SMSC LAN9512 - Manual (Page 32)

USB Hub with Integrated 10/100 Ethernet Controller
Datasheet
Revision 1.0 (04-20-09) 32 SMSC LAN9512
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 the device. In
this case, the hardware default values are used, as shown in
Table 3.10 .
3.3 EEPROM Auto-Load
Certain system level resets (USB reset, POR, nRESET, and SRST) cause the EEPROM contents to
be loaded into the device. 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 the external Serial EEPROM is configured for auto-loading. If a value other than 0xA5 is
read from the first address, the EEPROM auto-load will not commense.
Note: The EEPROM contents are loaded for both the Hub and the Ethernet Controller as a result of
a POR or nRESET. The USB reset results only in the loading of the MAC address from the
EEPROM. A software reset (SRST) or a EEPROM Reload Command causes the EEPROM
contents related solely to the Ethernet Controller to be loaded.
Table 3.10 EEPROM Defaults
FIELD DEFAULT VALUE
Ethernet Controller
MAC Address
FFFFFFFFFFFFh
Ethernet Controller
Full-Speed Polling
Interval (mS)
01h
Ethernet Controller
Hi-Speed Polling Interval
(mS)
04h
Ethernet Controller
Configuration Flags
05h
Ethernet Controller
Maximum Power (mA)
01h
Ethernet Controller
Vendor ID
0424h
Ethernet Controller
Product ID
EC00h