PATENT DOCUMENT

Publication Number: US-8648501-B2
Application Number: US-201313797850-A
Country: US
Kind Code: B2

Title: Systems and methods for providing protection circuitry to selectively handle multiple cable-types through the same port

Abstract:
This is generally directed to providing protection circuitry to selectively handle power-providing cables and headset cables that can couple to the same port of an electronic device. In some embodiments, the device can include a Headset Rx chip to communicate with the headset cable and a Power Rx chip to communicate with the power-providing cable. As the Headset Rx chip and the Power Rx chip can be coupled to the same contact of the device&#39;s port, these chips may prevent one another from operating correctly or may damage one another. Accordingly, in some embodiments, it can be determined whether a headset cable or a power-providing cable is coupled to the device. When a headset cable is coupled to the device, the protection circuitry can disconnect the Power Rx chip. Similarly, when a power-providing cable is coupled to the device, the protection circuitry can disconnect the Headset Rx chip.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a port, the port comprising a first contact and a second contact; 
 a processor coupled to the first contact, wherein the processor analyzes the first contact to determine when a cable having a circuit is connected at the port; 
 a power control circuit coupled to the second contact, the power control circuit to receive a disconnect signal from the processor; 
 a non-power providing cable receive circuit (“Headset Rx”) coupled to the second contact, wherein the processor instructs the Headset Rx to attempt to authenticate the cable circuit, and the Headset Rx authenticates the cable circuit when the cable circuit is a non-power providing cable transmit circuit; and 
 a power-providing cable receive circuit (“Power Rx”) coupled between the power control circuit and the processor, wherein the processor instructs the Power Rx to attempt to authenticate the cable circuit, and the Power Rx authenticates the cable circuit when the cable circuit is a power providing cable transmit circuit; 
 wherein when the power control circuit receives a disconnect signal from the processor, the power control circuit disconnects the Power Rx from the second contact, otherwise the Power Rx is coupled to the second contact through the power control circuit. 
 
     
     
       2. The electronic device of  claim 1  further comprising:
 a headset control circuit coupled between the second contact and the Headset Rx, the headset control circuit to receive a second disconnect signal from the processor. 
 
     
     
       3. The electronic device of  claim 2  wherein when the headset control circuit receives a disconnect signal from the processor, the headset control circuit disconnects the Headset Rx from the second contact, otherwise the Headset Rx is coupled to the second contact through the headset control circuit. 
     
     
       4. The electronic device of  claim 1  wherein the Power Rx authenticates the cable circuit when the Power Rx receives a series of pulses from the cable circuit. 
     
     
       5. The electronic device of  claim 1  wherein the Headset Rx authenticates the cable circuit when the Headset Rx receives a sine wave having an amplitude in a first range and a first frequency in a second range from the cable circuit. 
     
     
       6. The electronic device of  claim 1  wherein when the power for the electronic device is off when the cable having a circuit is connected at the port, the Power Rx attempts to authenticate the cable circuit before the Headset Rx attempts to authenticate the cable circuit. 
     
     
       7. The electronic device of  claim 1  wherein when the power for the electronic device is on when the cable having a circuit is connected at the port, the Headset Rx attempts to authenticate the cable circuit before the Power Rx attempts to authenticate the cable circuit. 
     
     
       8. An electronic device comprising:
 a port, the port comprising a first contact and a second contact; 
 a processor coupled to the first contact, wherein the processor analyzes the first contact to determine when a cable having a circuit is connected at the port; 
 a non-power providing cable receive circuit (“Headset Rx”) coupled between the second contact and the processor, wherein the processor instructs the Headset Rx to attempt to authenticate the cable circuit, and the Headset Rx authenticates the cable circuit when the cable circuit is a non-power providing cable transmit circuit; and 
 a power-providing cable receive circuit (“Power Rx”) coupled between the power control circuit and the processor, wherein the processor instructs the Power Rx to attempt to authenticate the cable circuit, and the Power Rx authenticates the cable circuit when the cable circuit is a power providing cable transmit circuit; 
 wherein when the Headset Rx authenticates the cable circuit, the processor disconnects the Power Rx from the second contact. 
 
     
     
       9. The electronic device of  claim 8  further comprising:
 a power control circuit coupled to the second contact, the power control circuit to receive a disconnect signal from the processor. 
 
     
     
       10. The electronic device of  claim 9  wherein when the power control circuit receives a disconnect signal from the processor, the power control circuit disconnects the Power Rx from the second contact, otherwise the Power Rx is coupled to the second contact through the power control circuit. 
     
     
       11. The electronic device of  claim 8  further comprising:
 a headset control circuit coupled between the second contact and the Headset Rx, the headset control circuit to receive a second disconnect signal from the processor. 
 
     
     
       12. The electronic device of  claim 11  wherein when the headset control circuit receives a disconnect signal from the processor, the headset control circuit disconnects the Headset Rx from the second contact, otherwise the Headset Rx is coupled to the second contact through the headset control circuit. 
     
     
       13. The electronic device of  claim 8  wherein the Power Rx authenticates the cable circuit when the Power Rx receives a series of pulses from the cable circuit. 
     
     
       14. The electronic device of  claim 8  wherein the Headset Rx authenticates the cable circuit when the Headset Rx receives a sine wave having an amplitude in a first range and a first frequency in a second range from the cable circuit. 
     
