extending linearly from the base to the tip of the insertion element, where the contacts of the split ring are electrically insulated from one another. The electronic device may also include communication circuitry coupled to the plug connector. The communication circuitry may be operable to perform a variety of operations. For example, the communication circuitry may be operable to output a signal over at least one of the plug contacts, determine whether a response to the signal is received, and establish data communication over at least one of the contacts forming the split ring contact when it is determined that a response to the signal is received over at least one of the tip contact and the ring contact. 
     In addition to the electronic devices and methods of operating electronic devices described herein, embodiments are also directed to audio plug connectors having one or more split-ring contacts. Specifically, at least one embodiment is directed to a plug connector including a base operable to support the plug connector for insertion into and removal from a receptacle connector. The plug connector may also include an insertion element extending linearly from the base. The insertion element includes a plurality of electrical contacts each extending linearly from the base. At least two of the electrical contacts have portions that are located at identical distances from the base, where the at least two electrical contacts are electrically isolated from one another. The plug connector may further include a plurality of conductive elements disposed within the insertion element. The conductive elements are electrically coupled to at least some of the electrical contacts of the insertion element so as to communicate signals between the electrical contacts and one or more electronic devices coupled to the plug connector. 
     For a fuller understanding of the nature and advantages of embodiments of the present invention, reference should be made to the ensuing detailed description and accompanying drawings. Other aspects, objects and advantages of the invention will be apparent from the drawings and detailed description that follows. However, the scope of the invention will be fully apparent from the recitations of the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a system for selectively establishing data communication or audio communication over an audio plug according to an embodiment. 
         FIG. 2A  is a schematic diagram of plug detection circuitry according to an embodiment. 
         FIG. 2B  is a schematic diagram of audio output circuitry according to an embodiment. 
         FIG. 2C  is a schematic diagram of data communication circuitry according to an embodiment. 
         FIG. 3  illustrates a process of a host device for selectively establishing data communication or audio communication over an audio plug according to an embodiment. 
         FIG. 4  illustrates a process of an accessory for establishing data communication over an audio plug according to an embodiment. 
         FIG. 5A  illustrates a simplified split-ring plug connector according to a first embodiment. 
         FIG. 5B  illustrates a cross-sectional view of the split ring connector of  FIG. 5A  through plane A-A. 
         FIG. 6A  illustrates a simplified split-ring plug connector according to a second embodiment. 
         FIG. 6B  illustrates a cross-sectional view of the split ring connector of  FIG. 6A  through plane B-B. 
         FIG. 7A  illustrates a simplified split-ring plug connector according to a third embodiment. 
         FIG. 7B  illustrates a cross-sectional view of the split ring connector of  FIG. 7A  through plane C-C. 
         FIG. 8A  illustrates an isometric view a split-ring plug connector according to an embodiment. 
         FIG. 8B  illustrates a cross-sectional view of the split-ring plug connector of  FIG. 8A  through a plane extending along the length of and through the center of the plug connector. 
         FIG. 8C  illustrates a cross-sectional view of the split-ring plug connector of  FIG. 8A  through a plane extending perpendicular to the length of connector (i.e., through line E-E). 
         FIG. 9  illustrates a system for establishing data communication and/or audio communication over a split-ring audio plug according to an embodiment. 
         FIG. 10  illustrates a process of a host device for selectively establishing data communication or audio communication over an audio plug having a split-ring contact according to an embodiment. 
         FIG. 11  illustrates a process of an accessory for selectively establishing data communication over an audio plug having a split-ring contact according to an embodiment. 
         FIG. 12  illustrates a cross-sectional view of a split-ring plug connector similar to that described with reference to  FIGS. 5A, 5B, and 8A through 8C , and includes a first contact arranged opposite a second contact whereby those contacts are electrically isolated from one another via insulation elements. 
         FIG. 13A  illustrates a cross-sectional view of a receptacle having redundant receptacle contacts according to a first embodiment. 
         FIG. 13B  illustrates a cross-sectional view of a receptacle having redundant receptacle contacts according to a second embodiment. 
         FIG. 13C  illustrates a cross-sectional view of a receptacle having redundant receptacle contacts according to a third embodiment. 
         FIG. 14  illustrates a cross-sectional view of a split-ring plug connector similar to that described with reference to  FIGS. 6A and 6B , and includes a first contact, a second contact, and a third contact, electrically insulated from one another via first insulation element, second insulation element, and third insulation element. 
         FIG. 15A  illustrates a cross-sectional view of a receptacle having redundant receptacle contacts according to a fourth embodiment. 
         FIG. 15B  illustrates a cross-sectional view of a receptacle having redundant receptacle contacts according to a fifth embodiment. 
         FIG. 15C  illustrates a cross-sectional view of a receptacle having redundant receptacle contacts according to a sixth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments for communicating data and/or audio signals over an audio plug are described herein. In some situations it is desirable and/or necessary to incorporate receptacles in host devices (e.g., portable audio players) that have limited depths such that they may physically receive audio plugs of limited length. In some situations, this may be limited to receiving TRS audio plugs (or audio plug with fewer contacts than a TRS plug) as TRRS plugs sized to satisfy industry standards may include a contact that is too close to the exterior of the product (e.g., the sleeve contact) thereby causing undesirable aesthetics. To facilitate data communication over such audio plugs, data may be communicated over the tip and ring contacts, contacts which are typically designed for communicating audio. To distinguish between an audio accessory (e.g., headphones) and a data communication accessory (e.g., a debug tool), the host device may monitor a voltage on the tip and/or ring contacts. Typical audio accessories are passive devices and thus do not output a voltage via the audio plug; rather, they receive audio signals over the audio plug. In contrast, a data communication accessory may output a voltage on the tip and/or ring contact to indicate to the host device that a data communication accessory has been plugged in via the audio plug receptacle and wishes to engage in data communication with the host device. After detecting such a voltage, the host device may begin data communication with the accessory of the tip and/or ring contacts. 
     In other embodiments a split-ring audio plug and methods for using the same are disclosed. In a split-ring audio plug, a standard audio plug contact (e.g., a ring contact) is physically separated along its length into two or more contacts, where each contact is electrically isolated from one another. As a result, a split-ring audio plug is formed that has an increased number of electrical contacts compared to a similar sized traditional audio plug. The contacts of the split-ring audio plug may be used for data and/or audio communication. In one particular embodiment, one or more of the contacts forming the split-ring may be used for data communication, whereas the tip and ring contacts may be used for left and right channel audio communication. It should be recognized, however, that embodiments are not limited to such specific processes for using a split-ring audio plug contact. 
     Turning now to the figures,  FIG. 1  illustrates a system for selectively establishing data communication or audio communication over an audio plug according to an embodiment. The system includes a host device  100 , an audio plug  200 , and an accessory  300 , where the audio plug  200  may be part of or separate from the accessory  300 . 
     Host device  100  may be any suitable electronic device that is operable to perform the functionality discussed herein, and may include one or more hardware and or software components operable to perform such functionality. For example, host device  100  may be a mobile phone, a personal digital assistant (PDA), a handheld or portable device (e.g., iPhone™, Blackberry™, etc.), a notebook, a personal computer, a note pad, a tablet computer, a media player (e.g., a music player or video player), a camera, a game player, a laptop computer, a netbook, a booklet, or other electronic device configured for wired and/or wireless communication. In one particular embodiment, host device  100  may be a portable media player. 
     Host device  100  includes a processor  110 , plug detection circuitry  120 , audio output circuitry  130 , data communication circuitry  140 , power supply  150 , memory  160 , and receptacle  170 . Processor  110  may be any computer microprocessor operable to perform one or more of the functions described herein, such as an ARM microprocessor, and in one embodiment may be operable to execute one or more instructions stored on a tangible non-transitory storage element such as memory  160 . Processor  110  may be communicatively coupled to other components of host device  100 , such as plug detection circuitry  120 , audio output circuitry  130 , data communication circuitry  140 , etc. 
     Plug detection circuitry  120  may be any hardware and/or software operable to detect the presence or absence of a plug inserted into receptacle  170 , and in some embodiments may be operable to determine whether the plug is only partially or fully inserted into receptacle  170 . Plug detection circuitry  120  in this embodiment is communicatively coupled to processor  110  and receptacle contact  174 . In other embodiments, the functionality of plug detection circuitry  120  may be incorporated into other components of host device  100 , such as processor  110 , audio output circuitry  130 , and/or data communication circuitry  140 . 
     Audio output circuitry  130  may be any hardware and/or software operable to communicate one or more audio signals from the host device to another device (e.g., accessory  330 ) via one or more receptacle contacts. Audio output circuitry  130  in this embodiment is communicatively coupled to processor  110  and receptacle contacts  174  and  176 . In one specific example, audio output circuitry  130  includes a left channel output communicatively coupled to receptacle contact  174  to output a left channel audio signal to receptacle contact  174 , and a right channel output communicatively coupled to receptacle contact  176  to output a right channel audio signal to receptacle contact  176 . It should be recognized, however, that these channel assignments are in no way intended to be limiting. Rather, in other embodiments, audio output circuitry  130  may be operable to output a right audio channel to receptacle contact  174  and a left audio channel to receptacle contact  176 , and/or one or more of mono audio signals, reversed stereo signals (reversal of the left and right channels), unbalanced or balanced audio signals, etc. Further, it should be recognized that some or all of the functionality described herein with reference to audio output circuitry  130  may be incorporated into other components of host device  100 , such as processor  110 . 
