DS2252T
DS2252T
Secure Microcontroller Module
FEATURES
PACKAGE OUTLINE
• 8051 compatible microcontroller for secure/sensitive
applications
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32K, 64K, or 128K bytes of nonvolatile SRAM
for program and/or data storage
1
20
21
40
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In–system programming via on–chip serial port
Capable of modifying its own program or data
memory in the end system
40-Pin SIMM
• Firmware Security Features:
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Memory stored in encrypted form
Encryption using on–chip 64–bit key
Automatic true random key generator
SDI Self Destruct Input
DESCRIPTION
The DS2252T is an 8051 compatible microcontroller
based on nonvolatile RAM technology. It is designed for
systems that need to protect memory contents from dis-
closure. This includes key data, sensitive algorithms,
andproprietaryinformationofalltypes. Likeothermem-
bers of the Secure Microcontroller family, it provides full
compatibility with the 8051 instruction set, timers, serial
port, and parallel I/O ports. By using NVRAM instead of
ROM, the user can program, then reprogram the micro-
controller while in–system. This allows frequent chang-
ing of sensitive processes with minimal effort. The
DS2252T provides an array of mechanisms to prevent
an attacker from examining the memory. It is designed
to resist all levels of threat including observation, analy-
sis, and physical attack. As a result, a massive effort
would be required to obtain any information about
memory contents. Furthermore, the “Soft” nature of the
DS2252T allows frequent modification of secure
information. This minimizes that value of any informa-
tion that is obtained.
Improved security over previous generations
Protects memory contents from piracy
• Crashproof Operation
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Maintains all nonvolatile resources for over 10
years in the absence of power
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Power–fail Reset
Early Warning Power–fail Interrupt
Watchdog Timer
Precision reference for power monitor
• Fully 8051 Compatible
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128 bytes scratchpad RAM
Two timer/counters
On–chip serial port
32 parallel I/O port pins
• Permanently powered real time clock
ECopyright 1995 by Dallas Semiconductor Corporation.
All Rights Reserved. For important information regarding
patents and other intellectual property rights, please refer to
Dallas Semiconductor data books.
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