AT88SA100S-SH-CZ-T ATMEL [ATMEL Corporation], AT88SA100S-SH-CZ-T Datasheet - Page 13

• Manufacturer Part Number: AT88SA100S-SH-CZ-T
• Description: Atmel CryptoAuthentication Battery Authentication Chip
• Manufacturer: ATMEL [ATMEL Corporation]

6.1
MAC
Computes a SHA-256 digest of the key, challenge and other fixed information on the chip to generate an output response. If
MemValid is not set, indicating that no valid key is stored in the SRAM, then this command will return an error. The hashed
message includes the following bytes, concatenated in this order:
Table 6-1.
Table 6-2.
Table 6-3.
Opcode
Param1
Param2
Data
Name
Response
Bit
6
0-5, 7
256-bits
256-bits
255-bits
16-bits
88-bits
32-bits
16-bits
16-bits
64-bits
8-bits
8-bits
8-bits
1-bit
Input Parameters
Output Parameters
Mode Encoding
Name
MAC
Mode
Zero
Challenge
Notes
If set, then the four bytes of Fuse SN and the two bytes of ROM SN will be included in the message,
otherwise these bits will be set to zero in the message
Ignored, must be all zero
Size
32
Key (Stored in Sram)
Challenge
Opcode (always 0x08)
Mode input
Param2 input
All zeros
Fuse MfrID (Fuse[88-95])
Fuse SN (Fuse[96-127]) or zeros
ROM MfrID
ROM SN or zeros
1’s – SHA-256 padding
0’s – SHA-256 padding
Length (704) per SHA-256
Notes
SHA-256 digest
Size
32
1
1
2
Notes
0x08
See Table 6-6
Must be 0x0000
Input portion of message to be digested
Atmel AT88SA100S [DATASHEET]
8558F−CRYPTO−9/11
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