     
       15. The electronic device of  claim 8  wherein when the power for the electronic device is off when the cable having a circuit is connected at the port, the Power Rx attempts to authenticate the cable circuit before the Headset Rx attempts to authenticate the cable circuit. 
     
     
       16. The electronic device of  claim 8  wherein when the power for the electronic device is on when the cable having a circuit is connected at the port, the Headset Rx attempts to authenticate the cable circuit before the Power Rx attempts to authenticate the cable circuit.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/477,547, filed Jun. 3, 2009, which is a nonprovisional of 61/158,565 filed Mar. 9, 2009, which are incorporated by reference. 
    
    
     BACKGROUND 
     This relates to systems and methods for providing protection circuitry to selectively handle multiple cable-types through the same port of an electronic device. In particular, this relates to systems and methods for providing protection circuitry to selectively handle power-providing cables and non-power providing cables through the same port of an electronic device. 
     As technology becomes more sophisticated, electronic devices tend to get smaller. For example, electronic devices such as laptops, digital media players (e.g., an iPod™ made available by Apple Inc. of Cupertino, Calif.), cellular telephones, personal data assistants (“PDAs”), handheld gaming devices, and personal e-mail devices (e.g., a Blackberry™ made available by Research in Motion of Waterloo, Ontario) are getting smaller in size. This is often the case even though the internal circuitry and capabilities of these smaller electronic devices may be more advanced than their larger and older counterparts. As electronic devices become smaller in size, it can become necessary to conserve space on the electronic device. As one example of a way to conserve space, the number of ports available for coupling the electronic device to various cables can be reduced. 
     SUMMARY 
     Systems and methods for providing protection circuitry to selectively handle multiple cable-types through the same port of an electronic device are provided. In particular, systems and methods for providing protection circuitry to selectively handle power-providing cables and non-power providing cables that can couple to the same port of an electronic device are provided. 
     In some embodiments, a power-providing cable (e.g., a USB cable, or any other suitable power-providing cable) and a non-power providing cable (e.g., headphones, microphones, a user control interface, such as a remote controller that can include at least one user input, speakers, headset, or any other suitable non-power providing cable) can couple to the same port on an electronic device. The power-providing cable can include a Power Cable Transmit Chip (“Power Tx”) that can communicate with a Power Cable Receive Chip (“Power Rx”) of the electronic device. Similarly, the non-power providing cable can include a Headset Cable Transmit Chip (“Headset Tx”) that can communicate with a Headset Cable Receive Chip (“Headset Rx”) of the electronic device. In some embodiments, the Power Rx can communicate with the Power Tx to authenticate the power-providing cable and the Headset Rx can communicate with the Headset Tx to authenticate the non-power providing cable. 
     In some embodiments, the same contact of the port can be used to receive a power signal (“PWR”) when a power-providing cable is coupled to the electronic device and to receive user input signals (“INPUT”) when a non-power providing cable is coupled to the electronic device. In some embodiments, the Power Rx and the Headset Rx of the electronic device can also be coupled to this contact. However, in some cases the Power Rx can prevent the Headset Rx from operating correctly or can be damaging to the Headset Rx. For example, if a non-power providing cable is coupled to the electronic device, the input capacitance of the Power Rx can prevent the Headset Rx from properly authenticating the Headset Tx, or leakage current from the Power Rx can damage user input signals received from the non-power providing cable. As another example, if a power-providing cable is coupled to the electronic device, the PWR signal can cause electrical shorts or damage the Headset Rx if the Headset Rx does not have proper protection to handle a power signal. 
     Accordingly, in some embodiments, it can be determined whether a power-providing cable or a non-power providing cable is coupled to the electronic device. If a non-power providing cable is coupled to the electronic device, the Power Rx chip can be disconnected to prevent it from possibly harming operation of the Headset Rx chip. Similarly, if a power-providing cable is coupled to the electronic device, the Headset Rx chip can be disconnected to prevent it from possibly being harmed by the PWR signal. 
     In some embodiments, the type of cable that is coupled to the electronic device can be determined by attempting to authenticate a particular type of cable. For example, the Power Rx chip can be disconnected and the Headset Rx chip can attempt to authenticate a Headset Tx chip. If a Headset Tx chip is successfully authenticated, the current settings can be maintained and the Power Rx chip can remain disconnected. If a Headset Tx chip is not successfully authenticated, the Power Rx chip can be reconnected and the Headset Rx chip can be disconnected. The Power Rx chip can then attempt to authenticate a Power Tx chip. If a Power Tx chip is authenticated, the current settings can be maintained and the Headset Rx chip can remain disconnected. If a Power Tx chip is not authenticated, the system can alternate between attempting to authenticate a Headset Tx chip and a Power Tx chip until one of them is successfully authenticated. 
     In some embodiments, the type of cable that is coupled to the electronic device can be determined by identifying whether a PWR signal is received. If a PWR signal is received, this can indicate that a power-providing cable is coupled to the electronic device. Accordingly, the Headset Rx chip can be disconnected. If a PWR signal is not received, however, this can indicate that a non-power providing cable is coupled to the electronic device. In this scenario, the Power Rx chip can be disconnected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
         FIGS. 1 and 2  show illustrative systems including power-providing cables in accordance with some embodiments of the invention; 
         FIGS. 3 and 4  show illustrative systems including non-power providing cables in accordance with some embodiments of invention; 
         FIG. 5  shows an illustrative power-providing cable and non-power providing cable that can couple to the same communication port in accordance with some embodiments of the invention; 
         FIG. 6  shows a schematic view of a system for coupling multiple cable-types to the same communication port in accordance with some embodiments of the invention; 
         FIG. 7  shows a schematic view of a system including protection circuitry for coupling multiple cable-types to the same communication port in accordance with some embodiments of the invention; and 
         FIGS. 8 and 9  show illustrative processes for selectively handling multiple cable-types through the same communication port in accordance with some embodiments of the invention. 
     