     Data communication circuitry  140  may be any hardware and/or software operable to communicate one or more data signals between the host device and another device (e.g., accessory  300 ) via one or more receptacle contacts. This communication may be unidirectional (from host device  100  to accessory  300  or from accessory  300  to host device  100 ) or bidirectional. Data communication circuitry  140  in this embodiment is communicatively coupled to processor  110  and receptacle contacts  174  and  176 . In other words, data communication circuitry  140  may be communicatively coupled to, and operable to receive data over, the same receptacle contacts used to output audio signals from the host device  100 . It should be recognized that while in this embodiment data communication circuitry  140  is graphically depicted as being separate from other components of host device  100 , in other embodiments some or all of the functionality described herein with reference to data communication circuitry  140  may be incorporated into other components of host device  100 , such as processor  110 . 
     Power supply  150  is any suitable power supply for providing operating power to one or more of the components of host device  100  and, in some embodiments, may provide power to accessory  300  over one or more of the receptacle contacts. Power supply  150  may include a battery, such as a rechargeable battery (lithium-ion, nickel metal hydride, nickel-zinc, nickel-cadmium, etc.), a non-rechargeable battery (alkaline, zinc-carbon, etc.), or other suitable type of battery. In some embodiments, power supply  150  may be coupled to an external power source, such as an AC power supply, that may be used to power host device  100  and/or recharge a battery included in host device  100 . 
     Memory  160  is any suitable electronic storage element and may include a tangible, non-transient storage element. For example, memory  160  may be one or more of random access memory (RAM), read only memory (ROM), electrically-erasable programmable read only memory (EEPROM), a hard disk, an optical disk, etc. In one embodiment, memory  160  may store software code that may be executed by processor  110  so that host device  100  performs one or more of the functional operations described herein. 
     Receptacle  170  is a receptacle connector operable to physically receive audio plug  200 . Receptacle  170  includes a cavity  172  sized and shaped to receive an insertion element  220  of audio plug  200 . To do so, cavity  172  may extend linearly from a surface of a housing of the host device  100  in a direction internal to the host device  100 . Cavity  172  may be cylindrical in shape and have a diameter sized to receive an audio plug such as a 2.5 mm plug, a 3.5 mm plug, a 6.3 mm plug, or other suitably sized audio plug. Accordingly, a diameter of cavity  172  may be slightly larger than the corresponding diameter of the audio plug the receptacle  170  is designed to receive. 
     Receptacle  170  includes a plurality of receptacle contacts for electrically contacting plug contacts on the audio plug  200 . In this embodiment, receptacle  170  includes a first receptacle contact  174  arranged to contact a tip contact  222  of the audio plug  200 , a second receptacle contact  176  arranged to contact ring contact  224  of the audio plug  200 , and a third receptacle contact  178  arranged to contact a sleeve contact  226  of the audio plug  200 , when the audio plug  200  is fully inserted into the receptacle  170 . The receptacle contacts may be any suitable style of electrical contact, such as a spring contact that moves in a direction away from plug  200  when plug  200  is inserted into receptacle  170 . It should be recognized that while in this embodiment the receptacle contacts are all provided on the same surface of receptacle  170  and are approximately equally spaced apart, in other embodiments they may be provided on different surfaces of receptacle  170  and have varied spacings therebetween. Moreover, while in this embodiment receptacle contacts  174  and  176  are electrically coupled to audio output circuitry  130  and data communication circuitry  140 , and receptacle contact  178  is coupled to an electrical ground, in other embodiments, the receptacle contacts may be coupled to other components of host device  100  and/or held to voltage levels other than ground. 
     Audio plug  200  may be any suitable plug that is shaped and operable to perform the functionality described herein. For example, audio plug  200  may be a 2.5 mm plug, a 3.5 mm plug, a 6.3 mm plug, or other plug connector having the shape of a plug that is typically suited for audio communication. Audio plug  200  in this embodiment includes a base  210  and insertion element  220 . Base  210  is operable to support the audio plug  200  for insertion of the insertion element  220  into and removal of the insertion element  220  from receptacle  170 . Base  210  may also be physically coupled to insertion element  220  and, as illustrated in this embodiment, may be cylindrically shaped and have a diameter larger than a diameter of the cylindrically shaped insertion element  220 . In other embodiments, base  210  may have a diameter less than or equal to the diameter of insertion element  220 . Base  210  may be made of any suitable material, including an insulating material such as a plastic or polymer. 
     Insertion element  220  extends linearly from base  210  and includes a plurality of contacts and insulating elements that are configured to electrically insulate the contacts from one another. The contacts of insertion element  220  also extend linearly from base  210 . In this particular embodiment, insertion element  220  includes a tip contact  222 , a ring contact  224 , and a sleeve contact  226 . Tip contact  222  is electrically insulated from ring contact  224  by an insulation ring  230 , and ring contact  224  is electrically insulated from sleeve contact  226  by insulation ring  232 . The sleeve contact  226  is also optionally insulated from other components of plug  200  by insulation ring  234 . 
     Audio plug  200  may also include one or more conductive elements disposed within the insertion element  220  for electrically coupling one or more components of accessory  300  to the plug contacts. For example, audio plug  200  may include a first conductive element  240  electrically coupled to tip contact  222 , a second conductive element  242  electrically coupled to ring contact  224 , and a third conductive element  244  electrically coupled to sleeve contact  226 . The conductive elements may be, e.g., insulated wires or other conductive component configured to electrically contact one or more of the plug contacts. It should be recognized that one or more of these conductive elements may be optional. For example, in at least one embodiment, sleeve contact  226  may be electrically coupled to, e.g., a ground, of accessory  300  by way of electrical contact with an electrically conductive base  210 , where the conductive base  210  may contact the ground of accessory  300 . This may be applicable in a number of different embodiments, including ones where insulation ring  234  is partially or wholly absent from plug  200 . It should be further recognized that the conductive elements may each be formed as a single element together with the respective contacts of the audio plug  200 . For example, in embodiments where the audio plug  200  is formed from numerous conductive elements that are inserted molded, press-fit, or the like, conductive elements (e.g., first conductive element  240 ) may be formed as a single component together with the corresponding contact (e.g., tip contact  222 ). 
     Accessory  300  may be any suitable electronic device that is operable to perform the functionality discussed herein, and may include one or more hardware and or software components operable to perform such functionality. For example, accessory  300  may be a mobile phone, a personal digital assistant (PDA), a handheld or portable device (e.g., iPhone™, Blackberry™, etc.), a notebook, a personal computer, a note pad, a tablet computer, a media player (e.g., a music player or video player), a camera, a game player, a laptop computer, a netbook, a booklet, or other electronic device configured for wired and/or wireless communication. In one particular embodiment, accessory  300  is a debugging tool. 
     Accessory  300  includes a processor  310 , data communication circuitry  320 , power supply  330 , and memory  340 . Processor  310  may be any computer microprocessor operable to perform one or more of the functions described herein, such as an ARM microprocessor, and in one embodiment may be operable to execute one or more instructions stored on a tangible non-transitory storage element such as memory  340 . Processor  310  may be communicatively coupled to other components of accessory  300 , such as data communication circuitry  320 , power supply  330 , memory  340 , etc. 
     Power supply  330  is any suitable power supply for providing operating power to one or more of the components of accessory  300  and, in some embodiments, may provide power to host device  100  over one or more of the receptacle contacts. Power supply  330  may include a battery, such as a rechargeable battery (lithium-ion, nickel metal hydride, nickel-zinc, nickel-cadmium, etc.), a non-rechargeable battery (alkaline, zinc-carbon, etc.), or other suitable type of battery. In some embodiments, power supply  330  may be coupled to an external power source, such as an AC power supply, that may be used to power accessory  300  and/or recharge a battery included in accessory  300 . 
     Memory  340  is any suitable electronic storage element and may include a tangible, non-transient storage element. For example, memory  340  may be one or more of random access memory (RAM), read only memory (ROM), electrically-erasable programmable read only memory (EEPROM), a hard disk, an optical disk, etc. In one embodiment, memory  340  may store software code that may be executed by processor  310  so that accessory  300  performs one or more of the functional operations described herein. 
     The system described with reference to  FIG. 1  in certain embodiments is a system for selectively establishing data communication or audio communication over an audio plug according to an embodiment, and includes a host device  100 , audio plug  200 , and accessory  300 . However, it will be appreciated by those of ordinary skill in the art that such a system could operate equally well with more or, in some instances, fewer components than are illustrated in  FIG. 1 . Similarly, it will be appreciated by those of ordinary skill in the art that each of the host device  100 , audio plug  200 , and accessory  300  could operate equally well with more or, in some cases, fewer components, than those described with reference to  FIG. 1 . For example, the host device  100  and/or accessory  300  may also include I/O elements such as keyboards, mice, touchscreens, graphical displays, and other components of electronic devices known in the art. Thus, the depictions in  FIG. 1  should be taken as being illustrative in nature, and not limiting to the scope of the disclosure. 
