Abstract: Systems and methods for using distributed Universal Serial Bus (USB) host drivers are disclosed. In one aspect, USB packet processing that was historically done on an application processor is moved to a distributed USB driver running in parallel on a low-power processor such as a digital signal processor (DSP). While a DSP is particularly contemplated, other processors may also be used. Further, a communication path is provided from the low-power processor to USB hardware that bypasses the application processor. Bypassing the application processor in this fashion allows the application processor to remain in a sleep mode for longer periods of time instead of processing digital data received from the low-power processor or the USB hardware. Further, by bypassing the application processor, latency is reduced, which improves the listener experience.

Abstract: Systems and method for inferring polling rates for Universal Serial Bus (USB) endpoints include a driver in an audio device that measures a feedback polling interval from a host device for a plurality of periods. Based on observed periods, the audio device infers a polling period by the host device and adjusts when a feedback signal is sent to conform to the inferred polling period. By adjusting the audio device based on behavior of the operating system, the audio device may work with multiple operating systems, providing greater flexibility for an end user and also reducing the likelihood of artifacts degrading the user experience.

Abstract: Apparatuses, methods, and systems for enabling higher current charging of Universal Serial Bus (USB) Specification Revision 2.0 (USB 2.0) portable electronic devices from USB 3.x hosts are disclosed. In one aspect, a USB 2.0 controller is provided in a USB 2.0 portable device. A USB 3.x controller is provided in a USB 3.x host. The USB 2.0 controller is configured to draw a higher charging current than specified in USB 2.0 for the USB 2.0 portable device over a USB 2.0 cable. In order to draw the higher charging current without violating USB 2.0, the USB 2.0 controller is configured to use one or more reserved elements in an existing USB 2.0 descriptor(s) or bitmap(s) to indicate a higher charging current request from the USB 2.0 controller.

Abstract: Systems and methods for using distributed Universal Serial Bus (USB) host drivers are disclosed. In one aspect, USB packet processing that was historically done on an application processor is moved to a distributed USB driver running in parallel on a low-power processor such as a digital signal processor (DSP). While a DSP is particularly contemplated, other processors may also be used. Further, a communication path is provided from the low-power processor to USB hardware that bypasses the application processor. Bypassing the application processor in this fashion allows the application processor to remain in a sleep mode for longer periods of time instead of processing digital data received from the low-power processor or the USB hardware. Further, by bypassing the application processor, latency is reduced, which improves the listener experience.

Abstract: A method of triggering a desired operating mode in a universal serial bus (USB)-compatible client device is provided. A USB-compatible client device detects that it has been coupled to a USB-compatible host device via a USB bus. The USB-compatible client device attempts to pull a data line of the USB bus high. The USB-compatible client device then ascertains that the data line remains pulled low, thereby indicating that the USB-compatible client device should enter a first mode of operation. The USB-compatible client device operates according to the first mode of operation.

Abstract: Electronic devices are adapted to facilitate detection of a type of USB charger to which an electronic device is connected. According to one example, an electronic device can apply a current source to a data line of a USB plug coupled to a USB port. A determination can be made whether the data line has gone to a LOW state or remained at a HIGH state after a predetermined period of time. If the data line has gone to a LOW state, the USB port may be identified as a downstream port, such as a standard downstream port (SDP) or a charging downstream port (CDP). If the data line has remained at the HIGH state, the USB port may be identified as a dedicated charging port (DCP), no matter if it is compliant or non-compliant with the BC 1.2 spec. Other aspects, embodiments, and features are also included.

Abstract: Apparatuses and methods to distinguish proprietary, non-floating and floating chargers for regulating charging current are disclosed. In one aspect, a charger detection circuit is provided in a portable electronic device. The charger detection circuit is configured to detect whether a connected Universal Serial Bus (USB) charger is compliant with a USB battery charging specification. If the connected USB charger is non-compliant with the USB battery charging specification, the charger detection circuit is configured to further detect if the non-complaint USB charger is a non-compliant floating USB charger or a non-compliant proprietary USB charger. If the connected USB charger is determined to be a non-compliant proprietary USB charger, the portable electronic device can be configured to draw up to a maximum charging current according to the USB battery charging specification.

