ST25DV04K datasheet(57/197 Pages) STMICROELECTRONICS

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Rf blocks 0 and 1 are exceptions to this protection mechanism:

–

RF blocks 0 and 1 can be individually write locked by issuing a (Ext) Lock Single Block RF command.

Once locked, they cannot be unlock through RF. LOCK_CCFILE register is automatically updated

when using (Ext) Lock Single Block command.

–

A RF user needs no password to lock blocks 0 and/or 1.

–

Locking blocks 0 and/or 1 is possible even if the configuration is locked (LOCK_CFG=1).

–

Locking blocks 0 and/or 1 is possible even if the area is write locked.

–

Unlocking area1 (through RFA1SS register) does not unlock blocks 0 and 1 if they have been locked

though (Ext) Lock Block command.

–

Once locked, the RF user cannot unlock blocks 0 and/or 1 (can be done by I2C host).

Note:

When areas size are modified (ENDAi registers), RFAiSS registers are not modified.

User memory protection from I2C access

In I2C mode, each area can also have individual Read/Write access conditions, but only one I2C password is used

to unlock I2C security session for all areas.

The I2CSS register is used to set protection against read and write operation for each area (see Table 52. I2CSS

for details about available read and write protections).

When updating I2CSS registers, the new protection value is effective immediately after the register write

completion.

I2C user memory Bytes 0000h to 0003h (RF Block 0) and 0004h to 0007h (RF Block 1) can be individually locked

and unlocked by writing in the LOCK_CCFILE register (by group of 4 Bytes), independently of Area 1 protection.

Unlocking Area 1 (through I2CSS register) does not unlock those bytes if they have been locked though the

LOCK_CCFILE register.

Note:

When areas size are modified (ENDAi registers), I2CSS register is not modified.

Retrieve the security status of a user memory block or byte

RF user can read a block security status by issuing following RF commands:

•

(Ext) Get Multiple Blocks Security Status command.

•

(Ext) (Fast) Read Single Block with option flag set to 1.

•

(Ext) (Fast) Read Multiple Blocks with option flag set to 1.

ST25DV will respond with a Block security status containing a Lock_bit flag as specified in ISO 15693 standard.

This lock_bit flag is set to one if block is locked against write.

Lock_bit flag value may vary if corresponding RF user security session is open or closed.

I2C host can retrieve a block security status by reading the I2CSS register to get security status of the

corresponding area and by reading the I2C_SSO_Dyn register to know if I2C security session is open or closed.

For blocks 0 and 1 (Bytes 0000h to 0007h in I2C user memory), lock status can also be read in the

LOCK_CCFILE register.

5.6.4

System memory protection

By default, system memory (static registers) is write protected, both in RF and I2C.

I2C host must open the I2C security session (by presenting a valid I2C password) to enable write access to

system configuration static registers.

I2C host doesn’t have read or write access to RF passwords.

By default, I2C host can read all system configuration static registers (except RF passwords)

In RF, to enable write access to system configuration static registers, RF user must open the RF configuration

security session (by presenting a valid RF password 0) and system configuration must not be locked

(LOCK_CFG=00h).

RF doesn’t have read or write access to I2C password.

By default, RF user can read all system configuration static registers, except all passwords, LOCK_CCFILE,

LOCK_DSFID and LOCK_AFI.

RF configuration lock:

ST25DV04K ST25DV16K ST25DV64K

Data Protection

DS10925 - Rev 11

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