     Turning now to plug detection circuitry  120 , audio output circuitry  130 , and data communication circuitry  140 , in various embodiments such circuitry may perform a variety of functions such as determining whether an audio plug is mated with an audio receptacle connector of the host device, determining whether the audio plug is associated with an audio accessory (e.g., headphones) or a data communication accessory (e.g., a debug tool), and then performing the appropriate audio or data communication. Plug detection circuitry  120  may include any suitable circuitry for detecting a physical mating of a plug connector with the receptacle connector of the host device  100 , and thus may include mechanical switches, electrical contacts, optical sensors, and the like. Plug detection circuitry  120  is herein described as monitoring a voltage on receptacle contact  174 , but embodiments are not so limited. Once the presence of an audio plug is detected, audio/data detection circuitry may then determine whether the audio plug is associated with an audio accessory or a data communication accessory. Such audio/data detection circuitry may monitor a voltage on some of the audio plug contacts, such as those contacts that are typically designated for receiving audio in audio accessories (i.e., tip and ring contacts). If no voltage is present, then the audio/data detection circuitry may determine that the audio plug is associated with an audio accessory and thereby enable audio communication with the accessory. However, if a voltage is present, then the audio/data detection circuitry may determine that the audio plug is associated with a data communication accessory and thereby enable data communication with the accessory. Audio/data detection circuitry is herein described as being incorporated in data communication circuitry  140 , although embodiments are not so limited as such circuitry may be separate from data communication circuitry  140  or incorporated in other circuitry of the host device  100 . 
     Turning now to the figures,  FIG. 2A  is a schematic diagram of plug detection circuitry  120  according to an embodiment. Plug detection circuitry  120  according to this embodiment includes a transistor  120 A and resistors  120 B and  120 C. Transistor  120 A includes an emitter coupled to a positive voltage source, a base coupled to resistor  120 C, and a collector coupled to resistor  120 B and processor  110 . Resistor  120 B is coupled to the collector of transistor  120 A on one end and ground on the other end. Resistor  120 C is coupled to the base of transistor  120 A on one end and receptacle contact  174  on the other end. In operation, processor  110  may detect voltage changes at the collector of transistor  120 A indicative of whether a plug connector is disposed in the receptacle  170 . 
       FIG. 2B  is a schematic diagram of audio output circuitry  130  according to an embodiment. Audio output circuitry  130  includes a digital audio converter (DAC)  130 A and switches  130 B and  130 C. DAC  130 A operates to convert digital audio signals generated by host device  100  into audio signals that may be communicated to accessory  300  via receptacle  170 . In this particular embodiment, switches  130 B and  130 C are arranged between DAC  130 A and each of receptacle contact  174  and  176 , respectively. When in a closed position, switches  130 B and  130 C electrically connect (i.e., reduce electrical isolation between) audio output circuitry  130  and receptacle connectors  174  and  176 . When in an open position, switches  130 B and  130 C electrically disconnect (i.e., increase electrical isolation between) audio output circuitry  130  and receptacle connectors  174  and  176 . Switches  130 B and  130 C may be coupled to processor  110  via a control line (CTRL) such that processor  110  may control the state (e.g., open or closed) of switches  130 B and  130 C. Further, processor  110  may be coupled to DAC  130 A so as to communicate digital audio signals to DAC  130 A. In one particular embodiment and as illustrated in  FIG. 2B , audio output circuitry  130  may be operable to output a left audio channel to receptacle contact  174  and a right audio channel to receptacle contact  176 . However, in other embodiments audio output circuitry  130  may output different audio channels and/or signals to the receptacle contacts. 
       FIG. 2C  is a schematic diagram of data communication circuitry  140  according to an embodiment. Data communication circuitry  140  includes a first transistor  140 A (e.g., a BJT), a second transistor  140 B (e.g., an IGFET), resistors  140 C,  140 D, and  140 E, inverters  140 F and  140 G, and switches  140 H and  140 I. Transistor  140 A includes an emitter coupled to ground, a base coupled to resistor  140 C, and a collector coupled to switch  140 H. Switch  140 H is also coupled to receptacle contact  174 . Resistor  140 C is coupled between the base of transistor  140 A and inverter  140 F. The other side of inverter  140 F is coupled to processor  110  to receive a data signal from processor  110 . Transistor  140 A and its associated circuitry are operable to communicate data from processor  110  to receptacle contact  174 . 
     Transistor  140 B includes a source coupled to resistor  140 E and ground, a gate coupled to the other side of resistor  140 E and switch  140 I, and a drain coupled to resistor  140 D and inverter  140 G. Resistor  140 E is coupled between ground and switch  140 I, and switch  140 I is also coupled to receptacle contact  176 . Resistor  140 D is coupled to the drain of transistor  140 B and inverter  140 G on one end, and to a positive voltage source on the other end. The other end of inverter  140 G is coupled to processor  110  to send a data signal to processor  110 . 
     Transistor  140 B and its associated circuitry are operable to detect a signal, e.g., a positive voltage, at receptacle contact  176 , and receive data over receptacle contact  176 . That is, when a positive voltage (with reference to the electrical ground) is provided to receptacle contact  176 , RX/DETECT is pulled high. This may be the case when a debug tool or other electronic device desires to communicate data with electronic device  100  over receptacle contacts  174  and  176  that are typically used only to output audio from electronic device  100 . When a positive voltage is detected at receptacle contact  176 , electronic device  100  may then recognize that a debug tool or other electronic device desires to communicate data with electronic device  100  over the audio contacts, and thus electronic device may begin communicating data via receptacle contacts  174  and  176 . For example, electronic device  100  may send data via the TX line coupled to receptacle contact  174  and receive data via the RX/DETECT line coupled to receptacle contact  176 . It should be recognized that in some embodiments the TX and RX_DETECT circuitry may be switched so that electronic device  100  can detect and receive data signals over receptacle contact  174  and send data signals over receptacle contact  176 . Further, when there is no voltage detected at receptacle contact  176 , electronic device  100  may determine that a standard audio accessory has been connected thereto, and thus may send audio to the audio accessory using audio output circuitry  130 . 
     Switches  140 H and  140 I, when in a closed position, electrically connect (i.e., reduce electrical isolation between) data communication circuitry  140  and receptacle connectors  174  and  176 . When in an open position, switches  140 H and  140 I electrically disconnect (i.e., increase electrical isolation between) data communication circuitry  140  and receptacle connectors  174  and  176 . Switches  140 H and  140 I may be coupled to processor  110  via a control line (CTRL) such that processor  110  may control the state (e.g., open or closed) of switches  140 H and  140 I. 
     Plug detection circuitry  120 , audio output circuitry  130 , and data communication circuitry  140  in certain embodiments include a variety of components as illustrated in and described with reference to  FIGS. 2A through 2C . However, it will be appreciated by those of ordinary skill in the art that such circuitry could operate equally well with more or, in some instances, fewer components than are illustrated in  FIGS. 2A through 2C . Thus, the depictions in  FIGS. 2A through 2C  should be taken as being illustrative in nature, and not limiting to the scope of the disclosure. 
     Some or all of the components described with reference to  FIGS. 1 through 2C  may be used to perform a process for selectively establishing data communication or audio communication over an audio plug. As described, in some embodiments the host device may detect engagement of an audio plug with a receptacle connector of the host device and subsequently determine whether the audio plug is associated with an audio accessory or data communication accessory. In some embodiments, the host device may be placed in a default state where it presumes a data communication accessory will be plugged in. In such a case, the host device may isolate audio output circuitry from the receptacle contacts so as to reduce interference, and may electrically connect data communication circuitry to the receptacle contacts to facilitate the presumed data communication. After an audio plug has been inserted into the host device, if the audio plug is indeed associated with a data communication device, then the host device may simply begin communicating data with the data communication device. However, if the audio plug is actually associated with an audio device, then the host device may disconnect the data communication circuitry from the receptacle contacts (so as to reduce interference) and connect the audio output circuitry to the receptacle contacts (so as to facilitate audio communication). 
     The process described with reference to  FIG. 3  includes operations similar to those described above, where it is presumed that the audio plug is associated with a data communication device. However, in other embodiments, the opposite may be true. That is, the host device may presume that the audio plug is associated with an audio device. In such a case, the audio output circuitry may initially be coupled to the receptacle contacts whereas the data communication circuitry may initially be isolated from those contacts. In other embodiments, there may be no presumptions, in which case both of the audio output circuitry and data communication circuitry may be isolated from the receptacle contacts and subsequently coupled thereto only after determining whether the audio plug is associated with an audio device or data communications device. One skilled in the art would recognize numerous variations. 
     Turning now to the figures,  FIG. 3  illustrates a process  400  of a host device for selectively establishing data communication or audio communication over an audio plug according to an embodiment. While described with reference to  FIGS. 1 through 2C , it should be recognized that embodiments are not so limited. 
     In operation  402 , an electrical connection between audio output circuitry (e.g., audio output circuitry  130 ) and receptacle contacts operable to communicate audio signals from the audio output circuitry (e.g., receptacle contacts  174  and  176 ) is disabled. For example, processor  110  may control switches  130 B and  130 C to operate in an open state, thereby disabling the electrical connection (i.e., increasing the electrical impedance) between audio output circuitry  130  and receptacle contacts  174  and  176 . 
