USB Hub with Integrated 10/100 Ethernet Controller

Datasheet

Table 3.8 Boost_3:2 Register (BOOST32) Format (continued)

BITS

 

DESCRIPTION

DEFAULT

 

 

 

3:2

Upstream USB Electrical Signaling Drive Strength Boost Bit for

00b

 

Downstream Port 2 (BOOST_IOUT_2)

 

 

00

= Normal electrical drive strength

 

 

01

= Elevated electrical drive strength (+4% boost)

 

 

10

= Elevated electrical drive strength (+8% boost)

 

 

11 = Elevated electrical drive strength (+12% boost)

 

 

 

 

1:0

RESERVED

00b

 

 

 

 

Table 3.9 Status/Command Register (STCD) Format

BITS

 

 

DESCRIPTION

DEFAULT

 

 

 

7:2

RESERVED

000000b

 

 

 

1

Reset (RESET)

0b

 

Resets the internal memory back to nRESET assertion default settings.

 

 

0

= Normal Run/Idle State

 

 

1

= Force a reset of the registers to their default state

 

 

Note:

During this reset, this bit is automatically cleared to its default value

 

 

 

 

of 0.

 

 

 

 

0

USB Attach and Write Protect (USB_ATTACH)

1b

 

0

= Device is in configuration state

 

 

1

= Hub will signal a USB attach event to an upstream device, and the

 

 

internal memory (address range 00h - FEh) is “write-protected” to prevent

 

 

unintentional data corruption.

 

 

Note:

This bit is write once and is only cleared by assertion of the external

 

 

 

 

nRESET or POR.

 

 

 

 

 

 

SMSC LAN9512

31

Revision 1.0 (04-20-09)

 

DATASHEET