USB 2.0 7-Port Hub

Data Sheet Rev. 1.01

The first two bytes are the check code for the existence of EEPROM, their value must be 0x1A40. Any

other value would cause the EEPROM loading mechanism of FE2.1 to conclude that the contents of this

EEPROM is unusable, and use default values instead.

The string descriptor for device's serial number could be defined by Device Serial Number and Length

of Serial Number fields of the EEPROM, address 0x08 to 0x18. Length of Serial Number field, address

0x18, define the number of digits, while Device Serial Number field, address 0x08 to 0x17, specify the

serial number in ASCII code. The space after the specified number of digits should be filled with Null,

0x00. For example, suppose the serial number is “A090108F4”, then the EEPROM should be like:

0x08

0x41 (A) 0x30 (0)

0x39 (9)

0x30 (0)

0x31 (1)

0x30 (0)

0x38 (8)

0x46 (F)

0x10

0x34 (4)

0x00 (Null) 0x00 (Null) 0x00 (Null) 0x00 (Null) 0x00 (Null) 0x00 (Null) 0x00 (Null)

0x18

0x09

The last byte, address 0x1F, is a checksum made up of the sum of all value from 0x00 to 0x1E. The

numbers must match to render the contents of the EEPROM usable. Otherwise, the loading mechanism

of FE2.1 would discard the value from EEPROM and use default values instead.

Jul. 16, 2009

Subject to Change Without Notice

16