ATAES132-TH-EQ Atmel, ATAES132-TH-EQ Datasheet - Page 46

• Manufacturer Part Number: ATAES132-TH-EQ
• Description: EEPROM AES 32Kbit EE SPI
• Manufacturer: Atmel

Specifications of ATAES132-TH-EQ

• Rohs: yes
• Maximum Clock Frequency: 10 MHz
• Operating Supply Voltage: 6 V
• Maximum Operating Temperature: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-8
• Interface Type: SPI
• Factory Pack Quantity: 2300

7.13.
KeyCompute Command
The KeyCompute command generates a 16 byte random number and stores it in either the key memory or in the VolatileKey
register. The newly generated key is then encrypted with the parent key and returned to the host along with a MAC.
If Mode bit 0 is 1b, then the target key is in the key memory:
If Mode bit 0 is 0b, then the target key is VolatileKey:
If KeyConfig[ParentKeyID].AuthKey bit is 1b or KeyConfig[EKeyID].ExportAuth bit is 1b, then prior authentication is required
using the KeyID stored in KeyConfig[ParentKeyID].LinkPointer.
The InMAC and OutMAC are both calculated using the parent key (ParentKeyID). If KeyConfig[ChildKeyID].ChildMac is 1b,
then an InMAC must be provided, otherwise the InMAC will be ignored.
A valid nonce is required to run the KeyCompute command. If the KeyConfig[ParentKeyID].RandomNonce bit is 1b, then the
nonce must be random.
If the LockConfig register is unlocked (0x55), then the random number generator is latched in test mode and the KeyCompute
command will generate non-random key values. If the LockConfig register is locked (0x00), then the RNG generates random
numbers and the KeyCompute command functions normally.
The KeyImport command can be used to load a key generated by the KeyCompute command (see Section 7.15).
Warning:
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KeyConfig[ChildKeyID].Child must be 1b
The KeyCompute command KeyID field contains the ChildKeyID
KeyConfig[ChildKeyID].LinkPointer contains the ParentKeyID
KeyConfig[ParentKeyID].Parent must be 1b
The KeyCompute command KeyID field contains the ParentKeyID
The VolUsage field specifies VolatileKey usage restrictions as defined in Section 4.3
There is one random number generator (RNG) seed register in the EEPROM memory which is used by the
KeyCompute, KeyExport, nonce, and random commands. The RNG seed register is subject to the same
write endurance limitations as the other bytes in the EEPROM (see Section 9.2 for the EEPROM
specifications) – the application developer must not exceed the write endurance limit.
Atmel ATAES132 Preliminary Datasheet
8760A−CRYPTO−5/11
46