Integrated USB 2.0 Compatible 4-Port Hub

Datasheet

5.1.1.5Port Indicators

Controls the use of LED indicator for Port status information. See Section 11.5.3 of the USB 2.0 Specification for additional details.

This field is set by the OEM using either the SMBus or EEPROM interface options. When using the internal default option, the LED_EN pin enables/disables LED Indicator support.

5.1.1.6High-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.

5.1.1.7Multiple-TT Support

Selects between a mode where only one transaction translator is available for all ports (Single-TT), or each port gets a dedicated transaction translator (Multi-TT) {Note: The host may force Single-TT mode only}.

This field is set by the OEM using either the SMBus or EEPROM interface options. When using the internal default option, the MTT_EN pin enables/disables MTT support.

5.1.1.8EOP 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.

5.1.1.9Current Sensing

Selects current sensing on a port-by-port basis, all ports ganged, or none(only for bus-powered hubs)The ability to support current sensing on a port or ganged basis is hardware implementation dependent.

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)

5.1.1.10Downstream Port Power Enabling

Enables all ports simultaneously (ganged), or port power is individually switched on and off on a port- by-port basis. The ability to support power enabling on a port or ganged basis is hardware implementation dependent.

This field is set by the OEM using either the SMBus or EEPROM interface options. When using the internal default option, the GANG_EN pin will configure the hub for ganged or individual port-by-port port power switching.

5.1.1.11Compound 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.

SMSC USB2504/USB2504A

17

Revision 2.3 (08-27-07)

 

DATASHEET