2-Port USB 2.0 Hub Controller

Datasheet

5.1.1.5High-Speed Disable

Allows an OEM to force the Hub to configure as a Full-Speed device only (i.e. High-Speed not available).

This field is set by the OEM using either the SMBus or EEPROM interface options.

5.1.1.6EOP Disable

During FS operation only, this permits the Hub to send EOP if no downstream traffic is detected at EOF1. See Section 11.3.1 of the USB 2.0 Specification for additional details.

This field is set by the OEM using either the SMBus or EEPROM interface options.

5.1.1.7Current Sensing

Selects current sensing as all ports ganged, or none.

This field can be set by the OEM using either the SMBus or EEPROM interface options.When using the internal default option, the SELF_PWR pin determines if current sensing will be ganged, or none (ganged if self-powered, none if bus-powered)

5.1.1.8Compound Device

Allows the OEM to indicate that the Hub is part of a compound (see the USB Specification for definition) device. The applicable port(s) must also be defined as having a “Non-Removable Device”.

This field is set by the OEM using either the SMBus or EEPROM interface options.

Note: When configured via strapping options, declaring a port as non-removable automatically causes the hub controller to report that it is part of a compound device.

5.1.1.9Non-Removable Device

Informs the Host if one of the active ports has a permanent device that is undetachable from the Hub. (Note: The device must provide its own descriptor data.)

This field is set by the OEM using either the SMBus or EEPROM interface options. When using the internal default option, the NON_REM[1:0] pins will designate the appropriate ports as being non- removable.

5.1.1.10Self-Powered Port DISABLE

During Self-Powered operation, this selects the ports which will be permanently disabled, and are not available to be enabled or enumerated by a Host Controller. The disabled ports must be in decreasing order starting with port 2.

This field is set by the OEM using either the SMBus or EEPROM interface options.

5.1.1.11Bus-Powered Port DISABLE

During Bus-Powered operation, this selects the ports which will be permanently disabled, and are not available to be enabled or enumerated by a Host Controller. The disabled ports must be in decreasing order starting with port 2.

This field is set by the OEM using either the SMBus or EEPROM interface options.

5.1.1.12Dynamic Power

Controls the ability of the 2-Port Hub to automatically change from Self-Powered operation to Bus- Powered operation if the local power source is removed or is unavailable (and from Bus-Powered to Self-Powered if the local power source is restored). {Note: If the local power source is available, the 2-port Hub will always switch to Self-Powered operation.}

SMSC USB2502

17

Revision 2.3 (08-27-07)

 

DATASHEET