Artesyn SCP-P4040-4G-ENP2 Installation and Use (August 2014) - Manual (Page 53)

Functional Description
SCP-P4040-4G-ENP2 Installation and Use (6806800P60B) 53
The SMSC Hub must be configured in order to correctly function when attached to a USB host
controller. There are three principal ways to configure the hub: SMBus, EEPROM, or by internal
default setting. In all cases, the configuration method will be determined by the CFG_SEL2,
CFG_SEL1 and CFG_SEL0 pins immediately after RESET_N negation.
In SMBus case, the CFG_SEL1 and CFG_SEL0 pins must be 01, so that Hub can be configured as
an SMBus slave for external download of user-defined descriptors.
U-boot should initialize USB hub during boot-up and provide u-boot commands for
reading/writing the hub's registers.