20H04 Datasheet, PDF (30/38 Pages) SMSC Corporation – 4-PORT USB2.0 HUB CONTROLLER

4-Port USB2.0 Hub Controller
Datasheet
8.4.2 USB Reset
When the upstream host signals a reset, the USB20H04 does the following:
Note: The USB20H04 does not propagate the upstream USB Reset to downstream devices!
1. Sets default address to 0
2. Sets configuration to: un-configured
3. Negates VBUSx_N (where x stands for the port number) to all downstream ports.
4. Clears all TT buffers.
5. Moves device from suspended to active (if suspended).
6. Complies with Section 11.10 of the USB2.0 specification 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.
Revision 1.63 (10-14-04)
Page 30
DATASHEET
SMSC USB20H04