USB 2.0 Hi-Speed 2-Port Hub Controller
Datasheet
5.1.6
Battery Charger Detection Stage (CHGDET)
After configuration, if enabled, the device enters the Battery Charger Detection Stage. If the battery
charger detection feature was disabled during the CONFIG stage, the device will immediately
transition to the Hub Connect (Hub.Connect) stage. If the battery charger detection feature remains
enabled, the battery charger detection sequence is started automatically.
If the charger detection remains enabled, the device will transition to the Hub.Connect stage if using
the hardware detection mechanism.
5.1.7
5.1.8
Hub Connect Stage (Hub.Connect)
Once the CHGDET stage is completed, the device enters the Hub.Connect stage.
Normal Mode
Lastly the SOC enters the Normal Mode of operation. In this stage, full USB operation is supported
under control of the USB Host on the upstream port. The device will remain in the normal mode until
the operating mode is changed by the system. The only device registers accessible to the SOC are
the run time registers described in Section 7.2.1, "SMBus Run Time Accessible Registers," on page 31.
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.
To save power, communication over the SMBus is not supported while in USB Suspend. 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.
Revision 1.0 (06-17-13)
24
SMSC USB2532
DATASHEET
SMSC [ SMSC CORPORATION ]
