Datasheet

USB 2.0 Hi-Speed Hub Controller
Datasheet
Revision 2.2 (02-17-12) 48 SMSC USB251xB/xBi
DATASHEET
5.5.2 USB Bus Reset
In response to the upstream port signaling a reset to the hub, the hub does the following:
1. Sets default internal USB address to 0
2. Sets configuration to: unconfigured
3. Negates PRTPWR[x:1] to all downstream ports unless battery charging (BC_EN[x:1]) is enabled
4. Clears all TT buffers
5. Moves device from suspended to active (if suspended)
6. Complies with Section 11.10 of the
USB 2.0 Specification [1] for behavior after completion of the
reset sequence. The host then configures the hub and the hub’s downstream port devices in
accordance with the
USB Specification.
Note: The hub does not propagate the upstream USB reset to downstream devices.