E5561_06 Datasheet, PDF (1/28 Pages) ATMEL Corporation – Standard Read/Write Crypto Identification IC

Features
• Low-power, Low-voltage CMOS IDIC^®
• Contactless Power Supply, Data Transmission and Programming of EEPROM
• Radio Frequency (RF): 100 kHz to 150 kHz, Typically 125 kHz
• Programmable Adaptation of Resonance Frequency
• Easy Synchronization with Special Terminators
• High-security Method Unilink Challenge Response Authentication by AUT64 Crypto
Algorithm
• Encryption Time < 10 ms, Optional < 30 ms Programmable at 125 kHz
• 320-bit EEPROM Memory in 10 Blocks of 32 Bits Each
• Programmable Read/Write Protection
• Extensive Protection Against Contactless Malprogramming of the EEPROM
• Programming Time for One Block of the EEPROM Typically 16 ms
• Main Options Set by EEPROM:
– Bit Rate [Bit/s]: RF/32, RF/64
– Encoding: Manchester, Bi-phase
Standard
Read/Write
Crypto
Identification IC
1. Description
The e5561 is a member of Atmel^®’s IDentification IC (IDIC) family for applications
where information has to be transmitted contactlessly. The IDIC is connected to a
tuned LC circuit for power supply and bi-directional data communication (Read/Write)
to a base station. Atmel offers an LC circuit and a chip assembled in the form of a
transponder or tag. These units are small, smart and rugged data storage units.
The e5561 is a Read/Write crypto IC for applications which demand higher security
levels than standard R/W transponder ICs can offer. For that purpose, the e5561 has
an encryption algorithm block which enables a base station to authenticate the tran-
sponder. The base station transmits a random number to the e5561. This challenge is
encrypted by both IC and base station. The e5561 sends back the result to the base
station for comparison. As both should possess the same secret key, the results of
this encryption are expected to be equal. Any attempt to fake the base station with a
wrong transponder will be recognized immediately.
The on-chip 320-bit EEPROM (10 blocks of 32 bits each) can be read and written
blockwise by a base station. Two or four blocks contain the ID code and six memory
blocks are used to store the crypto key as well as the read/write options. The crypto
key and the ID code can be protected individually against overwriting. Likewise, the
crypto key cannot be read out.
125 kHz is the typical operational frequency of a system using the e5561. Two read
data rates are programmable. Reading occurs through damping the incoming RF field
with an on-chip load. This damping is detected by the field-generating base station.
Data transmission starts after power-up with the transmission of the ID code and con-
tinues as long as the e5561 is powered. Writing is carried out with Atmel's writing
method. To transmit data to the e5561, the base station has to interrupt the RF for a
short time to create a field gap. The information is encoded in the number of clock
cycles between two subsequent gaps.
e5561
4699D–RFID–09/06