Chip Introduction
This particular series of IC card chip is manufactured by Shanghai FM Co., Ltd. It uses 0.6μm CMOS EEPROM process with 256X8 Bits EEPROM plus programmable security code and write protect function. Having met the ISO standard 7816 (synchronous transmission), this IC card chip is used in different types of IC memory cards.

FM4442 is the memory card chip developed by Shanghai FM Co., Ltd. This chip has 256×8 Bits EEPROM with write protect function and programmable security code. With its contact configuration in accordance to ISO standard 7816 (synchronous transmission), FM4442 can be widely used in different types of IC memory cards.

Feature
• 256×8-bits EEPROM organization
• Byte-wise addressing
• 32×1-bit organization of protection memory
• Irreversible byte-wise write protection of lowest 32 addresses (Byte 0 ... 31)
• Two-wire link protocol • End of processing indicated at data output
• Answer-to-Reset acc. to ISO standard 7816-3
• Data retention for minimum of ten years • Programming time 2.5 ms per byte for both erasing and writing
• Contact configuration and serial interface in accordance with ISO standard 7816 (Synchronous transmission)
• Data can only be changed after entry of the correct 3-byte programmable security code (security memory)
• Compatible SLE4442

Function Description
The FM4442 consists of 256 x 8 bits EEPROM main memory and a 32-bit protection memory with PROM functionality. The main memory is erased and written byte by byte. Each of the first 32 bytes can be irreversibly protected against data change by writing the corresponding bit in the protection memory. Each data byte in this address range is assigned to one bit of the protection memory and has the same address as the data byte in the main memory which it is assigned to. Once written the protection bit cannot be erased (PROM).