AT45DB041D_08 Datasheet, PDF (14/53 Pages) ATMEL Corporation – 4-megabit 2.5-volt or 2.7-volt DataFlash

9.1 Sector Protection Register
The nonvolatile Sector Protection Register specifies which sectors are to be protected or unpro-
tected with either the software or hardware controlled protection methods. The Sector Protection
Register contains 8 bytes of data, of which byte locations 0 through 7 contain values that specify
whether sectors 0 through 7 will be protected or unprotected. The Sector Protection Register is
user modifiable and must first be erased before it can be reprogrammed. Table 9-3 illustrates the
format of the Sector Protection Register.:
Table 9-2. Sector Protection Register
Sector Number
Protected
Unprotected
0 (0a, 0b)
See Table 9-3
1 to 7
FFH
00H
Table 9-3. Sector 0 (0a, 0b)
0a
0b
(Page 0-7)
(Page 8-255)
Bit 7, 6
Bit 5, 4
Bit 3, 2 Bit 1, 0
Sectors 0a, 0b Unprotected
00
00
xx
xx
Protect Sector 0a
11
00
xx
xx
Protect Sector 0b (Page 8-255)
00
11
xx
xx
Protect Sectors 0a (Page 0-7), 0b
(Page 8-255)⁽¹⁾
11
11
xx
xx
Note: 1. The default value for bytes 0 through 7 when shipped from Atmel^® is 00H.
x = don’t care.
Data
Value
0xH
CxH
3xH
FxH
14 AT45DB041D
3595L–DFLASH–4/08