2.2.1.6 MAC Address

The IEEE MAC address is part of the device certificate as a Subject Alternative Name (SAN) serial number object. The MAC address adheres to the IEEE EUI-48 standard for MAC addresses. This address is a unique identifier for LAN, WiFi or Bluetooth networks. This value is programmed into the ATECC608B-TNGTLS during device provisioning. The MAC address is a 6 byte (48-bit) value. It is stored as ASCII Hex characters in the first 12 bytes of the data slot.

MAC EUI-48 Example

The EUI-48 value is represented as 6-bytes of hex separated by a dash.
The individual hex digits are interpreted as ASCII Characters
Each of these characters are then translated to their actual ASCII hexadecimal code. So a 6-byte hexadecimal value will convert to a 12-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 ASCII Conversion
Hex / ASCII Char	ASCII Code		Hex / ASCII Char	ASCII Code
Hex / ASCII Char	DEC	HEX	Hex / ASCII Char	DEC	HEX
“0”	48	0x30	“8”	56	0x38
“1”	49	0x31	“9”	57	0x39
“2”	50	0x32	“A”	65	0x41
“3”	51	0x33	“B”	66	0x42
“4”	52	0x34	“C”	67	0x43
“5”	53	0x35	“D”	68	0x44
“6”	54	0x36	“E”	69	0x45
“7”	55	0x37	“F”	70	0x46

Table 2-4. MAC EUI-48 Example (34-C8-CE-AD-21-60)
	Byte 0		Byte 1		Byte 2		Byte 3		Byte 4		Byte 5
ASCII Char	3	4	C	8	C	E	A	D	2	1	6	0
ASCII Code(DEC)⁽¹⁾	51	52	67	56	67	69	65	68	50	49	54	48
ASCII Code(HEX)⁽¹⁾	33	34	43	38	43	45	41	44	32	31	36	30

Note: (1) This is the actual 12-byte value stored in the data slot that represents the MAC IEEE EUI-48 Identifier.