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     Electronic devices can couple to various types of cables through various types of ports. For example, electronic devices can couple to data and power-providing cables such as universal serial bus (“USB”) cables or any other suitable power-providing cables. As another example, electronic devices can couple to non-power providing cables such as headphones, microphones, user control interfaces (e.g., remote controllers that can include at least one user input), speakers, or any other suitable non-power providing cables. The cables can couple to the electronic device through any suitable port such as, for example, a multi-contact connector port (e.g., a 30-pin connector port), a Firewire port, a USB port (e.g., a Type A port, a Type B port, Mini-A port, or a Mini-B port), a PS/2 port, an audio jack (e.g., a 3.5 millimeter or 2.5 millimeter jack), an Ethernet port, a telephone modem port, or any other suitable port. 
       FIG. 1  shows an illustrative system  100  that can include power-providing cable  102 . Power-providing cable  102  can couple to electronic device  104  through, for example, port  106  of electronic device  104 . In some embodiments, in addition to providing power, power-providing cable  102  can additionally communicate data to electronic device  104 . For example, in some embodiments, power-providing cable  102  can include a USB cable that is capable of providing both data and power to electronic device  104 . Electronic device  104  can include any suitable device that can couple to power-providing cable  102  such as, for example, a laptop computer, a desktop computer, a digital media player (e.g., an iPod™), a cellular telephone, a PDA, a handheld gaming device, a personal e-mail device (e.g., a Blackberry™), or any other suitable electronic device. Port  106  can include any port suitable to receive power-providing cable  102  such as, for example a USB Type-A port, a USB Type-B port, a USB Mini-A port, a USB Mini-B port, or any other suitable port. 
     In some embodiments, power-providing cable  102  can communicate four signals as inputs, outputs, or both to electronic device  104 . For example, power-providing cable  102  can communicate signals such as ground (e.g., GND), power (e.g., PWR), and two data lines (e.g., D+ and D− ). Power-providing cable  102  may, for example, include four contacts, where each of the four signals can be provided to electronic device  104  through a separate contact. 
     In some embodiments, the power signals, the data signals, or both (e.g., the PWR signal, D+ and D− signals, or both), can be supplied to electronic device  104  by a friendly device that is coupled to a plug on the other end of power-providing cable  102 . For example,  FIG. 2  shows system  200  that can include power-providing cable  202 . Plug  208  of power-providing cable  202  can be coupled to electronic device  204  at port  206  and plug  210  of power-providing cable  202  can be coupled to friendly device  212 . Although power-providing cable  202  is illustrated in  FIG. 2  as having two plugs (e.g., plug  208  and plug  210 ), one skilled in the art can appreciate that in some embodiments power-providing cable  202  may split, and thus may include three or more plugs. Friendly device  212  can be any suitable device for supplying power, data, or both to electronic device  204  such as, for example, a desktop computer, a laptop computer, or any other suitable friendly device. In some embodiments, rather than coupling plug  210  to friendly device  212 , power can be provided to electronic device  204  by coupling plug  210  to a power supply such as, for example, a wall socket or a battery. 
     In some embodiments, power-providing cable  202  and electronic device  204  can each include one or more integrated circuits to allow them to communicate with one other. For example, power-providing cable  202  can include power-providing cable transmit chip (“Power Tx”)  230  and electronic device  204  can include power-providing cable receive chip (“Power Rx”)  232 . Although Power Tx  230  is illustrated as being located in the middle of power-providing cable  202 , one skilled in the art can appreciate that Power Tx  230  may alternatively be located at either end (e.g., within plug  208  or plug  210 ) or anywhere along the length of power-providing cable  202 . 
     In some embodiments, Power Tx  230  and Power Rx  232  can communicate in order to identify or authenticate one another. For example, Power Rx  232  can communicate with Power Tx  230  to determine the characteristics or identity of power-providing cable  202 , of a friendly device that is coupled to power-providing cable  202  (e.g., friendly device  212 ), of a power supply that is coupled to power-providing cable  202 , or any combination of the above. For example, Power Rx  232  can determine the characteristics of the power being supplied, the characteristics of the data being supplied, the operating environment of the friendly device, the type of friendly device, or any other suitable characteristics. Power Tx  230  can fail to authenticate if, for example, it is determined that the cable, friendly device, or power supply is not appropriate for use with electronic device  204 . For example, the friendly device or power supply may be attempting to provide too much power, an improperly regulated power supply signal, or an otherwise potentially harmful power signal to electronic device  204 . As another example, the friendly device may be identified as a device that is not approved for use with electronic device  204  (e.g., the friendly device may be manufactured by a non-approved third party vendor). In this case, when Power Tx  230  fails to authenticate, Power Rx  232  can prevent power, data, or both from being transmitted and/or received by electronic device  204  through power-providing cable  202 . 
     If Power Tx  230  does successfully authenticate, Power Rx  232  may, for example, allow power, data, or both to be transmitted and/or received from power-providing cable  202 . As another example, Power Rx  232  may instruct Power Tx  230  to regulate the power by providing it in a certain manner (e.g., by providing the power at a certain intensity, voltage, or current). 
