AM29LV641G AMD [Advanced Micro Devices], AM29LV641G Datasheet - Page 20

• Manufacturer Part Number: AM29LV641G
• 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 de-
scribed in “Sector Group Protection and Unprotection”.
Note that if WP# is at V
standby mode, the maximum input load current is in-
creased. 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 V
this mode, formerly protected sector groups can be
programmed or erased by selecting the sector group
addresses. Once V
pin, all the previously protected sector groups are
protected again. Figure 1 shows the algorithm, and
Figure 22 shows the timing diagrams, for this feature.
21
ID
.
ID
is removed from the RESET#
IH
IL
IL
on the WP# pin, the device
on the WP# pin, the device
when the device is in the
ID
(8.5 V – 12.5 V). During
A D V A N C E
Am29LV641G
I N F O R M A T I O N
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
ID
IH
June 14, 2005
IL
,