USB3813 datasheet(23/68 Pages) SMSC

23 / 68 page

USB 2.0 Hi-Speed 3-Port Hub Controller Optimized for Portable Applications

Datasheet

SMSC USB3813

Revision 1.0 (06-17-13)

DATASHEET

the operating mode is changed by the system. The only device registers accessible to the SOC are

the run time registers described in Section 7.3.1, "SMBus Run Time Accessible Registers," on page 35.

If RESET_N is asserted low, then Standby Mode is entered. The device may then be placed into any

of the designated Hub stages. Asserting the soft disconnect on the upstream port will cause the Hub

to return to the Hub.Connect stage until the soft disconnect is negated. If the HUB_CONN pin

transitions from asserted to negated, the device will return to the Hub.Connect stage.

To save power, communication over the SMBus is not supported while in USB Suspend. The system

can, however, command the device to wake up by the asserting the IRQ_N pin. The system can

prevent the device from going to sleep by asserting the ClkSusp control bit of the Configure Portable

Hub Register anytime before entering USB Suspend. While the device is kept awake during USB

Suspend, it will provide the SMBus functionality at the expense of not meeting USB requirements for

average suspend current consumption.

USB3813 数据表(PDF) 23 Page - SMSC Corporation