24AA256UID Datasheet, PDF (13/28 Pages) Microchip Technology – 256K I2C™ Serial EEPROM

24AA256UID
FIGURE 9-2:
SERIAL NUMBER PHYSICAL MEMORY MAP EXAMPLE
Description
Manufacturer
Code
Device
Code
32-bit Serial Number
Data
29h
48h
12h
34h
56h
78h
Type
Array
Address
Fixed
7FFAh
7FFBh
7FFCh
Serialized
7FFDh
7FFEh
7FFFh
9.2 EUI-48 Node Address
The 6-byte EUI-48 node address value is stored in
array locations 0x7F7A through 0x7F7F, as shown in
Figure 9-3. The first three bytes are the
Organizationally Unique Identifier (OUI) assigned to
Microchip by the IEEE Registration Authority. Currently,
Microchip’s OUIs are 0x0004A3 and 0x001EC0,
though this will change as addresses are exhausted.
The remaining three bytes are the Extension Identifier,
and are generated by Microchip to ensure a globally
unique, 48-bit value.
9.3 EUI-64 Node Address
The 8-byte EUI-64 node address value is stored in
array locations 0x7FB8 through 0x7FBF, as shown in
Figure 9-4. The first three bytes are the
Organizationally Unique Identifier (OUI) assigned to
Microchip by the IEEE Registration Authority. Currently,
Microchip’s OUIs are 0x0004A3 and 0x001EC0,
though this will change as addresses are exhausted.
The remaining five bytes are the Extension Identifier,
and are generated by Microchip to ensure a globally
unique, 64-bit value.
Note:
In conformance with IEEE guidelines,
Microchip will not use the values 0xFFFE
and 0xFFFF for the first two bytes of the
EUI-64 Extension Identifier. These two
values are specifically reserved to allow
applications to encapsulate EUI-48
addresses into EUI-64 addresses.
FIGURE 9-3:
EUI-48 NODE ADDRESS PHYSICAL MEMORY MAP EXAMPLE
Description
24-bit Organizationally
Unique Identifier
Data
00h
04h
A3h
Array
Address
7F7Ah
24-bit Extension
Identifier
12h
34h
56h
7F7Fh
Corresponding EUI-48™ Node Address: 00-04-A3-12-34-56
 2013 Microchip Technology Inc.
DS20005215A-page 13