     In some embodiments, Power Tx  230  and Power Rx  232  can authenticate one another through the PWR signal. For example, Power Tx  230  may provide a series of pulses through the PWR signal to Power Rx  232 . If an appropriate series of pulses are received by Power Rx  232  (e.g., if a PWR signal of the appropriate frequency, amplitude, portraying the appropriate current spikes, or any combination of the above is received), Power Rx  232  may then authenticate Power Tx  230 . 
     As mentioned above, in some embodiments an electronic device can be coupled to a non-power providing cable such as, for example, a cable associated with headphones, a microphone, a user control interface (e.g., a remote controller that can include at least one user input), speakers, a headset, or any other suitable non-power providing cable. For example,  FIG. 3  shows non-power providing cable or headset cable  302  that can couple to electronic device  304  through port  306  of electronic device  304 . As used herein, the terms “headset” and “headset cable” are used throughout the disclosure for simplicity and clarity, but one skilled in the art can appreciate that any suitable non-power providing cable may alternatively be used without departing from the scope of the invention. 
     Similar to electronic device  104  of  FIG. 1 , electronic device  304  can include any suitable electronic device that can couple to headset cable  302  such as, for example, a laptop computer, a desktop computer, a digital media player (e.g., an iPod™), a cellular telephone, a PDA, a handheld gaming device, a personal e-mail device (e.g., a Blackberry™), or any other suitable electronic device. Port  306  can include any port suitable to receive headset cable  302  (e.g., a communications port). 
     In some embodiments, headset cable  302  can include and couple electronic device  304  to, for example, headphones, speakers, a microphone, a user control interface (e.g., a remote controller that can include at least one user input), or any other suitable non-power providing friendly device or item. For example,  FIG. 4  shows headset cable  402  that can couple to electronic device  404  and one or more of left headphone  418 , right headphone  420 , and user control interface  422 . Although  FIG. 4  illustrates headset cable  402  with left headphone  418 , right headphone  420 , and user control interface  422 , one skilled in the art can appreciate that headset cable  402  may include any suitable combination of speakers, headphones, microphones, user inputs, or any other suitable non-power providing devices without departing from the scope of the invention. 
     User control interface  422  can include, for example, one or more buttons, touch screens, click wheels, switches, microphones, or any other suitable user input. In some embodiments, user control interface  422  may function as a remote controller that can allow a user to manipulate the playback of digital media files stored in electronic device  404  by, for example, pausing, stopping, playing, skipping, adjusting the volume, or otherwise suitably manipulating the playback of the files. In some embodiments, user control interface  422  can allow a user to control electronic device  404  by, for example, navigating menus or adjusting settings (e.g., power, volume, screen brightness, or any other suitable setting) of electronic device  404 . In some embodiments, user control interface  422  can function as a microphone that can receive the user&#39;s voice as an input. 
     In some embodiments, headset cable  402  can communicate four signals as inputs, outputs, or both to electronic device  404 . For example, headset cable  402  can communicate signals such as ground (e.g., GND), left headphone output (e.g., LEFT), right headphone output (e.g., RIGHT), and INPUT. In some embodiments, LEFT and RIGHT can alternatively function as any other suitable input, output, or bi-directional data signal. INPUT can include, for example, signals derived from user inputs received through user control interface  422 . In some embodiments, plug  408  of headset cable  402  can include four contacts for communicating each of these four signals to port  406  of electronic device  404 . 
     Similar to power-providing cable  202  and electronic device  204  of  FIG. 2 , headset cable  402  and electronic device  404  can each include one or more integrated circuits to allow them to communicate with one other. For example, headset cable  402  can include a headset cable transmit chip (“Headset Tx”)  440  and electronic device  404  can include a headset cable receive chip (“Headset Rx”)  4442 . Although Headset Tx  440  is illustrated as located in the middle of headset cable  402  in  FIG. 4 , one skilled in the art can appreciate that Headset Tx  440  may alternatively be located in plug  408 , left headphone  418 , right headphone  420 , user control interface  422 , or anywhere along the length of headset cable  402  without departing from the scope of the invention. 
     Also similar to Power Tx  230  and Power Rx  232  of  FIG. 2 , Headset Tx  440  and Headset Rx  442  can communicate in order to identify or authenticate one another. For example, Headset Tx  440  can communicate a series of sine waves or any other suitable signals to Headset Rx  442 . If an appropriate series of sine waves are received by Headset Rx  442  (e.g., if the sine waves are of the appropriate frequency, amplitude, or both), Headset Rx  442  may then authenticate Headset Tx  440 . 
     As described above, an electronic device can couple to various types of power-providing cables and non-power providing cables. These cables can be very different in nature. 
