
18
Am29LV320D
July 30, 2002
The alternate method intended only for programming
equipment, and requires V
ID on address pin A9 and
OE#. This method is compatible with programmer rou-
tines written for earlier 3.0 volt-only AMD flash de-
vices. For detailed information, contact an AMD
representative.
The device is shipped with all sectors unprotected.
AMD offers the option of programming and protecting
sectors at its factory prior to shipping the device
through AMD’s ExpressFlash Service. Contact an
AMD representative for details.
It is possible to determine whether a sector is pro-
tion for details.
Write Protect (WP#)
The Write Protect function provides a hardware
method of protecting certain boot sectors without
using V
ID. This function is one of two provided by the
WP#/ACC pin.
If the system asserts V
IL on the WP#/ACC pin, the de-
vice disables program and erase functions in the two
“outermost” 8 Kbyte boot sectors independently of
whether those sectors were protected or unprotected
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
IH on the WP#/ACC pin, the de-
vice reverts to whether the two outermost 8K Byte
boot sectors were last set to be protected or unpro-
tected. That is, sector protection or unprotection for
these two sectors depends on whether they were last
protected or unprotected using the method described
Note that the WP#/ACC pin must not be left floating or
unconnected; inconsistent behavior of the device may
result.
Temporary Sector Unprotect
This feature allows temporary unprotection of previ-
ously protected sectors to change data in-system. The
Sector Unprotect mode is activated by setting the RE-
SET# pin to V
ID (11.5 V – 12.5 V). During this mode,
formerly protected sectors can be programmed or
erased by selecting the sector addresses. Once V
ID is
removed from the RESET# pin, all the previously pro-
tected sectors are protected again.
Figure 1 shows the
algorithm, and
Figure 23 shows the timing diagrams,
for this feature.
Figure 1.
Temporary Sector Unprotect Operation
START
Perform Erase or
Program Operations
RESET# = V
IH
Temporary Sector
Unprotect Completed
(Note 2)
RESET# = V
ID
(Note 1)
Notes:
1. All protected sectors unprotected (If WP#/ACC = V
IL,
outermost boot sectors will remain protected).
2. All previously protected sectors are protected once
again.