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US 8,713,209 B2Granted
System, apparatus, and method for fast startup of USB devices
AssigneeQUALCOMM Incorporated
InventorSteven F. Harris
Life of this patent
Estimating the term…
Abstract
Exemplary embodiments are directed to fast enumeration of a device in a USB system including a USB device and a USB host. The USB device includes two device descriptors, a memory for holding firmware for operation of the USB device, and a controller for executing the firmware. A first device descriptor is for enumerating the USB device in a firmware-loading mode and a second device descriptor is for enumerating the USB device in an operational mode. The USB host controls a first enumeration of the USB device using the first device descriptor. After the first enumeration, the USB host receives a re-enumerate indicator from the USB device and controls a second enumeration of the USB device using the second device descriptor.
Claims32
A USB device, comprising:
- a memory for holding firmware for operation of the USB device;
- a controller for executing the firmware;
- a first device descriptor for enumerating the USB device in a firmware-loading mode for generating a first USB stack during a first stage of a dual-enumeration process;
- and
- a second device descriptor for enumerating the USB device in an operational mode upon completion of the firmware-loading mode of the first stage of the dual-enumeration process and in response to a re-enumerate indicator generated by the USB device for generating a second USB stack to replace the first USB stack during a second, different stage of the dual-enumeration process;
- wherein firmware comprises:
- first firmware for controlling the firmware-loading mode;
- and
- second firmware for controlling the operational mode.
6 more elements
A USB host for operable coupling to a USB device and comprising computing instruction for execution by a computer, to:
- perform a first stage of a dual-enumeration process of the USB device using a first device descriptor from the USB device after a first portion of firmware has been downloaded by the USB device to generate a first USB stack;
- receive a re-enumerate indicator from the USB device;
- and
- perform a second, different stage of the dual-enumeration process of the USB device using a second device descriptor from the USB device upon completion of the firmware-loading mode of the first stage of the dual-enumeration process and in response to the re-enumerate indicator after a second, different portion of firmware has been downloaded by the USB device to generate a second USB stack to replace the first USB stack.
1 more element
A system, comprising:
- a USB device, comprising:
- a memory for holding firmware for operation of the USB device;
- a controller for executing the firmware;
- a first device descriptor for enumerating the USB device in a firmware-loading mode for generating a first USB stack during a first stage of a dual-enumeration process;
- and
- a second device descriptor for enumerating the USB device in an operational mode upon completion of the firmware-loading mode of the first stage of the dual-enumeration process and for generating a second USB stack to replace the first USB stack during a second, different stage of the dual-enumeration process;
- and
- a USB host operably coupled to the USB device and for controlling the USB device by:
- controlling a first enumeration of the USB device using the first device descriptor;
- and
- after the first enumeration:
- receiving a re-enumerate indicator from the USB device;
- and
- controlling a second enumeration of the USB device using the second device descriptor.
11 more elements
A method, comprising:
- detecting a USB device on a USB topology;
- enumerating the USB device with a first firmware and a first device descriptor of the USB device in a firmware-loading mode for generating a first USB stack during a first stage of a dual-enumeration process;
- enabling the USB device for access by first client software in the firmware-loading mode;
- downloading a second firmware to a memory of the USB device;
- enumerating the USB device with a second device descriptor of the USB device in an operational mode upon completion of the firmware-loading mode of the first stage of the dual-enumeration process and in response to a re-enumerate indicator generated by the USB device for generating a second USB stack to replace the first USB stack during a second, different stage of the dual-enumeration process;
- and
- enabling the USB device for access by second client software in the operational mode using the second firmware.
4 more elements
A system, comprising:
- means for detecting a USB device on a USB topology;
- means for enumerating the USB device with a first firmware and a first device descriptor of the USB device in a firmware-loading mode for generating a first USB stack during a first stage of a dual-enumeration process;
- means for enabling the USB device for access by first client software in the firmware-loading mode;
- means for downloading a second firmware to a memory of the USB device;
- means for enumerating the USB device with a second device descriptor of the USB device in an operational mode upon completion of the firmware-loading mode of the first stage of the dual-enumeration process and in response to a re-enumerate indicator generated by the USB device for generating a second USB stack to replace the first USB stack during a second, different stage of the dual-enumeration process;
- and
- means for enabling the USB device for access by second client software in the operational mode using the second firmware.
4 more elements
Dependencies are inferred from the claim text.