Datasheet
High Performance Single-Chip 10/100 Non-PCI Ethernet Controller
Datasheet
Revision 1.5 (07-11-08) 98 SMSC LAN9118
DATASHEET
5.4.3 ADDRL—MAC Address Low Register
The MAC Address Low register contains the lower 32 bits of the physical address of the MAC. The
contents of this register are optionally loaded from the EEPROM at power-on through the EEPROM
Controller if a programmed EEPROM is detected. The least significant byte of this register (bits [7:0])
is loaded from address 0x01 of the EEPROM. The most significant byte of this register is loaded from
address 0x04 of the EEPROM. Please refer to Section 4.6 for more information on the EEPROM.
Table 5.7 below illustrates the byte ordering of the ADDRL and ADDRH registers with respect to the
reception of the Ethernet physical address. Also shown is the correlation between the EEPROM
addresses and ADDRL and ADDRH registers.
As an example, if the desired Ethernet physical address is 12-34-56-78-9A-BC, the ADDRL and
ADDRH registers would be programmed as shown in Figure 5.2. The values required to automatically
load this configuration from the EEPROM are also shown.
Figure 5.2 Example ADDRL, ADDRH and EEPROM Setup
Note: By convention, the left most byte of the Ethernet address (in this example 0x12) is the most
significant byte and is transmitted/received first.
Offset: 3 Attribute: R/W
Default Value: FFFFFFFFh Size: 32 bits
BITS DESCRIPTION
31-0 Physical Address [31:0]. This field contains the lower 32 bits (31:0) of the Physical Address of the
LAN9118 device. The content of this field is undefined until loaded from the EEPROM at power-on.
The host can update the contents of this field after the initialization process has completed.
Table 5.7 ADDRL, ADDRH and EEPROM Byte Ordering
EEPROM ADDRESS ADDRN
ORDER OF RECEPTION ON
ETHERNET
0x01 ADDRL[7:0] 1
st
0x02 ADDRL[15:8] 2
nd
0x03 ADDRL[23:16] 3
rd
0x04 ADDRL[31:24] 4
th
0x05 ADDRH[7:0] 5
th
0x06 ADDRH[15:8] 6
th
0x12
07
0x34
815
0x56
1623
0x78
2431
ADDRL
0x9A
07
0xBC
815
ADDRH
xx
1623
xx
2431
0xA5
0x12
0x34
0x56
0x78
0x9A
0xBC
0x00
0x01
0x02
0x03
0x04
0x05
0x06
EEPROM