USB2513 datasheet(36/48 Pages) SMSC

36 / 48 page

USB 2.0 High-Speed 3-Port Hub Controller

Datasheet

Revision 1.98 (11-19-07)

SMSC USB2513

DATASHEET

4.4.7

Bus Reset Sequence

The SMBus Slave Interface resets and returns to the idle state upon a START field followed

immediately by a STOP field.

4.4.8

SMBus Alert Response Address

The SMBALERT# signal is not supported by the Hub.

4.4.8.1

Undefined Registers

The registers shown in Table 4.2 are the defined registers in the Hub. Reads to undefined registers

return 00h. Writes to undefined registers have no effect and do not return an error.

4.4.8.2

Reserved Registers

Unless otherwise instructed, only a ‘0’ may be written to all reserved registers or bits.

4.5

Default Configuration Option:

The SMSC Hub can be configured via its internal default configuration. (please see Section 4.3.1,

"Internal Register Set (Common to EEPROM and SMBus)" for specific details on how to enable default

configuration.)

Please refer to Table 4.2 for the internal default values that are loaded when this option is selected.

4.6

Default Strapping Options:

The USB2514 can be configured via a combination of internal default values and pin strap options.

Please see Table 3.1 and Table 3.2 for specific details on how to enable the default/pin-strap

configuration option.

The strapping option pins only cover a limited sub-set of the configuration options. The internal default

values will be used for the bits & registers that are not controlled by a strapping option pin. Please

refer to Table 4.2 for the internal default values that are loaded when this option is selected.

The Green LED pins are sampled after RESET_N negation, and the logic values are used to configure

the hub if the internal default configuration mode is selected. The implementation shown below (see

Figure 4.3) shows a recommended passive scheme. When a pin is configured with a “Strap High”

configuration, the LED functions with active low signalling, and the PAD will “sink” the current from the

external supply. When a pin is configured with a “Strap Low” configuration, the LED functions with

active high signalling, and the PAD will “source” the current to the external LED.

USB2513 Datenblatt(PDF) 36 Page - SMSC Corporation