ST25TA02K Datasheet, PDF (32/50 Pages) STMicroelectronics – NFC Forum Type 4 Tag IC with 2-Kbit EEPROM

RF command sets
ST25TA02K
5.7
5.7.1
ISO/IEC 7816-4 commands
The ISO/IEC 7816-4 command set offers some extended features such as the protection of
the NDEF file. This command set is used to manage the right access of the NDEF file.
Verify command
The Verify command has two functions:
1. Check if a password is required to access to the NDEF file (the LC field = 0x00).
2. Check that the password embedded in the Verify command allows the access to the
memory (the Lc field = 0x10 and the password is present).
When the Lc field if equal to 0x00, the verify command returns a success code (0x90 00)
provided that the access to the NDEF file does not require a password. When the access to
the NDEF file is protected, the response to the Verify command returns an error code
(0x63 00).
When the Lc field equals 0x10, on receiving the Verify command, the ST25TA02K compares
the requested password with the data contained in the request and reports whether the
operation has been successful in the response.
Before sending this command, an NDEF file shall be selected by issuing the NDEF Select
command. Thus, this command checks the right access condition of the last NDEF file
selected.
After a successful command, an access is granted for the whole NDEF file.
Table 34 defines the Verify command.
Table 34. Verify command format
Name
CLA
INS
P1 & P2
Lc
Data
Le
-
0x00
0x20
2 bytes
1 byte
Lc bytes
-
Class byte
Instruction code
Password identification
0x0001: Read NDEF password transmit
0x0002: Write NDEF password transmit
Other: RFU⁽¹⁾
0x00: the password is not present
0x10: the password is present in the data field
Password
(empty field)
1. Return ERROR code when used.
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