ATAES132-TH-EQ Atmel, ATAES132-TH-EQ Datasheet - Page 39

• 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

7.9.
7.9.1.
7.9.2.
EncRead Command
EncRead reads 1 to 32 bytes of encrypted data from user memory, along with an integrity MAC. The EncRead command only
performs encrypted reads; the BlockRead command is used for unencrypted reads (see Section 7.4).
The ZoneConfig[UZ].EncRead bit determines if a user zone can be accessed with the EncRead command. If the
ZoneConfig[UZ].EncRead bit is 1b, then the EncRead command can read the user zone if the access requirements have been
satisfied. A single EncRead command reads data from a single user zone – the requested data can not span multiple user
zones. A single EncRead command reads data from a single EEPROM page – the requested data can not cross page
boundaries (see Section B.2).
If ZoneConfig[UZ].Auth is 1b, then prior authentication is required with the following restrictions:
The DecRead command can be used to validate the OutMac and decrypt up to 16 bytes of data (see Section 7.7).
Configuration Memory Signature
The EncRead command cannot be used to read the configuration memory – the BlockRead command can be used to read the
configuration memory. Any attempt to read any address in the configuration memory with the EncRead command will activate
the configuration memory signature generation mode.
The configuration memory signature is an AES-CCM MAC generated over the entire configuration memory as described in
Section I.17. A valid nonce is required to run the EncRead command in configuration memory signature generation mode. If
KeyConfig[00].RandomNonce is 1b, then the nonce must be random. KeyID 00 is always used to generate the configuration
memory signature.
The configuration memory signature generation mode is intended to be used during secure personalization of the ATAES132.
The signature can be used to validate the contents of the configuration memory prior to programming secret data into other
portions of the EEPROM.
Key Memory Signature
The EncRead command cannot be used to read the key memory. The key memory can never be read. Any attempt to read
any address in the key memory with the EncRead command will activate the key memory signature generation mode;
however, this signature can only be generated once per unit.
The key memory signature is an AES-CCM MAC generated over all 16 key registers as described in Section I.18. A valid
nonce is required to run the EncRead command in key memory signature Generation mode. If KeyConfig[00].RandomNonce
is 1b, then the nonce must be random. KeyID 00 is always used to generate the key memory signature.
The key memory signature generation mode is intended to be used during secure personalization of the ATAES132. The
signature can be used to validate the contents of the key memory before locking the key memory.
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The Auth command Usage.ReadOK bit must be 1b
The authentication key AKeyID must match ZoneConfig[UZ].AuthID
The Auth command must be run in Inbound Only Authentication or Mutual Authentication mode
A valid Nonce is required to run the EncRead command. If KeyConfig[KeyID].RandomNonce for the Read key is 1b,
then the Nonce must be random.
Atmel ATAES132 Preliminary Datasheet
8760A−CRYPTO−5/11
39