     For example, the cables may provide different types of functionality for the electronic device (e.g., transferring data, providing power, outputting audio, accepting user inputs, or any combination of the above), communicate different types of signals to the electronic device (e.g., GND, PWR, D+, D−, LEFT, RIGHT, or INPUT), and can require different types of ports to couple to the electronic device. Thus, because different ports may be required for each different type of cable, an electronic device may need to include a plurality of different ports in order to allow it to couple to these different cables. These multiple ports can require a substantial amount of space, thus potentially preventing the electronic device from achieving a small and compact design. 
     Accordingly, in some embodiments, a port that can couple to a variety of different cables can be provided. This can allow for an electronic device that can couple to a wide range of cables while requiring a fewer number of ports. In some embodiments, the electronic device may only require one port. This, in turn, may reduce the required size of the electronic device, thus allowing a smaller and more compact electronic device to be designed. 
     For example,  FIG. 5  shows system  500  that can include power-providing cable  502  and headset cable  504 . Similar to headset cable  402  of  FIG. 4 , one skilled in the art can appreciate that any suitable non-power providing cable may alternatively be used instead of headset cable  504  without departing from the scope of the invention. Additionally, similar to power-providing cable  202  of  FIG. 2  and headset cable  402  of  FIG. 4 , power-providing cable  502  can include Power Tx  530  and headset cable  504  can include Headset Tx  540 . 
     Power-providing cable  502  and headset cable  504  can be designed such that they can each couple to the same port  506  of an electronic device  554 . Accordingly, electronic device  554  may only require a single port to allow it to couple to both power-providing cable  502  and headset cable  504 . Although power-providing cable  502 , headset cable  504 , their associated plugs, and port  506  are illustrated in  FIG. 5  as having a particular shape and design (e.g., they are illustrated as similar to a 3.5 millimeter plug and cable), the cables may alternatively include any suitable design, shape, or type of plug that can allow each cable to couple to the same port. For example, the cables can alternatively include a plug that is round in shape (e.g., PS/2), rectangular in shape (e.g., FireWire or USB Type-A), square in shape (e.g., USB Type-B, Ethernet plug, or telephone modem), trapezoidal in shape (e.g., D-Sub), or any other suitable shape or design. 
     As mentioned above, a power-providing cable and a headset cable may each include four contacts that can communicate four signals, although each cable may alternatively include any other suitable number of contacts or signals. For example, power-providing cable  502  can include plug  505  with a D− contact  508 , D+ contact  510 , GND contact  512 , and PWR contact  514 . Each of these contacts of power-providing cable  502  can be separated by an insulating ring  516 . Similarly, headset cable  504  can include a plug  515  with a LEFT contact  518 , RIGHT contact  520 , GND contact  522 , and INPUT contact  524 . Each of these contacts of headset cable  504  can be separated by an insulating ring  526 . 
     Port  506  may similarly contain four contacts (e.g., contacts  558 ,  560 ,  562 , and  564 ) such that, when either plug  505  of power-providing cable  502  or plug  515  of headset cable  504  is inserted into port  506 , the contacts of port  506  and the contacts of the inserted cable may electrically couple to one another. The electrical coupling of the contacts can then allow the appropriate signals to be communicated from the cable, through port  506 , and to other portions of electronic device  554 . For example, depending on whether power-providing cable  502  or headset cable  504  is coupled to port  506 , contact  558  of port  506  can receive the D− signal or the LEFT signal, contact  560  of port  506  can receive the D+ signal or the RIGHT signal, contact  562  of port  506  can receive the GND signal, and contact  564  of port  506  can receive the PWR signal or the INPUT signal. 
       FIG. 6  shows a schematic view of system  600  of an electronic device  654  including a port  606  that can couple multiple power-providing cables and headset cables to the same port. Port  606  can include contact  658 , contact  660 , contact  662 , and contact  664  that may, for example, correspond to contact  558 , contact  560 , contact  562 , and contact  564  of port  506  of  FIG. 5 . Signals communicated through contact  658  (e.g., D− or LEFT) and contact  660  (e.g., D+ or RIGHT) can be coupled to processor  602 . For example, when a power-providing cable is coupled to system  600 , processor  602  may manage the data that is communicated through the D− and D+ signals. As another example, when a headset is coupled to system  600 , processor  602  may control the audio signals that are output through the LEFT and RIGHT signals. Contact  662  can be coupled to GND, and can provide a GND signal for a power-providing cable or a headset cable that is coupled to system  600 . 
     When a power-providing cable is coupled to port  606 , contact  664  can receive a PWR signal from the power-providing cable. Alternatively, when a headset cable is coupled to system  600 , contact  664  can receive an INPUT signal from the headset cable. Before proceeding to processor  602 , the signal received through contact  664  can split and go through Power Rx  632  and Headset Rx  642 . These chips, Power Rx  632  and Headset Rx  642 , can correspond, respectively, to chips such as Power Rx  232  of  FIG. 2  and Headset Rx  442  of  FIG. 4 . Accordingly, when a power-providing cable is coupled to system  600 , the Power Tx chip of this cable can communicate with Power Rx  632  through the PWR signal to authenticate the power-providing cable. Similarly, when a headset cable is coupled to system  600 , the Headset Tx chip of this cable can communicate with Headset Rx  642  through the INPUT signal to authenticate the headset cable. 
     In some embodiments, rather than having both Headset Rx  642  and Power Rx  632  coupled to contact  664 , one of these chips may be disconnected when a cable has been coupled to system  600 . Allowing both the Headset Rx  642  and Power Rx  632  to remain coupled to contact  664  may prevent a successful authentication of a cable or allow an unnecessary PWR signal to potentially damage the system. 
