Datasheet

USB 2.0 Hub and 10/100 Ethernet Controller
Datasheet
Revision 1.2 (02-29-12) 32 SMSC LAN9512/LAN9512i
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