     In operation  404 , an electrical connection between data communication circuitry (e.g., data communication circuitry  140 ) and the receptacle contacts (e.g., receptacle contacts  174  and  176 ) is enabled. For example, processor  110  may control switches  140 H and  140 I to operate in a closed state, thereby enabling the electrical connection (i.e., decreasing the electrical impedance) between data communication circuitry  140  and receptacle contacts  174  and  176 . 
     In operation  406 , it is determined whether engagement with a plug connector shaped like an audio plug is detected. For example, processor  110  may monitor a voltage between transistor  120 A and resistor  120 B of plug detection circuitry  120  and, when a voltage is detected, determine that a plug connector shaped like an audio plug has been fully inserted into receptacle  170 . If it is determined that a plug connector has not yet been fully engaged with the receptacle connector, then processing may return to operation  406  where host device  100  continues to monitor for such an engagement. Otherwise, processing may continue to operation  408 . 
     In operation  408  it is determined whether a signal is received on one of the receptacle contacts that is operable to communicate audio signals from the audio output circuitry. For example, processor  110  may monitor a voltage output from inverter  140 G. When a positive voltage is supplied to receptacle connector  176 , the voltage output from inverter  140 G will change from a low state to a high state. When the processor  110  identifies a high voltage output by inverter  140 G, it determines that a signal is received on one of the receptacle contacts  174  and  176 . In other embodiments, processor  110  may need to receive a particular string of bits or data to determine that a signal is received on one of the receptacle contacts. When it is determined that a signal is received on one of the receptacle contacts, this is indicative of an accessory being coupled to host device where the accessory desires to engage in data communication. Accordingly, processing may continue to operation  410 . 
     In operation  410 , data is communicated via the data communication circuitry (e.g., data communication circuitry  140 ) and the receptacle contacts that are also operable to communicate audio from the audio output circuitry (e.g., receptacle contacts  174  and  176 ). For example, data may be transmitted from host device  100  to accessory  300  via transistor  140 A and receptacle contact  174 , and data may be received from accessory  300  by host device  100  via transistor  140 B and receptacle contact  176 . In one particular embodiment, data communicated via the receptacle contacts may include handshake data suitable for establishing communication between host device  100  and accessory  300  in accordance with a particular data communication protocol. 
     Processing may then continue to operation  412  where it is determined whether a disengagement from the plug connector is detected. For example, processor  110  may detect a change in voltage between transistor  120 A and resistor  120 B indicative of the audio plug being removed from the receptacle connector. When it is determined that the audio plug has not been removed from the receptacle connector, processing may return to operation  412  where the host device  100  continues to monitor for removal of the audio plug (in some cases, simultaneously with communicating data). Otherwise, processing may return to operation  406  where the host device  100  monitors for re-engagement with the audio plug. 
     Returning to operation  408 , when it is determined that a signal is not received on one of the receptacle contacts that is operable to communicate audio signals from the audio output circuitry (e.g., for a certain period of time after detecting engagement with the plug connector), this is indicative of an accessory being coupled to a host device where the accessory desires to engage in audio communication. Accordingly, processing may continue to operation  414 . 
     In operation  414  the electrical connection between data communication circuitry (e.g., data communication circuitry  140 ) and the receptacle contacts (e.g., receptacle contacts  174  and  176 ) is disabled. For example, processor  110  may control switches  140 H and  140 I to operate in an open state, thereby disabling the electrical connection (i.e., increasing the electrical impedance) between data communication circuitry  140  and receptacle contacts  174  and  176 . 
     In operation  416 , the electrical connection between audio output circuitry (e.g., audio output circuitry  130 ) and receptacle contacts operable to communicate audio signals from the audio output circuitry (e.g., receptacle contacts  174  and  176 ) is enabled. For example, processor  110  may control switches  130 B and  130 C to operate in a closed state, thereby enabling the electrical connection (i.e., reducing the electrical impedance) between audio output circuitry  130  and receptacle contacts  174  and  176 . 
     In operation  418 , audio is communicated from the host device to the accessory via audio output circuitry (e.g., audio output circuitry  130 ) and the receptacle contacts (e.g., receptacle contacts  174  and  176 ). For example, a digital audio signal may be output by processor  110  to audio output circuitry  130 , DAC  130 A may convert the digital audio signal into an analog waveform, and the analog waveform may be transmitted to accessory  300  via receptacle contacts  174  and  176 . In one particular embodiment, a left stereo channel may be transmitted via receptacle contact  174  and a right stereo channel may be transmitted via receptacle contact  176 . 
     Processing may then continue to operation  420  where it is determined whether a disengagement from the plug connector is detected. For example, processor  110  may detect a change in voltage between transistor  120 A and resistor  120 B indicative of the audio plug being removed from the receptacle connector. When it is determined that the audio plug has not been removed from the receptacle connector, processing may return to operation  420  where the host device  100  continues to monitor for removal of the audio plug (in some cases, simultaneous with communicating audio). Otherwise, processing may return to operation  402  where the host device  100  disables the electrical connection between the audio output circuitry and receptacle contacts and re-enables the electrical connection between the data communication circuitry and receptacle contacts. 
     It should be appreciated that the specific operations illustrated in  FIG. 3  provide a particular process of a host device for selectively establishing data communication or audio communication over an audio plug according to an embodiment. The various operations described with reference to  FIG. 3  may be implemented at and performed by one or more of a variety of electronic devices or components described herein, such as host device  100 . Other sequences of operations may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the operations outlined above in a different order. Moreover, the individual operations illustrated in  FIG. 3  may include multiple sub-operations that may be performed in various sequences as appropriate to the individual operations. Furthermore, additional operations may be added or existing operations removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives. 
     In addition to processes for a host device determining whether to engage in audio or data communication being disclosed, some embodiments are also directed to processes for operating an accessory (e.g., a debug tool) to communicate data over contacts of an audio plug that are typically used for audio communication. In such embodiments, the accessory first indicates to the host device that it is an accessory desiring to communicate data over such contacts. In the embodiments described herein, the accessory does this by setting a voltage of one of those contacts (e.g., the tip contact or ring contact of an audio plug) high or by sending some particular string of data over one or more of those contacts. If the accessory receives a response comprising some data communication, then the accessory may determine that the host device has properly identified the accessory as being a data communication accessory. However, if the accessory does not receive such a response, then the accessory may determine that the host has not yet recognized the accessory as being a data communication accessory and thus may not be in a state suitable for data communications. Accordingly, the accessory may again attempt to notify the host device that it is an accessory operable to engage in data communication and may continue to do so until it receives a suitable response from the host device. 
     Turning to the figures,  FIG. 4  illustrates a process  450  of an accessory for establishing data communication over an audio plug according to an embodiment. While described with reference to  FIGS. 1 through 3 , it should be recognized that embodiments are not so limited. 
     In operation  452  a signal is output via a tip contact or a ring contact of a plug connector shaped like an audio plug. For example, data communication circuitry  320  may output a voltage or other signal (such as a sequence of bits) to ring contact  224  of audio plug  200  via the conductive element  242 . Such signal may be generated and communicated by accessory  300  to indicate to host device  100  that accessory  300  desires to engage in data communication via the audio plug  200 . 
     In operation  454  it is determined whether a response is received over one of the tip contact or the ring contact from the electronic device. For example, data communication circuitry  320  may monitor tip contact  222  to determine whether any voltage or other signal (e.g., a handshake signal) is received at the tip contact  222 . If it is determined that a response is not received within a particular time period, then processing may return to operation  452  where the accessory again (or continues to) output a signal via the tip contact or ring contact. Otherwise, processing may continue to operation  456 . 
     In operation  456  data communication is established over the tip contact and the ring contact with the electronic device. For example, data communication circuitry  320  may communicate data to host device  100  via ring contact  224  and conductive element  242 , where such data is received by transistor  140 B via receptacle contact  176  of host device  100 . Data communication circuitry  320  may receive data from host device  100  via tip contact  222  and conductive element  240 , where such data is communicated by transistor  140 A via receptacle contact  174  of host device  100 . 
     In operation  458  accessory  300  may determine whether removal of the plug connector (e.g., audio plug  200 ) from the electronic device (e.g., receptacle  170  of host device  100 ) has been detected. For example, data communication circuitry  320  may monitor the communications between accessory  300  and host device  100  and, if data is lost for a certain period of time, determine that audio plug  200  has been removed from receptacle  170 . For another example, accessory  300  may include plug detection circuitry (similar to that described with reference to host device  100 ) operable to determine whether audio plug  200  is fully inserted into receptacle  170 . When it is determined that the audio plug has not been removed from the receptacle connector, processing may return to operation  458  where the accessory  300  continues to monitor for removal of the audio plug (in some cases, simultaneously with performing data communication). Otherwise, processing may return to operation  452  where the accessory again outputs a signal via the tip contact or ring contact of the audio plug. 
     It should be appreciated that the specific operations illustrated in  FIG. 4  provide a particular process of an accessory for establishing data communication over an audio plug according to an embodiment. The various operations described with reference to  FIG. 4  may be implemented at and performed by one or more of a variety of electronic devices or components described herein, such as accessory  300 . Other sequences of operations may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the operations outlined above in a different order. Moreover, the individual operations illustrated in  FIG. 4  may include multiple sub-operations that may be performed in various sequences as appropriate to the individual operations. Furthermore, additional operations may be added or existing operations removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives. 
