at25dq321a ATMEL Corporation, at25dq321a Datasheet - Page 37

• Manufacturer Part Number: at25dq321a
• Description: 32-megabit 2.7-volt Minimum Spi Serial Flash Memory With Dual-i/o And Quad-i/o Support
• Manufacturer: ATMEL Corporation

8718A–DFLASH–04/10
Table 11-2.
Notes:
11.1.1 SPRL Bit
Bit
7
6
5
4
3
2
1
0
(2)
1. Only bits 4 and 3 of Status Register Byte 2 will be modified when using the Write Status Register Byte 2 command.
2. R/W = Readable and writeable
The SPRL bit is used to control whether the Sector Protection Registers can be modified or not. When the SPRL
bit is in the logical “1” state, all Sector Protection Registers are locked and cannot be modified with the Protect
Sector and Unprotect Sector commands (the device will ignore these commands). In addition, the Global Protect
and Global Unprotect features cannot be performed. Any sectors that are presently protected will remain protected,
and any sectors that are presently unprotected will remain unprotected.
When the SPRL bit is in the logical “0” state, all Sector Protection Registers are unlocked and can be modified (the
Protect Sector and Unprotect Sector commands, as well as the Global Protect and Global Unprotect features, will
be processed as normal). The SPRL bit defaults to the logical “0” state after device power-up. The Reset command
has no effect on the SPRL bit.
The SPRL bit can be modified freely whenever the WP pin is deasserted. However, if the WP pin is asserted, then
the SPRL bit may only be changed from a logical “0” (Sector Protection Registers are unlocked) to a logical “1”
(Sector Protection Registers are locked). In order to reset the SPRL bit back to a logical “0” using the Write Status
Register Byte 1 command, the WP pin will have to first be deasserted.
The SPRL bit is the only bit of Status Register Byte 1 that can be user modified via the Write Status Register Byte
1 command.
RDY/BSY
RSTE
RES
RES
RES
R = Readable only
SLE
PS
ES
Status Register Format – Byte 2
Reserved for future use
Reserved for future use
Reserved for future use
Reset Enabled
Sector Lockdown Enabled
Program Suspend Status
Erase Suspend Status
Ready/Busy Status
Name
Type
R/W
R/W
R
R
R
R
R
R
(2)
0
0
0
0
1
0
1
0
1
0
1
0
1
AT25DQ321A [Preliminary]
Reserved for future use.
Reserved for future use.
Reserved for future use.
Reset command is disabled (default).
Reset command is enabled.
Sector Lockdown and Freeze Sector Lockdown State
commands are disabled (default).
Sector Lockdown and Freeze Sector Lockdown State
commands are enabled.
No sectors are program suspended (default).
A sector is program suspended.
No sectors are erase suspended (default).
A sector is erase suspended.
Device is ready.
Device is busy with an internal operation.
Description
37