Instruction Manual

14
3597J–DFLASH–4/08
AT45DB321D
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.:
Note: 1. The default value for bytes 0 through 63 when shipped from Atmel is 00H.
x = don’t care.
Table 9-2. Sector Protection Register
Sector Number 0 (0a, 0b) 1 to 63
Protected
See Table 9-3
FFH
Unprotected 00H
Table 9-3. Sector 0 (0a, 0b)
0a 0b
Bit 3, 2
Data
Value
(Pages 0-7) (Pages 8-127)
Bit 7, 6 Bit 5, 4 Bit 1, 0
Sectors 0a, 0b Unprotected 00 00 xx xx 0xH
Protect Sector 0a (Pages 0-7) 11 00 xx xx CxH
Protect Sector 0b (Pages 8-127) 00 11 xx xx 3xH
Protect Sectors 0a (Pages 0-7), 0b
(Pages 8-127)
(1)
11 11 xx xx FxH