Rainbow Electronics AT45DQ321 - Manual (Page 23)

23 AT45DQ321 [ADVANCE DATASHEET]
DS-45DQ321-031–DFLASH–12/2012
Figure 7-3. WP Pin and Protection Status
Table 7-3. WP Pin and Protection Status
7.3 Sector Protection Register
The nonvolatile Sector Protection Register specifies which sectors are to be protected or unprotected 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 be erased before it can be reprogrammed.
Table 7-4
illustrates the format of the Sector Protection Register.
Table 7-4. Sector Protection Register
Note: 1. The default values for bytes 0 through 63 are 00h when shipped from Adesto.
Table 7-5. Sector 0 (0a, 0b) Sector Protection Register Byte Value
Note: 1. x = Don’t care
Time
Period WP Pin Enable Sector Protection Command
Disable Sector
Protection Command
Sector
Protection
Status
Sector
Protection
Register
1 High
Command Not Issued Previously X Disabled Read/Write
— Issue Command Disabled Read/Write
Issue Command — Enabled Read/Write
2 Low X X Enabled Read
3 High
Command Issued During Period 1 or 2 Not Issued Yet Enabled Read/Write
— Issue Command Disabled Read/Write
Issue Command — Enabled Read/Write
WP
1 2 3
Sector Number 0 (0a, 0b) 1 to 63
Protected
See Table 7-5
FFh
Unprotected 00h
Bit 7:6 Bit 5:4 Bit 3:2 Bit 1:0
Data
Value
Sector 0a
(Page 0-7)
Sector 0b
(Page 8-127) N/A N/A
Sectors 0a and 0b Unprotected 00 00 XX XX 0xh
Protect Sector 0a 11 00 XX XX Cxh
Protect Sector 0b 00 11 XX XX 3xh
Protect Sectors 0a and 0b 11 11 XX XX Fxh