m24lr64-r STMicroelectronics, m24lr64-r Datasheet - Page 25

• Manufacturer Part Number: m24lr64-r
• Description: 64 Kbit Eeprom With Password Protection & Dual Interface 400 Khz I?c Serial Bus & Iso 15693 Rf Protocol At 13.56 Mhz
• Manufacturer: STMicroelectronics

M24LR64-R
4.3
4.4
I2C_Write_Lock bit area
In the I
This feature is controlled by the I2C_Write_Lock bits stored in the 8 bytes of the
I2C_Write_Lock bit area starting from the location 2048 (see
it is possible to write-protect all the 64 sectors of the M24LR64-R memory.
Each bit controls the I
possible to unprotect a sector in the I
the corresponding sector is unprotected. When the bit is set to 1, the corresponding sector
is write-protected.
In I
depends on the correct presentation of the I
To access the I2C_Write_Lock bit area, the device select code used for any I
must have the E2 Chip Enable address at 1.
On delivery, the default value of the 8 bytes of the I2C_Write_Lock bit area is reset to 00h.
Table 13.
System parameters
The M24LR64-R provides the system area required by the ISO 15693 RF protocol, as
shown in
The first 32-bit block starting from I
is used to activate/deactivate the write protection of the protected sector in I
power-on, all user memory sectors protected by the I2C_Write_Lock bits can be read but
cannot be modified. To remove the write protection, it is necessary to use the I
Password described in
all the presented bits correspond to the stored ones — it is also possible to modify the I
password using the I
The next three 32-bit blocks store the three RF passwords. These passwords are neither
read- nor write- accessible in the I
The next 2 bytes are used to store the AFI, at I
location 2323. These 2 values are used during the RF Inventory sequence. They are read-
only in the I
The next 8 bytes, starting from location 2324, store the 64-bit UID programmed by ST on the
production line. Bytes at I
used by the RF Get_System_Info command. The UID, Mem_Size and IC Ref values are
read-only data.
2
E2 = 1
E2 = 1
C mode, read access to the I2C_Write_Lock bit area is always allowed. Write access
I
2
C byte address
2
C mode only, it is possible to protect individual sectors against Write operations.
Table
2
C mode.
I2C_Write_Lock bit
14.
2048
2052
2
C Write Password command described in
2
C write access to a specific sector as shown in
Figure
2
C locations 2332 to 2335 store the IC Ref and the Mem_Size data
sectors 31-24
sectors 63-56
Bits [31:24]
8. When the password is correctly presented — that is, when
Doc ID 15170 Rev 9
2
2
C mode.
C address 2304 stores the I
2
C mode. When an I2C_Write_Lock bit is reset to 0,
sectors 23-16
sectors 55-48
2
Bits [23:16]
C password.
2
C location 2322, and the DSFID, at I
sectors 47-40
sectors 15-8
Table
Bits [15:8]
2
C password. This password
Figure
13). Using these 64 bits,
System memory area
Table
9.
2
13. It is always
2
sectors 39-32
C mode. At
C command
sectors 7-0
2
Bits [7:0]
C Present
2
C
25/126
2
C