DS5002FP

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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

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 #

DESCRIPTION

DS5002FP-16

80-pin QFP,

Max. clock speed 16 MHz,

0°C to 70°C operation

DS5002FPM-16

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.