SMSC USB2502 - Manual (Page 17)

2-Port USB 2.0 Hub Controller
Datasheet
SMSC USB2502 17 Revision 2.3 (08-27-07)
DATASHEET
5.1.1.5 High-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.
5.1.1.6 EOP 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.
5.1.1.7 Current 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)
5.1.1.8 Compound 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.
5.1.1.9 Non-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.
5.1.1.10 Self-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.
5.1.1.11 Bus-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.
5.1.1.12 Dynamic 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.}