4442IC card is a kind of contact IC card, at present, 4442IC card chip mainly has SLE5542, BL7442, FM4442, ISSI4442 several kinds, these kinds of chip structure and usage is exactly the same, can be compatible with each other.
●256-byte EEPROM organization method
●32-bit protection memory composition method
●3-byte user password, password error count: 3 times
Temperature range: 0℃--70℃
●At least 100,000 times erasure
●At least 10 years data retention period
Minimum write/erase time: 2.5ms
●Operating voltage: 5V
Maximum power supply current: 10mA
Factory cured user code 32 bytes write protected data area
1, write protection zone (the first 32 bytes) of each byte can be individually write protection, write protection, the content can no longer be changed (i.e., solid data)
2、All data can be read before the password is verified correctly, if necessary, the data can be properly encrypted.
3、After checking the password is correct, it can be written or modified.
4、Three bytes of the user password can be changed after the verification is correct, effective until the card is powered down.
If the counter value is 0, the card will be locked automatically and the data can only be read out and cannot be changed or password checked again; if it is not zero, it can be restored to the initial value if the password is checked correctly once.
6, byte address 0-5, 6-7 factory has been written by the manufacturer before, can not be changed.
The password protection mechanism of 4442IC card decides to check the password, the number of errors can not exceed 3 times, more than 3 times the chip will automatically lock up, lock up the thick chip can only read the card, can not change the data inside.