AT88SC0104CA-TH Atmel, AT88SC0104CA-TH Datasheet - Page 14

• Manufacturer Part Number: AT88SC0104CA-TH
• Description: IC EEPROM 1KBIT 4MHZ 8TSSOP
• Manufacturer: Atmel
• Series: CryptoMemory®r

Specifications of AT88SC0104CA-TH

• Format - Memory: EEPROMs - Serial
• Memory Type: EEPROM
• Memory Size: 1K (128 x 8)
• Speed: 4MHz
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12.5.
12.6.
12.7. Supervisor Mode
12.8.
12.9.
14
Cryptographic Message Authentication Codes
AT88SC0104CA implements a data validity check function in the standard, authentication or encryption modes of
operation.
In the standard mode, data validity check is done through a Modification Detection Code (MDC), in which the host may
read an MDC from the device in order to verify that the data sent was received correctly.
In authentication and encryption modes, the data validity check becomes more powerful since it provides a bidirectional
data integrity check and data origin authentication capability in the form of a Message Authentication Codes (MAC).
Only the host/device that carried out a valid authentication is capable of computing a valid MAC. While operating in the
authentication or encryption modes, the use of MAC is required. For an ingoing command, if the device calculates a
MAC different from the MAC transmitted by the host, not only is the command abandoned but the security privilege is
revoked. A new authentication and/or encryption activation will be required to reactivate the MAC.
Encryption
The data exchanged between the device and the host during read, write and verify password commands may be
encrypted to ensure data confidentiality.
The issuer may choose to require encryption for a user zone by settings made in the configuration memory. Any one of
four keys may be selected for use with a user zone. In this case, activation of the encryption mode is required in order
to read/write data in the zone and only encrypted data will be transmitted. Even if not required, the host may still elect
to activate encryption provided the proper keys are known.
Enabling this feature allows the holder of one specific password to gain full access to all eight password sets, including
the ability to change passwords.
Modify Forbidden
No write access is allowed in a user zone protected with this feature at any time. The user zone must be written during
device personalization prior to blowing the security fuses.
Program Only
For a user zones protected by this feature, data can only be programmed (bits change from a “1” to a “0”), but not
erased (bits change from a “0” to a “1”).
AT88SC0104CA
5200ES–CRYPT–08/09