m24lr64-r STMicroelectronics, m24lr64-r Datasheet - Page 23

• 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
Table 8.
The next 2 bits of the Sector security status byte (b
value these two bits is used to link a password to the sector as defined in
Table 9.
The M24LR64-R password protection is organized around a dedicated set of commands
plus a system area of three password blocks where the password values are stored. This
system area is described in
Table 10.
The dedicated password commands are:
●
●
Sector
Add
Lock
1
2
3
Write-sector Password:
The Write-sector Password command is used to write a 32-bit block into the password
system area. This command must be used to update password values. After the write
cycle, the new password value is automatically activated. It is possible to modify a
password value after issuing a valid Present-sector Password command.
On delivery, the three default password values are set to 0000 0000h and are activated.
Lock-sector Password:
The Lock-sector Password command is used to set the Sector security status byte of
the selected sector. Bits b
Lock-sector Password command. The Sector Lock bit, b
After issuing a Lock-sector Password command, the protection settings of the selected
sector are activated. The protection of a locked block cannot be changed in RF mode.
A Lock-sector Password command sent to a locked sector returns an error code.
0
1
1
1
1
b
4
00
01
10
11
, b
3
0
Read / Write protection bit setting
Password Control bits
Password system area
b
2
00
01
10
11
xx
, b
1
Sector access when password
Read
Read
Read
Read
Read
Table
7 8
Doc ID 15170 Rev 9
4
to b
presented
10.
The sector is not protected by a Password
The sector is protected by the Password 1
The sector is protected by the Password 2
The sector is protected by the Password 3
1
of the Sector security status byte are affected by the
No Write
Write
Write
Write
Write
Password 1
Password 2
Password 3
15 16
Password
3
, b
4
) are the Password Control bits. The
Sector access when password not
No Read
No Read
0
Read
Read
Read
, is set to ‘1’ automatically.
23
presented
System memory area
24
Table
No Write
No Write
No Write
9.
Write
Write
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