at88sc153 ATMEL Corporation, at88sc153 Datasheet - Page 2

• Manufacturer Part Number: at88sc153
• Description: 3 X 64 X 8 Secure Memory With Authentication
• Manufacturer: ATMEL Corporation

Figure 0-2.
1. Description
2. Memory Access
2
AT88SC153
8-pin SOIC or, PDIP
The AT88SC153 provides 2,048 bits of serial EEPROM memory organized as one configuration
zone of 64 bytes and three user zones of 64 bytes each. This device is optimized as a “secure
memory” for multiapplication smart card markets, secure identification for electronic data trans-
fer, or components in a system without the requirement of an internal microprocessor.
The embedded authentication protocol allows the memory and the host to authenticate each
other. When this device is used with a host that incorporates a microcontroller (e.g., AT89C51,
AT89C2051, AT90S1200), the system provides an “anti-wiretapping” configuration. The device
and the host exchange “challenges” issued from a random generator and verify their values
through a specific cryptographic function included in each part. When both agree on the same
result, the access to the memory is permitted.
Figure 1-1.
Depending on the device configuration, the host might carry out the authentication protocol
and/or present different passwords for each operation, read or write. Each user zone may be
configured for free access for read and write or for password-restricted access. To insure secu-
rity between the different user zones (multiapplication card), each zone can use a different set of
passwords. A specific attempts counter for each password and for the authentication provides
protection against “systematic attacks.” When the memory is unlocked, the two-wire serial proto-
col is effective, using SDA and SCL. The memory includes a specific register providing a 32-bit
data stream conforming to the ISO 7816-10 synchronous answer-to-reset.
Security Methodology
GND
SDA
NC
NC
1
2
3
4
8
7
6
5
VCC
RST
SCL
NC
1016E–SMEM–12/07