The memory can be secured by using the 32 bit password for all write and read protected operations. The password can be updated, but never read. The fixed code serial number and device identification are laser programmed making every chip unique.
The TK4100 will transmit data to the transceiver by modulating the amplitude of the electromagnetic field, and receive data and commands in a similar way. Simple commands will enable to write EEPROM, to update the password, to read a specific memory area, and to reset the logic. The coil of the tuned circuit is the only external component required, all remaining functions are integrated in the chip.