SMSC LAN9500 - Manual (Page 22)

Hi-Speed USB 2.0 to 10/100 Ethernet Controller
Datasheet
Revision 1.7 (10-02-08) 22 SMSC LAN9500/LAN9500i
DATASHEET
3.2 EEPROM Defaults
The signature value of 0xA5 is stored at address 0. A different signature value indicates to the
EEPROM controller that no EEPROM or an un-programmed EEPROM is attached to
LAN9500/LAN9500i. In this case, the hardware default values are used, as shown in
Table 3.3 .
Note: The Configuration Flags are affected by the PWR_SEL and RMT_WKP straps.
3.3 EEPROM Auto-Load
Certain system level resets (USB reset, POR, nRESET, and SRST) cause the EEPROM contents to
be loaded into LAN9500/LAN9500i. After a reset, the EEPROM controller attempts to read the first
byte of data from the EEPROM. If the value 0xA5 is read from the first address, then the EEPROM
controller will assume that an external Serial EEPROM is present.
Note: The USB reset only loads the MAC address.
Table 3.3 EEPROM Defaults
FIELD DEFAULT VALUE
MAC Address FFFFFFFFFFFFh
Full-Speed Polling Interval (mS) 01h
Hi-Speed Polling Interval (mS) 04h
Configuration Flags 04h
Maximum Power (mA) FAh
Vendor ID 0424h
Product ID 9500h