The SLE 4442 provides a secure code logic to control write/erase access to memory. For this purpose, the SLE 4442 contains a 4-byte secure memory with an error counter EC (bits 0 to 2) and 3-byte reference data. These 3 bytes as a whole are called Programmable Security Code (PSC). After the entire memory is powered up, it can only be read except for the reference data. Only after the verification data is successfully compared with the internal reference data, the memory has the same access function as the SLE 4432 until the power is turned off. After three consecutive unsuccessful comparisons, the error counter prevents any subsequent attempts, thus preventing any possibility of writing and erasing.