Abstract: A method of triggering a desired operating mode in a universal serial bus (USB)-compatible client device is provided. A USB-compatible client device detects that it has been coupled to a USB-compatible host device via a USB bus. The USB-compatible client device attempts to pull a data line of the USB bus high. The USB-compatible client device then ascertains that the data line remains pulled low, thereby indicating that the USB-compatible client device should enter a first mode of operation. The USB-compatible client device operates according to the first mode of operation.

Abstract: Apparatuses and methods to distinguish proprietary, non-floating and floating chargers for regulating charging current are disclosed. In one aspect, a charger detection circuit is provided in a portable electronic device. The charger detection circuit is configured to detect whether a connected Universal Serial Bus (USB) charger is compliant with a USB battery charging specification. If the connected USB charger is non-compliant with the USB battery charging specification, the charger detection circuit is configured to further detect if the non-complaint USB charger is a non-compliant floating USB charger or a non-compliant proprietary USB charger. If the connected USB charger is determined to be a non-compliant proprietary USB charger, the portable electronic device can be configured to draw up to a maximum charging current according to the USB battery charging specification.

Abstract: Apparatuses, methods, and systems for enabling higher current charging of Universal Serial Bus (USB) Specification Revision 2.0 (USB 2.0) portable electronic devices from USB 3.x hosts are disclosed. In one aspect, a USB 2.0 controller is provided in a USB 2.0 portable device. A USB 3.x controller is provided in a USB 3.x host. The USB 2.0 controller is configured to draw a higher charging current than specified in USB 2.0 for the USB 2.0 portable device over a USB 2.0 cable. In order to draw the higher charging current without violating USB 2.0, the USB 2.0 controller is configured to use one or more reserved elements in an existing USB 2.0 descriptor(s) or bitmap(s) to indicate a higher charging current request from the USB 2.0 controller.

Abstract: Apparatuses and methods to distinguish proprietary, non-floating and floating chargers for regulating charging current are disclosed. In one aspect, a charger detection circuit is provided in a portable electronic device. The charger detection circuit is configured to detect whether a connected Universal Serial Bus (USB) charger is compliant with a USB battery charging specification. If the connected USB charger is non-compliant with the USB battery charging specification, the charger detection circuit is configured to further detect if the non-complaint USB charger is a non-compliant floating USB charger or a non-compliant proprietary USB charger. If the connected USB charger is determined to be a non-compliant proprietary USB charger, the portable electronic device can be configured to draw up to a maximum charging current according to the USB battery charging specification.

Abstract: Electronic devices are adapted to facilitate detection of a type of USB charger to which an electronic device is connected. According to one example, an electronic device can apply a current source to a data line of a USB plug coupled to a USB port. A determination can be made whether the data line has gone to a LOW state or remained at a HIGH state after a predetermined period of time. If the data line has gone to a LOW state, the USB port may be identified as a downstream port, such as a standard downstream port (SDP) or a charging downstream port (CDP). If the data line has remained at the HIGH state, the USB port may be identified as a dedicated charging port (DCP), no matter if it is compliant or non-compliant with the BC 1.2 spec. Other aspects, embodiments, and features are also included.

Abstract: A method of triggering a desired operating mode in a universal serial bus (USB)-compatible client device is provided. A USB-compatible client device detects that it has been coupled to a USB-compatible host device via a USB bus. The USB-compatible client device attempts to pull a data line of the USB bus high. The USB-compatible client device then ascertains that the data line remains pulled low, thereby indicating that the USB-compatible client device should enter a first mode of operation. The USB-compatible client device operates according to the first mode of operation.

Abstract: A method of triggering a desired operating mode in a universal serial bus (USB)-compatible client device is provided. A USB-compatible client device detects that it has been coupled to a USB-compatible host device via a USB bus. The USB-compatible client device attempts to pull a data line of the USB bus high. The USB-compatible client device then ascertains that the data line remains pulled low, thereby indicating that the USB-compatible client device should enter a first mode of operation. The USB-compatible client device operates according to the first mode of operation.