ST19XS08

2/4

HARDWARE DESCRIPTION

The product, member of the ST19X platform, is a

serial access microcontroller specially designed

for cost effective secure portable applications.

It is manufactured using an advanced highly reli-

able ST CMOS EEPROM technology.

It is based on a STMicroelectronics 8 bit CPU and

includes on-chip memories: User ROM, User RAM

and EEPROM with state of the art security fea-

tures. ROM, RAM and EEPROM memories can be

configured into partitions with customized access

rules.

An additional ST ROM contains all ST provided

functions and libraries.

Access from any memory area to another are pro-

tected by hardware FIREWALLS. Access rules are

User defined and can be selected by mask op-

tions.

The chip includes a DES accelerator which is ac-

cessible via cryptographic software libraries locat-

ed in ST ROM.

As with all the other ST19X products, a serial inter-

face fully compatible with the ISO7816 standard

for Smartcard applications is available.

A CRC calculation block is also available and is di-

rectly accessible by the User.

Figure 2. Block Diagram

INTERNAL BUS

I/O

1 X

SERIAL

INTER-

FACE

GND

8 BIT

CPU

2 X

8 BIT

TIMERS

CRC

MODULE

CLK

CLOCK

GENE-

RATOR

MODULE

Vcc

GUN A

&

GUN B

RAM

USER ROM

ST ROM and

DES LIBRARY

349

SECU-

RITY

ADMIN.

RESET

EEPROM

ST ROM

and DES FIREWALL

MEMORY ACCESS FIREWALL

DES

ACCELE-

RATOR