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
0 (0a, 0b)
1 to 7
FFH
00H
See Table 9-3
Unprotected
Table 9-3.
Sector 0 (0a, 0b)
0a
(Page 0-7)
Bit 7, 6
00
0b
(Page 8-255)
Data
Value
Bit 5, 4
00
Bit 3, 2
xx
Bit 1, 0
xx
Sectors 0a, 0b Unprotected
Protect Sector 0a
0xH
CxH
3xH
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
FxH
Note:
1. The default value for bytes 0 through 7 when shipped from Atmel® is 00H.
x = don’t care.
14
AT45DB041D
3595L–DFLASH–4/08
ATMEL [ ATMEL ]
