ST25TA02K datasheet(14/50 Pages) STMICROELECTRONICS

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ST25TA02K memory management

ST25TA02K

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DocID027801 Rev 1

An NDEF file can be permanently locked for read or write accesses. Thus, the host cannot

access the NDEF file.

The read password shall be sent to the ST25TA02K device before reading a read-locked

NDEF file.

The write password shall be present on the ST25TA02K device before writing a write-locked

NDEF file. The write password shall be sent to change the read or write access. The read or

write access right is defined for the NDEF file.

3.2.1

State of the Read and Write access rights

Two bytes in the CC file are used to define the Read and Write access rights to the NDEF

file. For more details, refer to Section 3.1.2: CC file layout.

The state 0xFF and 0xFE cannot be changed by using the Read or Write passwords.

3.2.2

Changing the read access right to NDEF files

The state diagram on Figure 2 shows how to change the access right to read an NDEF file.

Table 8. Read access right

Value

Meaning

0x00

Read access without any security

0x80

Locked (1)

1. The read password shall be sent before reading in the NDEF file.

0xFE

Read not authorized

Table 9. Write access right

Value

Meaning

0x00

Write access without any security

0x80

Locked (1)

1. The write password shall be sent before writing in the NDEF file.

0xFF

Write not authorized

ST25TA02K Datasheet(PDF) 14 Page - STMicroelectronics