     For example, Power Rx  632  may include a particular amount of capacitance at its input. If Power Rx  632 , and thus its input capacitance, is not disconnected from Headset Rx  642 , this input capacitance may prevent successful authentication of a headset cable. This can occur since a Headset Tx chip in a headset cable may transmit a series of sine waves to Headset Rx  642  in an attempt to authenticate itself. The input capacitance or Power Rx  632  may, however, detrimentally cause the transmitted sine wave to be absorbed or altered. Thus, although the Headset Tx chip may have originally transmitted an appropriate sine wave, Headset Rx  642  may instead receive an altered, inappropriate sine wave and thus may not authenticate the Headset Tx chip. 
     As another example, Power Rx  632  may have leakage current that can prevent user inputs received from a headset cable (e.g., received from user control interface  422  of  FIG. 4 ) from functioning properly. Accordingly, when a headset cable is coupled to system  600 , Power Rx  632  can be disconnected from contact  664  to prevent this leakage current from potentially harming the operation of the headset cable. 
     As another example, when a power-providing cable is coupled to system  600 , a PWR signal can be provided to both Power Rx  632  and Headset Rx  642 . However, if Headset Rx  642  does not have any suitable internal protection to properly handle the PWR signal, Headset Rx  642  may be damaged by the PWR signal. For example, the PWR signal may cause damaging shorts or otherwise harm Headset Rx  642 . Accordingly, in some embodiments, Headset Rx  642  can be disconnected from contact  664  when a power-providing cable is coupled to system  600 . 
       FIG. 7  shows a schematic view of system  700  for electronic device  754  that can include port  706 . System  700  can include protection circuitry such as, for example, Power Control  750  and Headset Control  760 . Power Control  750  may disconnect Power Rx  732  from contact  764  when a headset cable is coupled to system  700 . Similarly, Headset Control  760  may disconnect Headset Rx  742  from contact  764  when a power-providing cable is coupled to system  700 . For example, when a headset cable is coupled to system  700 , processor  702  can send instructions to Power Control  750  through Control Line  752  for directing Power Control  750  to disconnect Power Rx  732 . Similarly, when a power-providing cable is coupled to system  700 , processor  702  can send instructions to Headset Control  760  through Control Line  762  for directing Headset Control  760  to disconnect Headset Rx  742 . 
     In some embodiments, if Headset Rx  742  has internal shielding to protect it from a PWR signal, Headset Control  760  may not be included in system  700 . In particular, in some embodiments, system  700  can remove one or more of the components illustrated in  FIG. 7 , can include other components not illustrated in  FIG. 7 , can include several instances of the components shown in  FIG. 7 , or may rearrange various electrical connections or contacts without departing from the scope of the invention. For example, additional circuitry can be added or contact numbers may be rearranged without departing from the scope of the invention. 
     In some embodiments, system  700  can determine when a cable has been coupled to system  700 . For example, processor  702  can analyze contact  758  or contact  760  to determine if a cable is coupled to system  700 . When it has been determined that a cable is connected to system  700 , system  700  can then determine what type of cable has been connected. Once the cable-type has been determined, system  700  can determine whether to disconnect Power Rx  732  or Headset RX  742 . 
     In some embodiments, the cable-type can be determined by attempting to authenticate a particular transmit chip. For example, system  700  can “assume” (e.g., through software, an algorithm, or both) that a headset cable is coupled to the system and attempt to authenticate a Headset Tx chip. System  700  can thus direct Power Control  750  to disconnect Power Rx  732 , and then attempt to authenticate a Headset Tx chip with Headset Rx  742 . If a Headset Tx chip successfully authenticates, the system can remain with its current settings (e.g., can remain with Power Rx  732  disconnected). If, however, a Headset Tx chip does not successfully authenticate, system  700  can then “assume” (e.g., through software, an algorithm, or both) that a power-providing cable is coupled to the system. Accordingly, system  700  can reconnect Power Rx  732  and then disconnect Headset Rx  742 . System  700  can then attempt to authenticate a Power Tx chip with Power Rx  732 . In some embodiments, system  700  can continue to alternate between attempting to authenticate a Headset Tx chip and a Power Tx chip until a successful authentication is completed. Various ways in which a system can determine a cable-type by attempting to authenticate a Power Tx or Headset Tx chip is discussed in more detail with respect to  FIG. 8  and in the descriptions to follow. 
     In some embodiments, the cable-type can be determined by identifying whether or not a PWR signal is present. If a PWR signal is present, the system can determine that a power-providing cable is coupled to the system. If a PWR signal is not present, the system can then determine that a headset cable is coupled to the system. Various ways in which a system can determine a cable-type by identifying whether a PWR signal is present is discussed in more detail with respect to  FIG. 9  and in the descriptions to follow. 
       FIG. 8  shows process  800  that can identify what cable-type is coupled to a system by attempting to authenticate a Power Tx chip or a Headset Tx Chip. 
