AM29LV641ML AMD [Advanced Micro Devices], AM29LV641ML Datasheet - Page 18

• Manufacturer Part Number: AM29LV641ML
• Manufacturer: AMD [Advanced Micro Devices]

Write Protect (WP#)
The Write Protect function provides a hardware
method of protecting the first or last sector without
using V
If the system asserts V
disables program and erase functions in the first or last
sector independently of whether those sectors were
protected or unprotected using the method described
in “Sector Group Protection and Unprotection”. Note
that if WP# is at V
mode, the maximum input load current is increased.
See the table in “DC Characteristics”.
If the system asserts V
reverts to whether the first or last sector was previ-
ously set to be protected or unprotected using the
method described in “Sector Group Protection and
Unprotection”.
Temporary Sector Group Unprotect
(Note: In this device, a sector group consists of four adjacent
sectors that are protected or unprotected at the same time
(see Table 4).
This feature allows temporary unprotection of previ-
ously protected sector groups to change data in-sys-
tem. The Sector Group Unprotect mode is activated by
setting the RESET# pin to
merly protected sector groups can be programmed or
erased by selecting the sector group addresses. Once
V
protected sector groups are protected again. Figure 1
shows the algorithm, and Figure 24 shows the timing
diagrams, for this feature.
16
ID
is removed from the RESET# pin, all the previously
ID
.
IL
when the device is in the standby
IL
IH
on the WP# pin, the device
on the WP# pin, the device
V
ID
. During this mode, for-
D A T A S H E E T
Am29LV641MH/L
Notes:
1. All protected sector groups unprotected (If WP# = V
2. All previously protected sector groups are protected
the first or last sector will remain protected).
once again.
Figure 1. Temporary Sector Group
Unprotect Operation
Program Operations
Completed (Note 2)
Temporary Sector
Perform Erase or
Group Unprotect
RESET# = V
RESET# = V
(Note 1)
START
December 21, 2005
ID
IH
IL
,