     While one technique for facilitating data communication with over a limited sized audio plug connector (e.g., a TRS audio plug) includes communicating data over contacts typically reserved for audio communication, in other techniques such data communication may be facilitated by increasing the number of available plug contacts within a similarly spaced audio plug. This may be done, for example, by splitting the contacts of the audio plug (e.g., a TRS audio plug) into multiple contacts. For example, the tip contact, ring contact, and/or the sleeve contact may each be split into multiple independent contacts. Various embodiments for such splitting and uses thereof are further described herein. 
     Turning now to  FIGS. 5A through 7B , these figures illustrate simplified split-ring plug connectors according to various embodiments. Specifically,  FIG. 5A  illustrates a side view of a simplified split-ring plug connector  500  according to a first embodiment, and  FIG. 5B  illustrates a cross-sectional view  520  of the split-ring plug connector  500  of  FIG. 5A  through plane A-A. The split-ring plug connector according to this embodiment is similar to the audio plug  200  described with reference to  FIG. 1  at least with respect to elements that are identically labeled, thus further description of such elements is omitted. However, in contrast to the audio plug  200  of  FIG. 1 , which includes a sleeve contact  226 , the split-ring plug connector according to this embodiment includes a split-ring contact  502  arranged between insulation rings  232  and  234 . The split-ring contact  502  includes a first contact  504  and a second contact  506  that are electrically isolated from one another by insulation elements  508  and  510 . 
     In this particular embodiment, contacts  504  and  506  are arranged opposite one another with respect to a plane extending linearly from the base  210  to the tip of the insertion element  220 . The insulation elements  508  and  510  similarly extend linearly from the base  210  toward the tip of insertion element  220  and along the insertion element  210 . The insulation elements  508  and  510  also extend perpendicular to the insulation rings (although in other embodiments they may be angled with respect to the insulation rings). In this particular embodiment, the contacts  504  and  506  extend the same length from base  210 . However, in other embodiments, contacts  504  and  506  may have different lengths and/or may be offset with respect to one another along the axis extending linearly from the base  210  to the tip of the insertion element  220 . 
     With reference to the cross-sectional view  520  of the split-ring connector plug, the contacts  504  and  506  are cylindrically shaped such that they only partially circumscribe the axis extending linearly from the base  210  to the tip of the insertion element  220 . This is in contrast to other contacts of the split-ring connector plug, such as ring contact  224 , which is cylindrically shaped and fully circumscribes that axis. In this particular embodiment, the split-ring connector plug includes wires  512  formed of a conductive element  512 A surrounded by an insulative sheath  512 B. The wires  512  are supported in the split-ring connector plug by insulation material  514  which may be any suitable dielectric material with insulating properties. Such wires  512  may be electrically coupled to various contacts of the split-ring plug connector, and may extend out of the split-ring plug connector for electrical connection with accessory  300 . 
       FIG. 6A  illustrates a side view of a simplified split-ring plug connector  530  according to a second embodiment, and  FIG. 6B  illustrates a cross-sectional view  550  of the split-ring plug connector  530  through plane B-B. The split-ring plug connector according to this embodiment is similar to that described with reference to  FIG. 5A  and  FIG. 5B  at least with respect to elements that are identically labeled, thus further description of such elements is omitted. However, in contrast to the split-ring plug connector of  FIG. 5A  and  FIG. 5B , which includes a split-ring contact  502  including two contacts  504  and  506 , the split-ring contact  532  in this embodiment includes three contacts  534 ,  536 , and  538 . The first contact  534  is electrically insulated from the second contact  536  by insulation element  540 , the second contact  536  is electrically insulated from the third contact  538  by insulation element  542 , and the third contact  538  is electrically insulated from the first contact  534  by insulation element  544 . 
       FIG. 7A  illustrates a side view of a simplified split-ring plug connector  560  according to a third embodiment, and  FIG. 7B  illustrates a cross-sectional view  580  of the split-ring plug connector  560  through plane C-C. The split-ring plug connector according to this embodiment is similar to that described with reference to  FIG. 5A  and  FIG. 5B  at least with respect to elements that are identically labeled, thus further description of such elements is omitted. However, in contrast to the split-ring plug connector of  FIG. 5A  and  FIG. 5B , which includes a split-ring contact  502  including two contacts  504  and  506 , the split-ring contact  562  in this embodiment includes four contacts  564 ,  566 ,  568 , and  570 . The first contact  564  is electrically insulated from the second contact  566  by insulation element  572 , the second contact  566  is electrically insulated from the third contact  568  by insulation element  574 , the third contact  568  is electrically insulated from the fourth contact  570  by insulation element  576 , and the fourth contact  570  is electrically insulated from the first contact  564  by insulation element  578 . 
     It should be recognized that the split-ring plug connectors described with reference to  FIGS. 5A through 7B  are merely examples and not intended to limit the scope of the embodiments described herein. For example, in some embodiments, the split ring contact may be arranged at different portions of the insertion element, such as at ring contact  224 . In some embodiments, there may no sleeve contact, but rather only a tip contact and split-ring contact. In some embodiments, there may be two, three, or more ring contacts, any of which may be split-ring contacts. In some embodiments, more than one of the contacts (e.g., two of the ring contacts) may be split-ring contacts. Further, in some embodiments the contacts forming a split-ring contact may not have the same length or width. For example, with respect to length, the contacts forming a split-ring contact may extend to the same or different lengths from the base  210 . With respect to width and with reference to cross-sectional view  520 , contact  504  may circumscribe the aforementioned axis more or less (e.g., forming 60 degrees of the circumference of the plug) than that of contact  506  (e.g., forming 280 degrees, where the remaining 20 degrees are formed by insulation elements  508  and  510 ). Further yet, in at least one embodiment, one or more of the contacts forming a split-ring contact may not be conductive but rather may be insulative. For example, with reference to  FIG. 5A , contact  504  may be an electrical insulator rather than an electrical conductor, and in one embodiment may form a single insulative component together with other insulation elements such as insulation elements  508  and  510 . One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives. 
     In some embodiments the conductive elements of each plug may be formed together with respective contacts of the plug as single elements and assembled together by insert molding, press-fitting, or the like.  FIGS. 8A through 8C  illustrate one example of such an embodiment. 
     Specifically,  FIG. 8A  illustrates an isometric view a split-ring plug connector  600  according to an embodiment,  FIG. 8B  illustrates a cross-sectional view  650  of the split-ring plug connector  600  of  FIG. 8A  through a plane extending along the length of and through the center of the plug connector  600  (i.e., through line D), and  FIG. 8C  illustrates a cross-sectional view  680  of the split-ring plug connector  600  of  FIG. 8A  through a plane extending perpendicular to the length of connector  600  (i.e., through line E-E). 
     Similar to the embodiment described with reference to  FIGS. 5A and 5B , the split-ring plug connector  600  according to this embodiment includes a base  210 , an insertion element  220 , tip contact  222 , ring contact  224 , insulation ring  230 , insulation ring  232 , insulation ring  234 , and split-ring contact  502  that includes a first contact  504  and a second contact  506  that are electrically isolated from one another by insulation elements  508  and  510 . Split-ring plug connector  650  further includes a sleeve contact  511  arranged between the split-ring contact  502  and base  210  that, in this embodiment, is electrically insulated from base element  210  via insulation ring  513 . 
     As illustrated in  FIG. 8B  and  FIG. 8C , the split-ring plug connector  500  includes a number of single components that are assembled together. For example, conductive element  240  may be press-fit or crimped into tip  222 . The resulting tip structure is assembled (e.g., via insert molding) with insulation ring  230  that not only traverses the circumference of the plug but also extends along the length of the plug surrounding (and in contact with) the conductive element  240  of tip  222 . The ring contact  224  is then assembled onto the resulting structure and includes not only a conductive element that is exposed and traverses the circumference of the plug but also extends along the length of the plug surrounding (and in contact with) insulation ring  230 . The split-ring contact  502  is then assembled onto the resulting structure. The split-ring contact includes insulation ring  232  that is arranged similar to insulation ring  230  but in this case extends along and electrically isolates the non-exposed portion of ring contact  224 . The illustrated half of the split-ring contact  502  also includes second contact  506  that circumscribes only a portion of the periphery of the plug (e.g., the bottom half). The second contact  506  includes an exposed portion and an unexposed portion that extends along the length of the plug partially surrounding (e.g., surrounding the bottom half) and in contact with insulation ring  232 . The first contact  508  is similarly arranged but on the opposite side of the plug. The split-ring contact  502  further includes insulation ring  234  that is arranged similar to insulation ring  232  but in this case extends along and electrically isolates the non-exposed portion of the split-ring contact  502 . The sleeve contact  511  is then formed over the insulation ring  234  and, in this embodiment, electrically isolated from base  210  via insulation ring  513 . 
     It should be recognized that the split-ring plug connectors described with reference to  FIGS. 8A through 8C  are merely examples and not intended to limit the scope of the embodiments described herein. For example, the split-ring contact  502  may include more than two contacts, may be arranged in a different position of the plug connector (e.g., in place of ring contact  224  and/or sleeve contact  511 ), and the plug may include or exclude sleeve contact  511 . Other variations as described with reference to other figures, such as  FIGS. 5A to 7B , may also be applied to the embodiments described with reference to  FIGS. 8A through 8C . Thus, one of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives. 
