Table 3.7 boost_up register (boostup) format, Table 3.8 boost_3:2 register (boost32) format, For d – SMSC LAN9512 User Manual

Page 30: Port re-mapping enable (prtmap_en), Config data byte 3 register (cfg3), Format, The h, Datasheet

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USB Hub with Integrated 10/100 Ethernet Controller

Datasheet

Revision 1.0 (04-20-09)

30

SMSC LAN9512

DATASHEET

Table 3.6 Config Data Byte 3 Register (CFG3) Format

BITS

DESCRIPTION

DEFAULT

7:4

RESERVED

0h

3

Port Re-Mapping Enable (PRTMAP_EN)

Selects the method used by the Hub to assign port numbers and disable

ports.

0 = Standard Mode. The following EEPROM addresses are used to define

which ports are enabled. The ports mapped as Port’n’ on the Hub are

reported as Port’n’ to the host, unless one of the ports is disabled, then the

higher numbered ports are remapped in order to report contiguous port

numbers to the host.

EEPROM Address 2Ah: Port Disable for Self-Powered operation

EEPROM Address 2Bh: Port Disable for Bus-Powered operation

1 = Port Re-Map mode. The mode enables remapping via the following

EEPROM addresses:

EEPROM Address 36h: Port Remap 12

EEPROM Address 37h: Port Remap 3

0b

2:0

RESERVED

000b

Table 3.7 Boost_Up Register (BOOSTUP) Format

BITS

DESCRIPTION

DEFAULT

7:2

RESERVED

000000b

1:0

Upstream USB Electrical Signaling Drive Strength Boost Bit for

Upstream Port A (BOOST_IOUT_A)

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

Table 3.8 Boost_3:2 Register (BOOST32) Format

BITS

DESCRIPTION

DEFAULT

7:6

RESERVED

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

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