ST25TA64K Datasheet, PDF (15/45 Pages) STMicroelectronics – NFC Forum Type 4 Tag IC with 64-Kbit EEPROM

ST25TA64K
ST25TA64K memory management
3.2.3
Changing the write access right to NDEF files
The state diagram on Figure 3 shows how to change the write access right to an NDEF file.
Figure 3. Changing the write access right to an NDEF file
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1. See the procedure to lock the write access.
2. See the procedure to unlock the write access.
3. See the procedure to permanently lock the write access (Section 7.6: Reaching the read-only state for an
NDEF file).
4. Proprietary state, not defined by NFC Forum Type 4 Tag.
Access right life time
The access right life time is validated while the NDEF file is selected or until the end of the
RF session. Once the read or write access right is granted, the host can send one or more
ReadBinary or UpdateBinary commands.
At the end of a session or when the host selects another file, the read and write access
rights are initialized.
NDEF file passwords
The NDEF file passwords protect the read or write access from an RF interface from/to an
NDEF file.
Two NDEF file passwords are available for each NDEF file:
• Read password
• Write password
The length of a password is 128 bits (16 bytes).
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