AT45DB161E Datasheet, PDF (24/73 Pages) ATMEL Corporation – 16-Mbits DataFlash (with Extra 512-Kbits), 2.3V or 2.5V Minimum SPI Serial Flash Memory

Table 8-2. Sector Lockdown Register
Sector Number
Locked
Unlocked
0 (0a, 0b)
See Table 8-3
1 to 15
FFh
00h
Table 8-3. Sector 0 (0a and 0b) Sector Lockdown Register Byte Value
Sectors 0a and 0b Unlocked
Sector 0a Locked
Sector 0b Locked
Sectors 0a and 0b Locked
Bit 7:6
Sector 0a
(Page 0-7)
00
11
00
11
Bit 5:4
Sector 0b
(Page 8-255)
00
00
11
11
Bit 3:2
N/A
00
00
00
00
Bit 1:0
N/A
00
00
00
00
Data
Value
00h
C0h
30h
F0h
Table 8-4. Read Sector Lockdown Register Command
Command
Read Sector Lockdown Register
Byte 1
35h
Byte 2
XXh
Byte 3
XXh
Byte 4
XXh
Figure 8-2. Read Sector Lockdown Register
CS
SI
32h
XX
XX
SO
Each transition represents eight bits
XX
Data
n
Data
n+1
Data
n + 15
8.1.2
Freeze Sector Lockdown
The Sector Lockdown command can be permanently disabled, and the current sector lockdown state can be
permanently frozen so that no additional sectors can be locked down aside from those already locked down. Any
attempts to issue the Sector Lockdown command after the Sector Lockdown State has been frozen will be ignored.
To issue the Freeze Sector Lockdown command, the CS pin must be asserted and the opcode sequence of 34h, 55h,
AAh, and 40h must be clocked into the device. Any additional data clocked into the device will be ignored. When the CS
pin is deasserted, the current sector lockdown state will be permanently frozen within a time of t_LOCK. In addition, the SLE
bit in the Status Register will be permanently reset to a Logic 0 to indicate that the Sector Lockdown command is
permanently disabled.
Table 8-5. Freeze Sector Lockdown
Command
Freeze Sector Lockdown
Byte 1
34h
Byte 2
55h
Byte 3
AAh
Byte 4
40h
AT45DB161E 24
8782G–DFLASH–10/2013