Datasheet

USB 2.0 Hi-Speed Hub Controller
Datasheet
Revision 2.2 (02-17-12) 32 SMSC USB251xB/xBi
DATASHEET
5.1.9 Register 08h: Configuration Data Byte 3
5.1.10 Register 09h: Non-Removable Device
BIT
NUMBER BIT NAME DESCRIPTION
7:4 rsvd
3 PRTMAP_EN Port Mapping Enable: selects the method used by the hub to assign port
numbers and disable ports.
0 : standard mode
1 : port mapping mode
2:1 rsvd
0 STRING_EN Enables String Descriptor Support
0 : string support disabled
1 : string support enabled
BIT
NUMBER BIT NAME DESCRIPTION
7:0 NR_DEVICE Non-Removable Device: indicates which port has a non-removable device.
0 : port is removable
1 : port is non-removable
Bit 7 : rsvd
Bit 6 : rsvd
Bit 5 : rsvd
Bit 4 : controls port 4
Bit 3 : controls port 3
Bit 2 : controls port 2
Bit 1 : controls port 1
Bit 0 : rsvd
Note: The device must provide its own descriptor data.
When using the default configuration, the NON_REM[1:0] pins will designate
the appropriate ports as being non-removable.