     Process  800  can begin at step  802 . At step  804 , process  800  can determine whether a cable is coupled to the system. For example, as described above, a processor can analyze contacts of a port (e.g., contact  758  or contact  760  of  FIG. 7 ) to determine whether a cable is coupled to that port. If a cable is not coupled to the system, process  800  can continue to repeat steps  802  and  804  until a cable is coupled to the system. 
     When a cable is coupled to the system, process  800  can disconnect the Power Rx chip (e.g., Power Rx  732  of  FIG. 7 ) at step  806 . For example, a processor can supply a signal through a control line (e.g., Control Line  752  of  FIG. 7 ) to a Power Rx Control System (e.g., Power Control  750  of  FIG. 7 ). The signal supplied by the processor can then direct the Power Rx Control System to disconnect the Power Rx chip from the system. Accordingly, the Power Rx chip may then be disabled from preventing the successful authentication of a Headset Tx chip or from creating undesirable leakage current. 
     At step  808 , process  800  can attempt to authenticate a Headset Tx chip (e.g., Headset Tx  540  of  FIG. 5 ). For example, a Headset Rx chip of the system (e.g., Headset Rx  742  of  FIG. 7 ) can sense if a Headset Tx chip is attempting to send an authenticating signal such as, for example, a series of sine waves. The Headset Rx chip can then analyze any signals that are received. If a received signal includes a series of appropriate sine waves (e.g., a series of sine waves of the appropriate frequency, amplitude, or any combination of the above) the Headset Rx chip can authenticate the Headset Tx chip. If the received signal does not include a series of appropriate sine waves, a Headset Tx chip may not be authenticated. 
     If a Headset Tx chip is authenticated, the system can keep its current settings at step  810 . Generally, successfully authenticating a Headset Tx chip can indicate that a headset cable (or other appropriate non-power providing cable) has been coupled to the system. Accordingly, by keeping its current settings, process  800  can keep a Power Rx chip disconnected from the system, thus preventing undesirable input capacitance or leakage current from the Power Rx chip from harming the operation of the headset cable and Headset Rx chip. In some embodiments, successfully authenticating a Headset Tx chip can also indicate that the headset cable is appropriate for use with the system (e.g., the headset cable is not damaging to the system, or was provided by an approved vendor). Process  800  can then end at step  812 . 
     When a Headset Tx chip is not successfully authenticated at step  808 , process  800  can disconnect the Headset Rx chip (e.g., Headset Rx  742  of  FIG. 7 ) at step  814  and then reconnect the Power Rx chip (e.g., Power Rx  732  of  FIG. 7 ) at step  816 . For example, a processor can send instructions through a control line (e.g., Control Line  762  of  FIG. 7 ) to a Headset Rx Control System (e.g., Headset Control  760  of  FIG. 7 ) for directing the Headset Rx Control System to disconnect the Headset Rx. Similarly, to reconnect the Power Rx chip, the processor can send instructions through a control line (e.g., Control Line  752  of  FIG. 7 ) to a Power Rx Control System (e.g., Power Control  750  of  FIG. 7 ) for directing it to reconnect the Power Rx chip. 
     At step  818 , process  800  can attempt to authenticate a Power Tx chip (e.g., Power Tx  530  of  FIG. 5 ). For example, a Power Rx chip of the system (e.g., Power Rx  732  of  FIG. 7 ) can sense if a Power Tx chip is attempting to send an authenticating signal such as, for example, a series of pulses through a PWR signal. The Power Rx chip can then analyze any signals that are received. If a received signal includes a series of appropriate PWR signal pulses (e.g., a PWR signal of the appropriate frequency, amplitude, portraying the appropriate current spikes, or any combination of the above) the Power Rx chip can authenticate the Power Tx chip. If the received signal does not include a series of appropriate sine waves, a Power Tx chip may not be authenticated. 
     When a Power Tx chip is authenticated, process  800  can keep its current settings at step  810 . Similar to the authentication of a Headset Tx chip at step  808 , successfully authenticating a Power Tx chip can indicate that a power-providing cable has been coupled to the system. Accordingly, by keeping the current settings and leaving the Headset Rx chip disconnected from the system, the Headset Rx chip can be protected from accidental harm caused by power supplied through the power-providing cable. In some embodiments, the successful authentication can also indicate that an appropriate power-providing cable (e.g., a cable providing an appropriate amount of power or a properly regulated power supply, or a cable that may be provided by an approved vendor) has been coupled to the system. Process  800  can then end at step  812 . 
     When a Power Tx chip is not successfully authenticated at step  818 , the Headset Rx chip (e.g., Headset Rx  742  of  FIG. 7 ) can be reconnected at step  820 . For example, a Headset Rx Control System (e.g., Headset Control  760  of  FIG. 7 ) can be instructed by a processor to reconnect the Headset Rx chip. In some embodiments, failing to authenticate either a Headset Tx chip or a Power Tx can indicate, for example, that an error has occurred in the system. For example, a cable may have been coupled to the system that has a faulty Headset Tx chip or a faulty Power Tx chip. As another example, an unidentifiable or unknown cable-type may have been coupled to the system. As another example, one end of a cable may be coupled to the system, but the other end of the cable may not be attached to anything. Accordingly, since the power-providing cable is not attached to a power source, the power-providing cable may be unable to provide an appropriate series of PWR signal pulses and the authentication may fail. Accordingly, when both a Headset Tx chip and a Power Tx chip fail to authenticate, process  800  can continue to loop through steps  806 ,  808 ,  814 ,  816 ,  818 , and  820  and alternate between attempting to authenticate a Headset Tx chip and a Power Tx chip. Once a Headset Tx chip or Power Tx chip does successfully authenticate, the system can keep its current settings at step  810  and then end at step  812 . 
