2 Interface USB 3.0 SuperSpeed
2.11 Bus inventory

When you connect or disconnect a terminal device from the USB, the host uses a process called as bus inventory to identify and manage the state of the terminal device. This process consists of several following steps:

  1. The hub, where the terminal device is connected, inform the host about this event through a special channel (terminal device is at this moment after the RESET command in the default state, i.e. it cannot take more than 150 mA from VBUS wire and responds to the default address.)
  2. Then the host determines the exact nature of the event by request to the hub. If the host knows the port to which the terminal device is connected, it can reactivate RESET command for terminal device.
  3. Subsequently, the host assign to terminal device a unique address and it informs the terminal device about synchronous delay and several other parameters.
  4. There will be also realized reading of all configurations of terminal device by host and it will be realized eventual timer settings U1/U2 for downlink port which is occupied by the terminal device.
  5. The host determines values required to set the terminal device on the basis of information about configurations and how to use the terminal device. Terminal device will come on state CONFIGURED and it is now ready for use.

In case of a disconnection of terminal device is sent the notice message to the hub and the host can update the local topology information.