DS5002FP_1 Datasheet, PDF (2/29 Pages) Dallas Semiconductor – Secure Microprocessor Chip

DS5002FP
The DS5002FP implements a security system which is an improved version of its predecessor, the
DS5000FP. Like the DS5000FP, the DS5002FP loads and executes application software in encrypted
form. Up to 128 kbytes of standard SRAM can be accessed via its byte-wide bus. This RAM is converted
by the DS5002FP into lithium-backed nonvolatile storage for program and data. Data is maintained for
over 10 years at room temperature with a very small lithium cell. As a result, the contents of the RAM
and the execution of the software appear unintelligible to the outside observer. The encryption algorithm
uses an internally stored and protected key. Any attempt to discover the key value results in its erasure,
rendering the encrypted contents of the RAM useless.
The Secure Microprocessor Chip offers a number of major enhancements to the software security
implemented in the previous generation DS5000FP. First, the DS5002FP provides a stronger software
encryption algorithm which incorporates elements of DES encryption. Second, the encryption is based on
a 64-bit key word, as compared to the DS5000FP’s 40-bit key. Third, the key can only be loaded from an
on-chip true random number generator. As a result, the true key value is never known by the user. Fourth,
a Self-Destruct Input pin (SDI) is provided to interface to external tamper detection circuitry. With or
without the presence of V_CC, activation of the SDI pin has the same effect as resetting the Security Lock:
immediate erasure of the key word and the 48-byte Vector RAM area. Fifth, an optional top-coating of
the die prevents access of information using microprobing techniques. Finally, customer-specific versions
of the DS5002FP are available which incorporate a one-of-a-kind encryption algorithm.
When implemented as a part of a secure system design, a system based on the DS5002FP can typically
provide a level of security which requires more time and resources to defeat than it is worth to
unauthorized individuals who have reason to try. For a user who wants a preconstructed module using the
DS5002FP, RAM, lithium cell, and a real time clock, the DS2252T is available and described in a
separate data sheet.
ORDERING INFORMATION
The following devices are available as standard products from Dallas Semiconductor:
PART #
DS5002FP-16
DS5002FPM-16
DESCRIPTION
80-pin QFP,
Max. clock speed 16 MHz,
0°C to 70°C operation
80-pin QFP,
Max. clock speed 16 MHz,
0°C to 70°C operation,
Internal microprobe shield
Operating information is contained in the User’s Guide Section of the Secure Microprocessor Data Book.
This data sheet provides ordering information, pin-out, and electrical specifications.
BLOCK DIAGRAM
Figure 1 is a block diagram illustrating the internal architecture of the DS5002FP. The DS5002FP is a
secure implementation of the DS5001FP 128k Soft Microprocessor Chip. As a result, It operates in an
identical fashion to the DS5001FP except where indicated. See the DS5001FP Data Sheet for operating
details.
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