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 64 bytes of data, of which byte locations 0 through 63 contain values that
specify whether sectors 0 through 63 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 63
FFH
See Table 9-3
Unprotected
00H
Table 9-3.
Sector 0 (0a, 0b)
0a
0b
(Pages 0-7)
(Pages 8-127)
Data
Value
Bit 7, 6
00
Bit 5, 4
00
Bit 3, 2
xx
Bit 1, 0
xx
Sectors 0a, 0b Unprotected
Protect Sector 0a (Pages 0-7)
Protect Sector 0b (Pages 8-127)
0xH
CxH
3xH
11
00
xx
xx
00
11
xx
xx
Protect Sectors 0a (Pages 0-7), 0b
(Pages 8-127)(1)
11
11
xx
xx
FxH
Note:
1. The default value for bytes 0 through 63 when shipped from Atmel is 00H.
x = don’t care.
14
AT45DB321D [Preliminary]
3597H–DFLASH–02/07
ATMEL [ ATMEL ]
