compatible with programmer routines written
for earlier 3.0 volt-only AMD flash devices. For
detailed information, contact an AMD represen-
tative.
The device is shipped with all sectors unpro-
tected. AMD offers the option of programming
and protecting sectors at its factory prior to
shipping the device through AMD’s Express-
Flash™ Service. Contact an AMD representative
for details.
It is possible to determine whether a sector is
protected or unprotected. See
“Autoselect
Mode” on page 16
for details.
23, on page 46
shows the timing diagrams, for
this feature.
START
RESET# = V
ID
(Note 1)
Perform Erase or
Program
Write Protect (WP#)
The Write Protect function provides a hardware
method of protecting certain boot sectors with-
out using V
ID
. This function is one of two pro-
vided by the WP#/ACC pin.
If the system asserts V
IL
on the WP#/ACC pin,
the device disables program and erase func-
tions in the two “outermost” 8 Kbyte boot sec-
tors independently of whether those sectors
w er e p r ote cte d or un pro tec ted usi ng the
method described in
“Sector/Sector Block Pro-
tection and Unprotection” on page 17.
outermost 8 Kbyte boot sectors are the two
sectors containing the lowest addresses in a
bottom-boot-configured device, or the two sec-
tors containing the highest addresses in a
top-boot-configured device.
If the system asserts V
IH
on the WP#/ACC pin,
the device reverts to whether the two outer-
most 8K Byte boot sectors were last set to be
protected or unprotected. That is, sector pro-
tection or unprotection for these two sectors
depends on whether they were last protected
or unprotected using the method described in
“Sector/Sector Block Protection and Unprotec-
tion” on page 17.
Note that the WP#/ACC pin must not be left
floating or unconnected; inconsistent behavior
of the device may result.
RESET# = V
IH
Temporary Sector
Unprotect Completed
(Note 2)
Notes:
1. All protected sectors unprotected (If WP#/ACC =
V
IL
, outermost boot sectors remain protected).
2. All previously protected sectors are protected
once again.
Figure 1.
Temporary Sector Unprotect
Operation
Temporary Sector Unprotect
This feature allows temporary unprotection of
previously protected sectors to change data
in-system. The Sector Unprotect mode is acti-
vated by setting the RESET# pin to V
ID
(11.5 V
– 12.5 V). During this mode, formerly pro-
tected sectors can be programmed or erased by
selecting the sector addresses. Once V
ID
is re-
moved from the RESET# pin, all the previously
protected sectors are protected again.
Figure 1,
on page 18
shows the algorithm, and
18
November 15, 2004
SPANSION [ SPANSION ]
