USB 2.0 Hi-Speed Hub Controller

Datasheet

 

 

8.2.1.25

Register 92h-CFh: Serial String

 

 

 

BIT

 

 

NUMBER

BIT NAME

DESCRIPTION

 

 

 

7:0

SER_STR

Serial String, UNICODE UTF-16LE per USB 2.0 specification

 

 

When supported, the maximum string length is 31 characters (62 bytes).

 

 

Note: The string consists of individual 16-bit UNICODE UTF-16LE

 

 

characters. The Characters will be stored starting with the LSB at

 

 

the least significant address and the MSB at the next 8-bit location

 

 

(subsequent characters must be stored in sequential contiguous

 

 

address in the same LSB, MSB manner). Some EEPROM

 

 

programmers may transpose the MSB and LSB, thus reversing the

 

 

Byte order. Please pay careful attention to the Byte ordering or

 

 

your selected programming tools.

 

 

 

8.2.1.26Register D0h: Battery Charging Enable

BIT

 

 

NUMBER

BIT NAME

DESCRIPTION

 

 

 

7:0

BC_EN

Only available in USB251xB/Bi hub family products.

 

 

Battery Charging Enable: Enables the battery charging feature for the

 

 

corresponding port.

 

 

'0' = Battery Charging support is not enabled

 

 

'1' = Battery charging support is enabled

 

 

Bit 7= Reserved

 

 

Bit 6= Reserved

 

 

Bit 5= Reserved

 

 

Bit 4= Controls Port 4

 

 

Bit 3= Controls Port 3

 

 

Bit 2= Controls Port 2

 

 

Bit 1= Controls Port 1

 

 

Bit 0= Reserved

 

 

 

8.2.1.27Register F6h: Boost_Up

BIT

 

 

 

 

NUMBER

 

BIT NAME

DESCRIPTION

 

 

 

 

 

 

7:2

 

Reserved

Reserved

 

 

 

 

 

1:0

 

BOOST_IOUT

USB electrical signaling drive strength Boost Bit for the Upstream Port.

 

 

 

‘00’ = Normal electrical drive strength = No boost

 

 

 

 

‘01’ = Elevated electrical drive strength = Low (~ 4% boost)

 

 

 

‘10’ = Elevated electrical drive strength = Medium (~ 8% boost)

 

 

 

‘11’ = Elevated electrical drive strength = High (~12% boost)

 

 

 

Note: “Boost” could result in non-USB Compliant parameters, OEM

 

 

 

should use a ‘00’ value unless specific implementation issues

 

 

 

require additional signal boosting to correct for degraded USB

 

 

 

signalling levels.

 

 

 

 

 

 

SMSC USB251x

 

45

Revision 1.0 (3-11-09)

DATASHEET