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ST22N256

DESCRIPTION

The ST22N256 is a member of the SmartJ™ plat-

form using a 32-bit Reduced Instruction Set Com-

puter (RISC) core to execute both Native RISC

instructions and JavaCard™ 2.x Technology in-

struction (byte codes) directly.

Direct JavaCard™ byte code execution provides

high performance advantage over processors that

emulate the JavaCard™ byte code instruction set.

The product features a 24-bit wide linear address-

ing capability and includes User ROM, User RAM,

and User EEPROM.

Memory and Peripheral accesses are controlled

by a Memory Protection Unit that allows to imple-

ment firewalls between applications.

Memories are accessed via two different buses,

allowing simultaneous accesses to code and data.

Memory load and stores can be performed at byte,

short (2-bytes), or word (4-bytes) granularity, with

optional pointer auto increment.

The ST22 core includes dedicated DES instruc-

tions for Secret Key cryptography, and a fast Mul-

tiply and Accumulate instruction for Public Key

cryptography (RSA) and Elliptic Curve cryptogra-

phy, and a CRC instruction. The ST22 core also

includes specific instructions for security.

The product has clock and power management, 2

User configurable Timers, a Central Interrupt Con-

troller and a Random Number Generator.

Figure 2. SmartJ™ Platform EEPROM Architecture

POWER MANAGEMENT

32-bit

RISC

CORE

CLOCK MANAGEMENT

MPU

RAM

BUS 2

BUS 1

PERIPHERALS

ISO

7816

ROM

EEPROM