Apple Inc.

Barry Twycross

David Tupman

Fernando A Urbina

Ken Herman

John Benjamin Filson

Donald Joseph Novotney

Paul Holden

John Wesley Archibald

Daniel R Fletcher

Arulchandran Paramasivam

James Hollowell

J Rhoads Hollowell, Ii

Arul Paramasivam

David John Tupman

Methods and apparatus for reliable detection and enumeration of devices. In one embodiment, the controller comprises serialized bus protocol (e.g., a Universal Serial Bus (USB)) controller capable of supporting different bus architectures (e.g., USB 2.0 and USB 3.0) of the USB protocol (e.g., eXtensible Host Controller Interface (xHCI) controller). In one variant, when a USB-compliant device is detected over multiple bus architectures of a controller, the controller waits an additional period to allow the device to properly identify which bus architecture to use. After the time period has elapsed, if the device has been determined to be connected over the USB 3.0 bus architecture, the controller waits an additional period of time before enumerating the device. If the device is still present on the USB 3.0 bus architecture, the device continues to enumerate as a USB 3.0 advice to be made available to a host system.

Methods and apparatus for reliable detection and enumeration of devices

Methods and apparatus for enhancing efficiency (e.g., reducing power consumption and bus activity) in a data bus. In an exemplary embodiment, methods and apparatus for intelligently trimming (and adding or re-adding) queue heads resident in a host device associated with various client device processes are disclosed. By selectively trimming inactive or dormant queue heads, the host expends less resources and time polling the queue heads during routine operations. Similarly, queue heads which are newly active, or acquired are intelligently added to ensure proper bus operation. Inactive queue heads are brought back into the polling process only when requested, thereby keeping the list of queue heads to be polled or examined as short as possible at all times.

Methods and apparatus for decreasing power consumption and bus activity

Improved techniques to recognize a power source on a peripheral bus and/or determine power available from the power source via the peripheral bus are disclosed. Typically, the peripheral bus is supported by a cable connected between a host device and an electronic device. In this case, the host device is a power source (e.g., power adapter or battery pack) and the cable is used to provide power from the power source to the electronic device. Hence, by understanding the power available from the power source, the electronic device can manage its power utilization so as to operate in a stable and reliable manner. The electronic device is, for example, a portable computing device. Examples of portable computing devices include a Portable Digital Assistant (PDA) and a portable media player.

Method and system for discovering a power source on a peripheral bus

A method and system for allowing a media player to transfer digital audio to an accessory is disclosed. The method and system comprises sending a play command to the media player; returning information about the media player; and providing digital audio to the accessory based upon the information about the media player. In a system and method in accordance with the present invention a plurality of commands allow a media player to transfer digital audio to an accessory. These commands are used by the media player to gather a list of supported sample rates from the accessory and to inform the accessory of the media player's information.

Method and system for allowing a media player to transfer digital audio to an accessory

Digital audio can be transferred between a portable media player and an accessory. In one embodiment, an interface protocol is used to determine the sample rate capabilities of an accessory, allowing digital audio data for a track to be transmitted to the accessory at a sample rate supported by the accessory. When the sample rate of an audio track is not supported by the accessory, the media player can convert the sample rate of the track to a rate supported by the accessory and transmit the track after conversion. The media player also can use the interface protocol to inform the accessory if the sampling rate should be changed, e.g., due to tracks having different sample rates. The accessory then can send a request to the media player to change the sample rate. The media player then can transmit the digital audio data using the new sample rate.

Growing community of inventors

Mountain View, CA, United States of America

Barry Twycross