AT88SA102S_10 ATMEL [ATMEL Corporation], AT88SA102S_10 Datasheet - Page 17

• Manufacturer Part Number: AT88SA102S_10
• Description: Atmel CryptoAuthentication
• Manufacturer: ATMEL [ATMEL Corporation]

5.4.
5.5.
8584F–SMEM–8/10
Table 5-2.
GenPersonalizationKey
Loads a personalization key into internal memory and then uses that key along with an input seed to generate a
decryption digest using SHA-256. Neither the key nor the decryption digest can be read from the chip. Upon
completion, an internal bit is set indicating that a secure personalization digest has been loaded and is ready for
use by BurnSecure. This bit is cleared (and the digest lost) when the watchdog timer expires or the power is
cycled.
This command will fail if Fuse[87] has been burned.
Table 5-1.
Table 5-2.
The SHA-256 message body used to create the resulting digest internally stored in the chip consists of the
following 512-bits:
BurnSecure
Burns any combination of the first 88-fuse bits. Verification that the proper secret fuse bits have been burned must
occur using the MAC command – there is no way to read the values in the first 64-fuses to verify their state. The
24-status fuses can be verified with the Read command.
The fuses to be burned are specified by the 88-bit input map parameter. If a bit in the map is set to a ‘1’, then the
corresponding fuse is burned. If a bit in the map parameter is zero, then the corresponding fuse is left in its
current state. The first bit sent to the Atmel
Note:
Name
Success
Opcode
Param1
Param2
Data
Name
Success
Since a ‘1’ bit in the Map parameter results in a ‘0’ data value in the actual fuse array, the value in the Map parameter
should generally be the inverse of the desired secret or status value. See Section 1.3 for more details.
256-bits
127-bits
64-bits
64-bits
1-bits
Output Parameters
Input Parameters
Output Parameters
Name
GenPers
Zero
KeyID
Seed
Size
1
Size
1
PersonalizeKey[KeyID]
Fixed value of all ones
Seed from input stream
‘1’ pad
Length of message in bits, fixed at 447
Notes
Upon successful execution, a value of 0 will be returned by the Atmel AT88SA102S
Notes
Upon successful execution of HOST0, a value of 0 will be returned by the Atmel AT88SA102S
Size
16
1
1
2
Notes
0x20
Must be 0x00
Identification number of the personalization key to be loaded
Seed for digest generation. The least significant bit of the last byte is ignored by
the Atmel AT88SA102S
®
AT88SA102S corresponds to Fuse[0] and so on up to Fuse[87].
Atmel AT88SA102S
17