     The processes discussed here are intended to be illustrative and not limiting. Persons skilled in the art can appreciate that steps of the processes discussed herein can be omitted, modified, combined, or rearranged, and any additional steps can be performed without departing from the scope of the invention. For example, in some embodiments, the order of steps, such as steps  814  and  816 , can be switched, thus resulting in the reconnecting of the Power Rx chip before the disconnecting of the Headset Rx chip. As another example, in some embodiments, steps such as steps  814  and  820  can be omitted. For example, if the system contains a Headset Rx chip that has internal protection to prevent the chip from being harmed by a PWR signal, then it may not be necessary to disconnect and reconnect the Headset Rx chip at step  814  and  820 . 
     As another example, in some embodiments, instead of attempting to authenticate a Headset Rx chip (e.g., steps  806  and  808 ) before attempting to authenticate a Power Rx chip (e.g., steps  814 ,  816 , and  818 ), these steps can be reversed or subject to other conditions. For example, when an electronic device is turned on, there may be a higher likelihood that a user will desire to listen to music instead of trying to recharge the electronic device. Accordingly, since it may be more likely that a headset is coupled to the electronic device, the system can be configured to first check whether a Headset Rx chip can be authenticated when the electronic device is turned on. On the other hand, if the electronic device is turned off, there may be a higher likelihood that a user will desire to recharge the electronic device rather than listen to music. Accordingly, the system can be configured to first check whether a Power Rx chip will authenticate when the system is turned off. Alternatively, since a user typically cannot use an electronic device to listen to music when that device is turned off, in this scenario the device may be configured to only check whether a Power Rx chip will authenticate and to not attempt to authenticate a Headset Rx chip. 
       FIG. 9  shows process  900  that can identify what cable-type has been coupled to a system by determining whether a PWR signal is present. Process  900  may, for example, be used in addition to process  800  or in place of process  800 . Process  900  can begin at step  902 . At step  904 , process  900  can determine whether a cable is coupled to the system. For example, similar to process  800  of  FIG. 8 , a processor can analyze contacts of a port (e.g., contact  758  or contact  760  of  FIG. 7 ) to determine whether a cable is coupled to that port. If a cable is not coupled to the system, process  900  can continue to repeat steps  902  and  904  until a cable is coupled to the system. 
     When a cable is coupled to the system, process  900  can determine whether a PWR signal is being received at step  906 . For example, the contacts of the port to which the cable is coupled can be analyzed to determine whether a PWR signal is present (e.g., contact  764  of  FIG. 7  can be analyzed). 
     If a PWR signal is not present at step  906 , this can indicate that a headset cable (or other suitable non-power providing cable) may be coupled to the system. Accordingly, the Power Rx chip (e.g., Power Rx  732  of  FIG. 7 ) can be disconnected at step  908 . Disconnecting the Power Rx chip can then prevent undesirable leakage current or input capacitance from affecting or harming the performance of the Headset Rx chip and headset cable. Process  900  can then end at step  912 . 
     If, however, a PWR signal is present at step  906 , this can indicate that a power-providing cable may be coupled to the system. Accordingly, the Power Rx chip can be connected at step  910 . Process  900  can then end at step  912 . 
     As mentioned above, in some embodiments a Headset Rx chip may be connected or disconnected in addition to the Power Rx chip. For example, if the Headset Rx chip does not have internal protection against a PWR signal, the PWR signal may cause electrical shorts or otherwise damage the Headset Rx chip. Accordingly, in some embodiments, process  900  may additionally disconnect the Headset Rx chip at optional step  914  when a PWR signal is present. Similarly, when a headset cable is coupled to the system and a PWR signal is not present, the Headset Rx chip can be reconnected at optional step  916 . 
     The processes discussed here are intended to be illustrative and not limiting. Persons skilled in the art can appreciate that steps of the processes discussed herein can be omitted, modified, combined, rearranged, or combinations of these steps, and any additional steps can be performed without departing from the scope of the invention. 
     It will be apparent to those of ordinary skill in the art that methods involved in the present invention may be embodied in a computer program product that includes a machine readable and/or usable medium. For example, such a computer usable medium may consist of a read only memory device, such as a CD ROM disk or conventional ROM devices, or a random access memory, such as a hard drive device or a computer diskette, or flash memory device having a computer readable program code stored thereon. 
     The above described embodiments of the invention are presented for purposes of illustration and not of limitation, and the invention is limited only by the claims which follow.

Metadata:
Filing Date: 20130312
Publication Date: 20140211
Grant Date: 20140211
Priority Date: 20090309
Inventors: BHARGAVA RISHABH
FARRAR DOUG M.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04M1/72409", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/6058", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/72409", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/72409", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/6058", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02J4/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/6058", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 42677593