AN3002 datasheet(12/22 Pages) STMICROELECTRONICS

12 / 22 page

RF password mechanisms

AN3002

12/22

Doc ID 15912 Rev 2

A Lock-sector Password command sent to a locked sector returns an error code.

Present-sector Password

The Present-sector Password command is used to present one of the three passwords to

the M24LRxx in order to modify the access rights of all the memory sectors linked to that

password (Table 5) including the password itself. If the presented password is correct, the

access rights remain activated until the tag is powered off or until a new Present-sector

Password command is issued. If the presented password value is not correct, all the access

rights of all the memory sectors are deactivated.

Sector security status byte area access conditions in I2C mode

In I2C mode, read access to the Sector security status byte area is always allowed. Write

access depends on the correct presentation of the I2C password (see I2C Present

Password command description).

To access the Sector security status byte area, the device select code used for any I2C

command must have the E2 Chip Enable address at 1.

An I2C write access to a Sector security status byte re-initializes the RF access condition to

the given memory sector.

AN3002 Datasheet(PDF) 12 Page - STMicroelectronics