S29PL-N SPANSION [SPANSION], S29PL-N Datasheet - Page 55

• Manufacturer Part Number: S29PL-N
• Description: 256/128/128 Mb (16/8/8 M x 16-Bit) CMOS, 3.0 Volt-only Simultaneous Read/Write, Page-Mode Flash Memory
• Manufacturer: SPANSION [SPANSION]

8.6
8.7
November 23, 2005 S29PL-N_00_A4
Advanced Sector Protection Software Examples
Hardware Data Protection Methods
8.7.1 WP# Method
8.7.2 Low V
Table 8.2
tus of the sector. In summary, if the PPB Lock Bit is locked (set to 0), no changes to the PPBs are
allowed. The PPB Lock Bit can only be unlocked (reset to 1) through a hardware reset or power
cycle. See also
The device offers data protection at the sector level via hardware control:
There are additional methods by which intended or accidental erasure of any sectors can be pre-
vented via hardware means. The following subsections describes these methods:
The Write Protect feature provides a hardware method of protecting the four outermost sectors.
This function is provided by the WP#/ACC pin and overrides the previously discussed Sector Pro-
tection/Unprotection method.
If the system asserts V
in the outermost boot sectors. The outermost boot sectors are the sectors containing both the
lower and upper set of sectors in a dual-boot-configured device.
If the system asserts V
were last set to be protected or unprotected. That is, sector protection or unprotection for these
sectors depends on whether they were last protected or unprotected.
Note that the WP#/ACC pin must not be left floating or unconnected as inconsistent behavior of
the device may result.
The WP#/ACC pin must be held stable during a command sequence execution
When V
V
The command register and all internal program/erase circuits are disabled, and the device resets
to reading array data. Subsequent writes are ignored until V
must provide the proper signals to the control inputs to prevent unintentional writes when V
greater than V
CC
When WP#/ACC is at V
power-up and power-down.
Unique Device PPB Lock Bit
0 = locked, 1 = unlocked
CC
CC
Any Sector
Any Sector
Any Sector
Any Sector
Any Sector
Any Sector
Any Sector
Any Sector
contains all possible combinations of the DYB, PPB, and PPB Lock Bit relating to the sta-
is less than V
Write Inhibit
LKO
Figure 8.1
.
P r e l i m i n a r y
IL
LKO
IH
S29PL-N MirrorBit™ Flash Family
on the WP#/ACC pin, the device disables program and erase functions
for an overview of the Advanced Sector Protection feature.
on the WP#/ACC pin, the device reverts to whether the boot sectors
, the device does not accept any write cycles. This protects data during
IL
0
0
0
0
1
1
1
1
Table 8.2 Sector Protection Schemes
, the four outermost sectors are locked (device specific).
1 = unprotected
0 = protected
Sector PPB
0
0
1
1
0
0
1
1
1 = unprotected
0 = protected
Sector DYB
x
x
1
0
x
x
0
1
CC
is greater than V
Sector Protection Status
Protected through DYB
Protected through DYB
Protected through PPB
Protected through PPB
Protected through PPB
Protected through PPB
Unprotected
Unprotected
LKO
. The system
CC
53
is