USB Hub with Integrated 10/100 Ethernet Controller

Datasheet

Table 3.4 Config Data Byte 1 Register (CFG1) Format

BITS

 

DESCRIPTION

DEFAULT

 

 

 

7

Self or Bus Power (SELF_BUS_PWR)

1b

 

Selects between Self or Bus-Powered operation.

 

 

0 = Bus-Powered

 

 

1 = Self-Powered

 

 

The Hub is either Self-Powered (draws less than 2mA of upstream bus

 

 

power) or Bus-Powered (limited to a 100mA maximum of upstream power

 

 

prior to being configured by the host controller).

 

 

When configured as a Bus-Powered device, the SMSC Hub consumes less

 

 

than 100mA of current prior to being configured. After configuration, the Bus-

 

 

Powered SMSC Hub (along with all associated hub circuitry, any embedded

 

 

devices if part of a compound device, and 100mA per externally available

 

 

downstream port) must consume no more than 500mA of upstream VBUS

 

 

current. The current consumption is system dependent, and the OEM must

 

 

ensure that the USB2.0 specifications are not violated.

 

 

When configured as a Self-Powered device, <1mA of upstream VBUS

 

 

current is consumed and all ports are available, with each port being capable

 

 

of sourcing 500mA of current.

 

 

 

 

6

RESERVED

0b

 

 

 

5

High Speed Disable (HS_DISABLE)

0b

 

Disables the capability to attach as either a High/Full-Speed device, and

 

 

forces attachment as Full-Speed only (no High-Speed support).

 

 

0 = High-/Full-Speed

 

 

1 = Full-Speed-Only (High-Speed disabled)

 

 

 

 

4

Multiple TT Enable (MTT_ENABLE)

1b

 

Enables one transaction translator per port operation.

 

 

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}.

 

 

0 = Single TT for all ports.

 

 

1 = One TT per port (multiple TT's supported)

 

 

 

 

3

EOP Disable (EOP_DISABLE)

1b

 

Disables EOP generation of EOF1 when in Full-Speed mode. 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.

 

 

Note:

Generation of an EOP at the EOF1 point may prevent a Host

 

 

 

controller (operating in FS mode) from placing the USB bus in

 

 

 

suspend.

 

 

0 = An EOP is generated at the EOF1 point if no traffic is detected.

 

 

1 = EOP generation at EOF1 is disabled (note: this is normal USB

 

 

operation).

 

 

Note:

This is a rarely used feature in the PC environment, existing drivers

 

 

 

may not have been thoroughly debugged with this feature enabled.

 

 

 

It is included because it is a permitted feature in Chapter 11 of the

 

 

 

USB specification.

 

 

 

 

 

SMSC LAN9514

29

Revision 1.0 (04-20-09)

 

DATASHEET