     The split-ring plug connector described herein may be used to facilitate a variety of data and/or audio communications. Due to the increased number of contacts over typical audio plugs, the split-ring plug connector may easily support multiple, even simultaneous, types of audio and data communication. Embodiments described herein focus on using such a plug connector for data communication. However, it should be recognized that embodiments are not so limited, as the same plug connector could similarly be used for audio communication and/or data communication. 
       FIG. 9  illustrates a system for establishing data communication and/or audio communication over a split-ring audio plug according to an embodiment. The system includes a host device  100 , an audio plug  200 , and an accessory  300 . The system according to this embodiment is similar to that described with reference to  FIG. 5A , with various differences described herein. 
     Audio plug  200  according to this embodiment is similar to the audio plug described with reference to  FIG. 1 , but in this embodiment includes a split-ring contact  502 . The split-ring contact  502  in this particular embodiment includes two contacts  504  and  506  electrically insulated from one another by insulation element  508 , similar to the split-ring plug described with reference to  FIG. 5A . Audio plug  200  also includes conductive elements  240  and  242 , where conductive element  240  is electrically coupled to tip contact  222  and conductive element  242  is electrically coupled to contact  506  of split-ring contact  502 . 
     However, other embodiments are not so limited. That is, any of the split-ring plugs described herein may be used in place of audio plug  200 , where each split-ring plug may include a suitable number of conductive elements electrically coupled to its contacts so as to facilitate electrical connection with accessory  300 . For example, with reference to  FIG. 6A , conductive elements may be coupled to one or more of first contact  534 , second contact  536 , and third contact  538 . In one embodiment, whether or not conductive elements are coupled to contacts of a split-ring contact may be based on whether the contacts are being used to communicate audio and/or data. 
     Audio plug  200  may also include a keying element  509  shaped to mate with a keying receptacle  179  of the host device  100 . The keying element  509  operates to ensure that audio plug  200  mates with receptacle  170  in only one or a limited number of orientations so that the contacts forming split-ring contact  502  are oriented to contact the appropriate receptacle contacts. However, in other embodiments, techniques may be implemented such that a keying element  509  is not necessary. For example, the receptacle connector  170  may include redundant or otherwise strategically located contacts (so as to ensure at least one of the split-ring contacts is electrically connected to upon engagement of the plug connector). 
     Host device  100  according to this embodiment is similar to the host device described with reference to  FIG. 1 , but in this embodiment includes an additional receptacle contact  177 . Receptacle contacts  177  and  178  are arranged in receptacle  170  so that upon mating with audio plug  200 , receptacle contacts  177  and  178  electrically contact the contacts  506  and  504 , respectively, of split-ring contact  502 . Further, rather than receptacle contact  176  being coupled to both audio output circuitry  130  and data communication circuitry  140 , receptacle contact  176  is coupled to only audio output circuitry  130  whereas receptacle contact  177  is coupled to data communication circuitry  140  as is receptacle contact  174 . Accordingly, upon mating of audio plug  200  and receptacle  170 , data communication may be facilitated over receptacle contacts  174  and  177  which are electrically coupled to tip ring  222  and contact  506  of split-ring contact  502 , respectively. 
     Data communication circuitry  140  may be operable to send and receive data over the receptacle contacts of receptacle  170 . One of the challenges in incorporating both data communication circuitry and audio output circuitry is possible noise interference between the transmission lines, especially where data output is performed over the same contacts as audio output. Such interference may be reduced by electrically isolating either the audio output circuitry  130  or data communication circuitry  140  when not in use, such as via switches  130 B,  130 C,  140 H, and/or  140 I. However, in some embodiments, in addition or alternatively to using such switches, the data output may be performed over one or more receptacle contacts that are not shared with audio output. 
     For example, in one particular embodiment, data communication circuitry  140  is operable to receive data over receptacle contact  174  (using, e.g., transistor  140 B and its associated circuitry) and transmit data over receptacle contact  177  (using, e.g., transistor  140 A and its associated circuitry). In such a case, the data transmission line is naturally isolated from receptacle contacts  174  and  176 , and thus audio output circuitry  130 , thereby reducing noise interference between the audio and data transmission lines. Accordingly, in this embodiment, data communication circuitry  320  of accessory  300  may be operable to transmit data over tip contact  222  and receive data over contact  506  of split-ring contact  502 . Further, in some embodiments, noise may be reduced even further by forming one or more of the contacts of plug  200  using insulative rather than conductive material. For example, ring contact  224  may be formed as an insulator rather than a conductor. For another example, where a ground is not needed for data communication, first contact  504  of split-ring contact  502  may be formed as an insulator rather than a conductor. 
     The system described with reference to  FIG. 9  in certain embodiments is a system for establishing data communication and/or audio communication over a split-ring audio plug according to an embodiment, and includes a host device  100 , audio plug  200 , and accessory  300 . The specific example described with reference to  FIG. 9  includes communicating data over particular receptacle contacts that mate with particular plug contacts. However, it should be recognized that embodiments are not so limited. 
     For example, a variety of audio plugs incorporating a variety of different types of split-ring contacts, e.g., the split-ring contacts described with reference to  FIGS. 5A to 8C , may be used. Similarly, receptacle contacts may be arranged in receptacle  170  to electrically contact one or more of the contacts of audio plug  200  including one or more contacts of one or more split-ring contacts forming audio plug  200 . 
     Audio output circuitry  130  and data communication circuitry  140  may similarly be configured to communicate audio and/or data over any of the contacts of receptacle  170 . For example, audio output circuitry  130  may be coupled to one or more receptacle contacts that electrically contact one or more contacts forming a split-ring contact. Data communication circuitry  140  may be coupled to more than one receptacle contact that electrically contacts more than one contact forming a split-ring contact, so that data is communicated exclusively over a split-ring contact. Both audio output circuitry  130  and data communication circuitry  140  may be coupled to receptacle contacts that electrically contact contacts forming a split-ring contact so that both audio and data is communicated over one or more split-ring contacts. 
     Similarly, data communication circuitry  320  may be coupled to plug contacts different than tip contact  222  and contact  506  of split ring  502  so that accessory  300  may communicate data and/or audio over any contacts of plug  200 . For example, data communication circuitry  320  may be coupled to and communicate data via multiple contacts forming split-ring contact  502 . Data communication circuitry  320 , in some embodiments, may also or alternatively be operable to communicate audio signals over an audio plug  200  incorporating one or more split-ring contacts  502 . For example, data communication circuitry  302  may be operable to receive audio signals over split-ring contact  504  and/or  506 . For another example, data communication circuitry  302  may be operable to communicate audio over some contacts of audio plug  200  (e.g., tip contact  222  and ring contact  224 ) and communicate data over other contacts of audio plug  200  (e.g., contacts  504  and  506 ). 
     It will be appreciated by those of ordinary skill in the art that the system described with reference to  FIG. 9  could operate equally well with more or, in some instances, fewer components than are illustrated in  FIG. 9 . Similarly, it will be appreciated by those of ordinary skill in the art that each of the host device  100 , audio plug  200 , and accessory  300  could operate equally well with more or, in some cases, fewer components, than those described with reference to  FIG. 9 . For example, the host device  100  and/or accessory  300  may also include I/O elements such as keyboards, mice, touchscreens, graphical displays, and other components of electronic devices known in the art. Further, it should be recognized that while audio connector  200  may be physically separate from accessory  300 , in some embodiments audio connector  200  may be considered part of the accessory  300 . Thus, the depictions in  FIG. 9  should be taken as being illustrative in nature, and not limiting to the scope of the disclosure. 
     Some or all of the components described with reference to  FIG. 9  may be used to perform a process for selectively establishing data communication or audio communication over an audio plug. As described with reference to  FIG. 3 , in some embodiments the host device may detect engagement of an audio plug with a receptacle connector of the host device and subsequently determine whether the audio plug is associated with an audio accessory or data communication accessory. Rather than communicating data using the same contacts that are typically used for audio communication, in embodiments incorporating a split-ring contact data (and/or audio) may be communicated over at least one of the contacts forming the spilt-ring contact. Such embodiments may incorporate steps for actively reducing interference by intelligently connecting and disconnecting audio output circuitry and data communication circuitry from the receptacle contacts, but in many embodiments such steps may be obviated due to the natural electrical isolation achievable with the increased number of plug contacts. 
       FIG. 10  illustrates a process  600  of a host device for selectively establishing data communication or audio communication over an audio plug having a split-ring contact according to an embodiment. While described with reference to  FIGS. 1 through 9 , it should be recognized that embodiments are not so limited. 
     In operation  602 , an electrical connection between audio output circuitry (e.g., audio output circuitry  130 ) and receptacle contacts operable to communicate audio signals from the audio output circuitry (e.g., receptacle contacts  174  and  176 ) is optionally disabled, and an electrical connection between data communication circuitry (e.g., data communication circuitry  140 ) and the receptacle contacts (e.g., receptacle contacts  174  and  177 ) is optionally enabled. This operation is similar to operations  402  and  404 , except in this case may be optionally performed as the transmission components of data communication circuitry  140  and audio output circuitry  130  may be naturally isolated from one another. Notwithstanding such operations being indicated as optional in this embodiment, it should be recognized that the corresponding operations previously described with reference to  FIG. 3  (i.e., operations  402  and  404 ) may similarly be optional. 
