DESCRIPTION

The X76F640 is a Password Access Security Supervisor, containing one 65536-bit Secure SerialFlash array and one 256-bit Secure SerialFlash array. Access to each memory array is controlled by two 64-bit passwords. These passwords protect read and write operations of the memory array. A separate RESET password is used to reset the passwords and clear the memory arrays in the event the read and write passwords are lost.

The X76F640 features a serial interface and software protocol allowing operation on a popular two wire bus. The bus signals are a clock Input (SCL) and a bidirec tional data input and output (SDA). Access to the device is controlled through a chip select (CS) input, allowing any number of devices to share the same bus.

The X76F640 also features a synchronous response to reset providing an automatic output of a hard-wired 32-bit data stream conforming to the industry standard for memory cards.

The X76F640 utilizes Xicor’s proprietary Direct WriteTM cell, providing a minimum endurance of 100,000 cycles and a minimum data retention of 100 years.

FEATURES

• 64-bit Password Security

—Five 64-bit Passwords for Read, Program and Reset

• 8192 Byte+32 Byte Password Protected Arrays

—Seperate Read Passwords

—Seperate Write Passwords

—Reset Password

• Programmable Passwords

• Retry Counter Register

—Allows 8 tries before clearing of both arrays

—Password Protected Reset

• 32-bit Response to Reset (RST Input)

• 32 byte Sector Program

• 400kHz Clock Rate

• 2 wire Serial Interface

• Low Power CMOS

—2.7 to 5.5V operation

—Standby current Less than 1µA

—Active current less than 3 mA

• High Reliability Endurance:

—100,000 Write Cycles

• Data Retention: 100 years

• Available in:

—8 lead SOIC

—SmartCard Module