s29as008j Meet Spansion Inc., s29as008j Datasheet - Page 21

• Manufacturer Part Number: s29as008j
• Description: 8 Megabit 1 M X 8-bit/512 K X 16-bit Cmos 1.8 Volt-only Boot Sector Flash Memory
• Manufacturer: Meet Spansion Inc.

7.12
7.13
June 6, 2008 S29AS008J_00_03
Temporary Sector Unprotect
Write Protect (WP#)
This feature allows temporary unprotection of previously protected sectors to change data in-system. The
Sector Unprotect mode is activated by setting the RESET# pin to V
sectors can be programmed or erased by selecting the sector addresses. Once V
RESET# pin, all the previously protected sectors are protected again.
Figure 18.10 on page 49
protected by the WP# input will remain protected during the Temporary Sector Unprotect mode.
Notes
1. All protected sectors unprotected.
2. All previously protected sectors are protected once again.
The Write Protect function provides a hardware method of protecting certain boot sectors without using VID.
This function is one of two provided by the WP# pin.
If the system asserts V
outermost 8-Kbyte boot sectors independently of whether those sectors were protected or unprotected using
the method described in
Kbyte boot sectors are the two sectors containing the lowest addresses in a bottom-boot-configured device,
or the two sectors containing the highest addresses in a top-boot-configured device.
If the system asserts V
sectors were last set to be protected or unprotected. That is, sector protection or unprotection for these two
sectors depends on whether they were last protected or unprotected using the method described in
Section
Note that the WP# pin must not be left floating or unconnected; inconsistent behavior of the device may
result.
D a t a
7.11.
S h e e t
IL
IH
Section 7.11, Sector Protection/Unprotection on page
on the WP# pin, the device disables program and erase functions in the two
on the WP# pin, the device reverts to whether the two outermost 8-KByte boot
shows the timing diagrams, for this feature. If the WP# pin is at V
( A d v a n c e
Figure 7.2 Temporary Sector Unprotect Operation
S29AS008J
I n f o r m a t i o n )
Unprotect Completed
Program Operations
Temporary Sector
Perform Erase or
RESET# = V
RESET# = V
(Note 1)
(Note 2)
START
ID
IH
ID
. During this mode, formerly protected
Figure 7.2
19. The two outermost 8-
shows the algorithm, and
ID
is removed from the
IL
, the sectors
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