     In operation  604  it is determined whether engagement with a plug connector shaped like an audio plug is detected. This operation is similar to operation  406 , and thus further description is omitted. If it is determined that a plug connector has not yet been fully engaged with the receptacle connector, then processing may return to operation  602  where host device  100  continues to monitor for such an engagement. Otherwise, processing may continue to operation  606 . 
     In operation  606  it is determined whether a signal is received on one of the receptacle contacts. This operation is similar to operation  408 . However, in this case, it may be determined whether a signal is received on any of the receptacle contacts including one or more contacts forming one or more split-ring contacts  502 . When it is determined that a signal is received on one of the receptacle contacts, this is indicative of an accessory being coupled to a host device where the accessory desires to engage in data communication. Accordingly, processing may continue to operation  608 . 
     In operation  608 , data is communicated via the data communication circuitry (e.g., data communication circuitry  140 ) and receptacle contacts including at least one receptacle contact (e.g., receptacle contact  177 ) in physical contact with a split-ring contact (e.g., contact  506 ) of the plug connector. For example, data may be transmitted from host device  100  to accessory  300  via receptacle contact  177 , and data may be received from accessory  300  by host device  100  via receptacle contact  174 . In one particular embodiment, data communicated via the receptacle contacts may include handshake data suitable for establishing a particular data communication between host device  100  and accessory  300 . 
     Processing may then continue to operation  610  where it is determined whether a disengagement from the plug connector is detected. Operation  610  is similar to operation  412 , thus further description is omitted. When it is determined that the audio plug has not been removed from the receptacle connector, processing may return to operation  610  where the host device  100  continues to monitor for removal of the audio plug. Otherwise, processing may return to operation  604  where the host device  100  monitors for re-engagement with the audio plug. 
     Returning to operation  606 , when it is determined that a signal is not received on one of the receptacle contacts that is operable to communicate audio signals from the audio output circuitry, this is indicative of an accessory being coupled to host device where the accessory desires to engage in audio communication. Accordingly, processing may continue to operation  612 . 
     In operation  612  the electrical connection between data communication circuitry (e.g., data communication circuitry  140 ) and the receptacle contacts (e.g., receptacle contacts  174  and  177 ) is optionally disabled, and the electrical connection between audio output circuitry (e.g., audio output circuitry  130 ) and receptacle contacts operable to communicate audio signals from the audio output circuitry (e.g., receptacle contacts  174  and  176 ) is optionally enabled. This operation is similar to operations  414  and  416 , except in this case may be optionally performed as the transmission components of data communication circuitry  140  and audio output circuitry  130  may be naturally isolated from one another. Notwithstanding such operations being indicated as optional in this embodiment, it should be recognized that the corresponding operations previously described with reference to  FIG. 3  (i.e., operations  414  and  416 ) may similarly be optional. 
     In operation  614 , audio is communicated from the host device to the accessory via audio output circuitry (e.g., audio output circuitry  130 ) and the receptacle contacts (e.g., receptacle contacts  174  and  176 ). This operation is similar to operation  418  and thus further description is omitted. 
     Processing may then continue to operation  616  where it is determined whether a disengagement from the plug connector is detected. This operation is similar to operation  420  and thus further description is omitted. When it is determined that the audio plug has not been removed from the receptacle connector, processing may return to operation  616  where the host device  100  continues to monitor for removal of the audio plug. Otherwise, processing may return to operation  602  where the host device  100  optionally disables the electrical connection between the audio output circuitry and receptacle contacts and re-enables the electrical connection between the data communication circuitry and receptacle contacts. 
     It should be appreciated that the specific operations illustrated in  FIG. 10  provide a particular process of a host device for selectively establishing data communication or audio communication over an audio plug having a split-ring contact according to an embodiment. The various operations described with reference to  FIG. 10  may be implemented at and performed by one or more of a variety of electronic devices or components described herein, such as host device  100 . Other sequences of operations may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the operations outlined above in a different order. Moreover, the individual operations illustrated in  FIG. 10  may include multiple sub-operations that may be performed in various sequences as appropriate to the individual operations. Furthermore, additional operations may be added or existing operations removed depending on the particular applications. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives. 
     In addition to processes for a host device determining whether to engage in audio or data communication with an accessory coupled to an audio having a split-ring contact being disclosed, some embodiments are also directed to processes for operating an accessory (e.g., a debug tool) to communicate data over contacts of a split-ring audio plug. In such embodiments, the accessory may first indicate to the host device that it is an accessory desiring to communicate data. In the embodiments described herein, the accessory does this by setting a voltage of one of its contacts (e.g., the tip contact or a contact forming a spit-ring contact of the audio plug) high or by sending some particular string of data over one or more of those contacts. If the accessory receives a response comprising some data communication, then the accessory may determine that the host device has properly identified the accessory as being a data communication accessory. However, if the accessory does not receive such a response, then the accessory may determine that the host has not yet recognized the accessory as being a data communication accessory and thus may not be in a state suitable for data communications. Accordingly, the accessory may again attempt to notify the host device that it is an accessory operable to engage in data communication and may continue to do so until it receives a suitable response from the host device. 
     Turning to the figures,  FIG. 11  illustrates a process  650  of an accessory for selectively establishing data communication over an audio plug having a split-ring contact according to an embodiment. While described with reference to  FIGS. 1 through 10 , it should be recognized that embodiments are not so limited. 
     In operation  652  a signal is output via one of a plurality of contacts of a plug connector shaped like an audio plug and including at least one split-ring contact. For example, data communication circuitry  320  may output a voltage or other signal (such as a sequence of bits) to ring contact  224  of audio plug  200  via the conductive element  240 , or one or more contacts forming a split-ring contact, such as to contact  506  via conductive element  242 . Such signal may be generated and communicated by accessory  300  to indicate to host device  100  that accessory  300  desires to engage in data communication via the audio plug  200 . 
     In operation  654  it is determined whether a response is received over one of the contact of the plug connector from the electronic device. For example, data communication circuitry  320  may monitor contact  506  of split-ring contact  502  to determine whether any voltage or other signal (e.g., a handshake signal) is received at the contact  506 . If it is determined that a response is not received within a particular time period, then processing may return to operation  652  where the accessory again (or continues to) output a signal via one of a plurality of contacts of a plug connector shaped like an audio plug. Otherwise, processing may continue to operation  656 . 
     In operation  656  data communication is established over contacts of the plug connector including a split-ring contact of the plug connector. For example, data communication circuitry  320  may communicate data to host device  100  via tip contact  222  and conductive element  240 , where such data is received via receptacle contact  174  of host device  100 . Data communication circuitry  320  may receive data from host device  100  via contact  506  of split-ring contact  502  and conductive element  242 , where such data is communicated via receptacle contact  177  of host device  100 . 
     In operation  658  accessory  300  may determine whether removal of the plug connector (e.g., audio plug  200 ) from the electronic device (e.g., receptacle  100  of host device  100 ) has been detected. This operation is similar to operation  458 , thus further description is omitted. When it is determined that the audio plug has not been removed from the receptacle connector, processing may return to operation  658  where the accessory  300  continues to monitor for removal of the audio plug. Otherwise, processing may return to operation  652  where the accessory again outputs a signal via one of a plurality of contacts of a plug connector shaped like an audio plug. 
     It should be appreciated that the specific operations illustrated in  FIG. 11  provide a particular process of an accessory for selectively establishing data communication over an audio plug according to an embodiment. The various operations described with reference to  FIG. 11  may be implemented at and performed by one or more of a variety of electronic devices or components described herein, such as accessory  300 . Other sequences of operations may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the operations outlined above in a different order. Moreover, the individual operations illustrated in  FIG. 11  may include multiple sub-operations that may be performed in various sequences as appropriate to the individual operations. Furthermore, additional operations may be added or existing operations removed depending on the particular applications. For example, in some embodiments the accessory may not output a signal via one of its contacts, but may output a signal wirelessly or using some other communication medium. Further, the accessory need not establish only data communications via a split-ring contact, but may also or alternatively establish audio communications over its contacts where one or more of the audio and data communications uses at least one contact forming the split-ring contact. One of ordinary skill in the art would recognize and appreciate many variations, modifications, and alternatives. 
     As described with reference to  FIG. 9 , in some embodiments the split-ring plug connector may not include a keying element  509 . In such embodiments the split-ring plug connector may rotate (or, in the case of non-circular plugs, be arranged in different orientations) in the receptacle connector. It is possible that the plug connector may be oriented in the receptacle such that one or more insulation elements (e.g., insulation element  508 ) lands on (or otherwise contacts) one or more receptacle contacts (e.g., one or more of receptacle contacts  174 ,  176 , and  178 ). In some embodiments, redundant receptacle contacts may be provided and arranged so as to reduce or eliminate this possibility. 
