SMSC LAN9514 Manual Do Utilizador

USB Hub with Integrated 10/100 Ethernet Controller

Datasheet

Revision 1.0 (04-20-09)

SMSC LAN9514

DATASHEET

Table 3.9 Boost_4:2 Register (BOOST42) Format

BITS

DESCRIPTION

DEFAULT

7:6

Upstream USB Electrical Signaling Drive Strength Boost Bit for

Downstream Port 4 (BOOST_IOUT_4)

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)

00b

5:4

Upstream USB Electrical Signaling Drive Strength Boost Bit for

Downstream Port 3 (BOOST_IOUT_3)

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)

00b

3:2

Upstream USB Electrical Signaling Drive Strength Boost Bit for

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)

00b

1:0

RESERVED

00b

Table 3.10 Status/Command Register (STCD) Format

BITS

DESCRIPTION

DEFAULT

7:2

RESERVED

000000b

Reset (RESET)

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.

USB Attach and Write Protect (USB_ATTACH)

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.