2.2.1.2 IEEE EUI-64 Identifier

The IEEE Extended Unique Identifier (EUI) is an 8-byte binary or hexadecimal value, which in this case, is used as a Device EUI to uniquely identify a LoRaWAN node. This globally unique Device EUI (DevEUI) is assigned and written into Slot 10 of the ATECC608A-TNGLoRaWAN. The DevEUI would be part of the reconstructed X.509 Certificate. For the ATECC608A-TNGLoRaWAN the IEEE EUI will be assigned by Microchip.

For the ATECC608A-TNGLoRaWAN, the 8-byte DevEUI is actually stored as a 16-byte ASCII-Hex value. Every digit of the hex EUI byte is represented by an ASCII character equivalent to its hexadecimal numerical value.

EUI-64 Identifier Example

  1. The EUI-64 value is specified as an 8-byte hexadecimal value.
  2. The individual hex digits are interpreted as ASCII characters
  3. Each of these characters are then translated to their actual ASCII hexadecimal code. So an 8-byte hexadecimal value will convert to a 16-byte ASCII-Hex value. Note the conversion between the ASCII character and the ASCII code in both decimal and hexadecimal are shown in Table 2-3.
Table 2-3. Hex to ASCII Conversion
Hex / ASCII CharASCII CodeHex / ASCII CharASCII Code
DECHEXDECHEX
“0”480x30“8”560x38
“1”490x31“9”570x39
“2”500x32“A”650x41
“3”510x33“B”660x42
“4”520x34“C”670x43
“5”530x35“D”680x44
“6”540x36“E”690x45
“7”550x37“F”700x46
Table 2-4. DevEUI Conversion Example
Byte 0Byte 1Byte 2Byte 3Byte 4Byte 5Byte 6Byte 7
ASCII CharCB6FD54B423166CD
ASCII Code(DEC)(1)67665470685352665250514954546768
ASCII Code(HEX)(1)43423646443534423432333136364344
Note: (1) This is the actual 16-byte value stored in the data slot that represents the IEEE EUI-64 Identifier.