       FIG. 12  illustrates a cross-sectional view of a split-ring plug connector  700  similar to that described with reference to  FIGS. 5A, 5B, and 8A through 8C , and includes a first contact  504  arranged opposite a second contact  506  whereby those contacts are electrically isolated from one another via insulation elements  508  and  510 . In this particular example the insulation elements are arranged at 180 degrees with respect to one another and have a radial width W. To reduce the likelihood of receptacle contacts contacting the insulation elements  508  and/or  510  and consequently being non-functional, at least two receptacle contacts may be included in the receptacle whereby those two receptacle contacts are arranged within the receptacle such that in any given plug orientation at least one of the receptacle contacts is in contact with either the first contact  504  or the second contact  506 . 
       FIG. 13A  illustrates a cross-sectional view of a receptacle  170  having redundant receptacle contacts according to a first embodiment. In this embodiment, receptacle  170  includes a cavity  172  as previously discussed with reference to  FIG. 1 . Receptacle  170  also includes first receptacle contact  173   a  and second receptacle contact  173   b . Receptacle contacts  173   a  and  173   b  are arranged at an angle less than 180 degrees from one another. The angle may depend on the maximum width W of insulation elements  508  and  510  and is at an angle less than 180 degrees such that, if the plug  700  and receptacle  170  were oriented such that the first receptacle contact  173   a  were in contact with insulation element  510 , the second receptacle contact  173   b  would not be in contact with insulation element  508  but rather would be in contact with one of first contact  504  and second contact  506 . In such a case, regardless of the orientation, at least one of contacts  504  and contacts  506  will be in electrical contact with at least one of receptacle contacts  173   a  and  173   b.    
       FIG. 13B  illustrates a cross-sectional view of a receptacle  170  having redundant receptacle contacts according to a second embodiment. In this embodiment, receptacle  170  includes a cavity  172  as previously discussed with reference to  FIG. 1 . Receptacle  170  also includes a first receptacle contact  173   a , second receptacle contact  173   b , and third receptacle contact  173   c . Receptacle contacts  173   a  through  173   c  are arranged such that no two contacts are at an angle of 180 degrees from one another, similar to the two receptacle contacts described with reference to  FIG. 13A . In this case, regardless of the orientation, each of contacts  504  and  506  will be in electrical contact with at least one of receptacle contacts  173   a  through  173   c.    
       FIG. 13C  illustrates a cross-sectional view of a receptacle  170  having redundant receptacle contacts according to a third embodiment. In this embodiment, receptacle  170  includes a cavity  172  as previously discussed with reference to  FIG. 1 . Receptacle  170  also includes a first receptacle contact  173   a , second receptacle contact  173   b , third receptacle contact  173   c , and fourth receptacle contact  173   d . Receptacle contacts  173   a  through  173   d  are arranged such that pairs of contacts are at an angle of 180 degrees from one another. In this case, regardless of the orientation, each of plug contacts  504  and  506  will be in electrical contact with at least one of receptacle contacts  173   a  through  173   d.    
     It should be recognized that the split-ring plug connector described with reference to  FIG. 12  and receptacle connectors described with reference to  FIGS. 13A through 13C  are merely examples and not intended to limit the scope of the embodiments described herein. For example, the receptacle contacts need not have the exact angular dimensions as illustrated in  FIGS. 13A through 13C , but rather may have other angular dimensions such that at least one of the receptacle contacts is in electrical contact with at least one of the split-ring contacts regardless of the orientation of the plug connector with respect to the receptacle connector. Further, embodiments are not limited to split-ring plug connectors having only two contacts forming the split-ring, but may similarly include spilt-ring plug connectors having more than two contacts forming the split-ring. 
     For example,  FIG. 14  illustrates a cross-sectional view of a split-ring plug connector  750  similar to that described with reference to  FIGS. 6A and 6B , and includes a first contact  534 , a second contact  536 , and a third contact  538 , electrically insulated from one another via first insulation element  540 , second insulation element  542 , and third insulation element  544 . In this particular example the insulation elements are arranged at 120 degrees with respect to one another and have a radial width W. To reduce the likelihood of receptacle contacts contacting the insulation elements  540 ,  542 , and/or  544  and consequently being non-functional, at least two receptacle contacts may be included in the receptacle whereby those two receptacle contacts are arranged within the receptacle such that in any given plug orientation at least one of the receptacle contacts is in contact with either the first contact  534 , the second contact  536 , or the third contact  538 . 
       FIG. 15A  illustrates a cross-sectional view of a receptacle  170  having redundant receptacle contacts according to a fourth embodiment. In this embodiment, receptacle  170  includes a cavity  172  as previously discussed with reference to  FIG. 1 . Receptacle  170  also includes first receptacle contact  173   a  and second receptacle contact  173   b . Receptacle contacts  173   a  and  173   b  are arranged at an angle of 180 degrees from one another. The angle may depend on the maximum width W of insulation elements  540 ,  542 , and  544 , and is at an angle different than any of the angles between pairs of insulation elements  540 ,  542 , and  544 , such that if the plug  750  and receptacle  170  were oriented such that the first receptacle contact  173   a  were in contact with insulation element  544 , the second receptacle contact  173   b  would not be in contact with either insulation element  540  or  542  but rather would be in contact with second contact  536 . In such a case, regardless of the orientation, at least one of plug contacts  534 ,  536 , and  538  will be in electrical contact with at least one of receptacle contacts  173   a  and  173   b.    
       FIG. 15B  illustrates a cross-sectional view of a receptacle  170  having redundant receptacle contacts according to a fifth embodiment. In this embodiment, receptacle  170  includes a cavity  172  as previously discussed with reference to  FIG. 1 . Receptacle  170  also includes a first receptacle contact  173   a , second receptacle contact  173   b , and third receptacle contact  173   c . Receptacle contacts  173   a  and  173   c  are arranged at 180 degrees from one another, and are each arranged at 90 degrees from receptacle contact  173   b . As a result, none of the receptacle contacts are arranged at the 120 degrees angles used by the insulation elements of the plug connector. In this case, regardless of the orientation, at least two of the plug contacts  534 ,  536 , and  538  will be in electrical contact with at least two of receptacle contacts  173   a  through  173   c.    
       FIG. 15C  illustrates a cross-sectional view of a receptacle  170  having redundant receptacle contacts according to a sixth embodiment. In this embodiment, receptacle  170  includes a cavity  172  as previously discussed with reference to  FIG. 1 . Receptacle  170  also includes a first receptacle contact  173   a , second receptacle contact  173   b , third receptacle contact  173   c , and fourth receptacle contact  173   d . Receptacle contacts  173   a  through  173   d  are arranged such that pairs of contacts are at an angle of 180 degrees from one another. In this case, regardless of the orientation, each of plug contacts  534 ,  536 , and  538  will be in electrical contact with at least one of receptacle contacts  173   a  through  173   d.    
     It should be recognized that the split-ring plug connector described with reference to  FIG. 14  and receptacle connectors described with reference to  FIGS. 15A through 15C  are merely examples and not intended to limit the scope of the embodiments described herein. For example, the receptacle contacts need not have the exact angular dimensions as illustrated in  FIGS. 15A through 15C , but rather may have other angular dimensions such that at least one of the receptacle contacts is in electrical contact with at least one of the split-ring contacts regardless of the orientation of the plug connector with respect to the receptacle connector. Further, embodiments are not limited to split-ring plug connectors having only two or three contacts forming the split-ring at equal angles, but may similarly include spilt-ring plug connectors having more than two or three contacts forming the split-ring at the same or different angles. 
     In some embodiments, particularly embodiments where the plug orientation may change with respect to the receptacle, and a particular plug contact may then electrically contact a different receptacle contact depending on the orientation, the host device  100  may include orientation detection circuitry operable to detect the orientation of the plug. Such circuitry may be implemented in existing circuitry already described (e.g., plug detection circuitry  120 ), processor  110 , or in circuitry separate from that already described. The orientation detection circuitry may be coupled to one or more receptacle contacts such that it can communicate and/or receive signals via the receptacle contacts. The orientation detection circuitry may then determine the orientation of the plug connector based on signals communicated and/or received over different receptacle contacts. Some particular techniques for detecting orientation of a plug connector are described in U.S. patent application Ser. No. 13/232,989, filed Sep. 14, 2011, U.S. patent application Ser. No. 13/232,978, filed Sep. 14, 2011, and U.S. patent application Ser. No. 13/607,550, filed Sep. 7, 2012, all of which are hereby incorporated by reference in their entirety for all purposes. 
     Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. 
     Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above, and/or a combination thereof. 
     Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. 
     Furthermore, embodiments may be implemented by hardware, software, scripting languages, firmware, middleware, microcode, hardware description languages, and/or any combination thereof. When implemented in software, firmware, middleware, scripting language, and/or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as a storage medium. A code segment or machine-executable instruction may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a script, a class, or any combination of instructions, data structures, and/or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, and/or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. 
     While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the present teachings.

Metadata:
Filing Date: 20130315
Publication Date: 20160906
Grant Date: 20160906
Priority Date: 20130315
Inventors: VILLARREAL CESAR LOZANO
LU RUENJOU
AMINI MAHMOUD R.
ZWEIG JONATHAN M.
BREECE, III DAVID C.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F16/60", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F13/20", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F13/102", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R24/58", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F13/4068", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R24/86", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R2107/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R24/86", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R24/58", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R2107/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F17/3074", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 51531398