USB 2.0 Hi-Speed Hub Controller
Datasheet
Revision 1.0 (3-11-09) 40 SMSC USB251x
DATASHEET
8.2.1.9 Register 08h: Configuration Data Byte 3
8.2.1.10 Register 09h: Non-Removable Device
BIT
NUMBER BIT NAME DESCRIPTION
7:4 Reserved Reserved
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 LED_MODE LED Mode Selection: The LED_A[x:1]_N and LED_B[x:1]_N pins support
several different modes of operation (depending upon OEM implementation
of the LED circuit).
‘00' = USB Mode
‘01’ = Speed Indication Mode
‘10’ = Same as ‘00’, USB Mode
‘11’ = Same as ‘00’, USB Mode
Warning: Do not enable an LED mode that requires LED pins that are not
available in the specific package being used in the implementation.
Note: The hub will only report that it supports LED's to the host when
USB mode is selected. All other modes will be reported as No LED
Support.
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(s) include non-removable
devices.
‘0’ = port is removable
‘1’ = port is non-removable
Informs the host if one of the active ports has a permanent device that is
undetachable from the hub. (Note: The device must provide its own
descriptor data.)
When using the internal default option, the NON_REM[1:0] pins will
designate the appropriate ports as being non- removable.
Bit 7= Controls Port 7
Bit 6= Controls Port 6
Bit 5= Controls Port 5
Bit 4= Controls Port 4
Bit 3= Controls Port 3
Bit 2= Controls Port 2
Bit 1= Controls Port 1
Bit 0= Reserved