SLE 4442 M3.2

Application Specific Microcontrollers Overview

The Infineon SLE 4442 M3.2 is an intelligent 256-byte EEPROM designed for chip card applications, featuring a two-wire synchronous interface compliant with ISO 7816-3. It includes 256 bytes of main memory and a 4-byte security memory containing a Programmable Security Code (PSC) and error counter. The device supports byte-wise addressing and irreversible write protection for the lowest 32 addresses via a 32-bit PROM protection memory. Access to modify data requires successful PSC verification; three failed attempts block further write/erase operations. Programming time is 2.5 ms per byte.

Application Specific Microcontrollers Feature Summary

• 256 x 8-bit EEPROM main memory with byte-wise addressing
• Programmable Security Code (PSC) logic requiring verification for write access
• Irreversible write protection for the first 32 bytes using 32-bit PROM protection memory
• Two-wire link protocol compliant with ISO standard 7816-3

Application Specific Microcontrollers Applications

• Smart cards requiring secure data storage
• Identity documents with programmable security features
• Access control systems utilizing PSC verification

Application Specific Microcontrollers Procurement Notes

Verify that the specific ordering suffix corresponds to the required package type, as the datasheet lists M2.2 wire-bonded modules and die options. Confirm that the necessary license for smart card application usage from INNOVATRON Patents is secured separately, as it is not included with the component supply. Ensure compatibility with the customer's AID programming requirements if applicable.

Application Specific Microcontrollers Selection Notes

Select the SLE 4442 over the SLE 4432 when active security code verification is required to prevent unauthorized data modification. The SLE 4442 adds a security memory block and PSC comparison commands absent in the base model. Consider the irreversible nature of the protection memory bits and the error counter limitations when designing the access control logic.

Application Specific Microcontrollers Part Context

The SLE 4442 is part of the Siemens/Infineon SLE 44xx series of intelligent EEPROMs for chip cards. It shares the same physical interface and basic memory organization as the SLE 4432 but extends functionality with security features. The M3.2 designation typically refers to a specific packaging or coding variant within this family, often associated with wire-bonded modules for embedding in plastic cards.

Application Specific Microcontrollers Replacement Considerations

The SLE 4432 serves as a functional baseline without security features. Direct replacements must support the ISO 7816-3 two-wire protocol and 256-byte capacity. Verify that any substitute component offers equivalent PSC verification logic and irreversible protection capabilities if security is critical.

Application Specific Microcontrollers FAQ

How does the SLE 4442 protect against unauthorized writes?

It uses a Programmable Security Code (PSC) stored in security memory. Write access is blocked until the correct PSC is verified through a specific command sequence. Three failed verification attempts lock the error counter, preventing further modifications.

Can the write protection for the first 32 bytes be reversed?

No. The protection memory consists of PROM bits. Once a protection bit is written to enable write protection for a specific address, it cannot be erased or changed back.

What happens if the RST line is set high during a clock low level?

This triggers a 'Break' condition. Any ongoing operation is aborted, and the I/O pin is switched to high impedance Z. The chip then becomes ready for new operations after a valid reset.