AM29LV128MH AMD [Advanced Micro Devices], AM29LV128MH Datasheet - Page 22

• Manufacturer Part Number: AM29LV128MH
• Manufacturer: AMD [Advanced Micro Devices]

Write Protect (WP#)
The Write Protect function provides a hardware
method of protecting the first or last sector group with-
out using V
vided by the WP#/ACC input.
If the system asserts V
vice disables program and erase functions in the first
or last sector group independently of whether those
sector groups were protected or unprotected using the
method described in “Sector Group Protection and
Unprotection”. Note that if WP#/ACC is at V
device is in the standby mode, the maximum input
load current is increased. See the table in “DC Char-
acteristics”.
If the system asserts V
vice reverts to whether the first or last sector was pre-
viously set to be protected or unprotected using the
method described in “Sector Group Protection and
Unprotection”. Note that WP# has an internal pullup;
when unconnected, WP# is at V
Temporary Sector Group Unprotect
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 VID. During this mode, for-
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
20
ID
is removed from the RESET# pin, all the previously
ID
. Write Protect is one of two functions pro-
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on the WP#/ACC pin, the de-
on the WP#/ACC pin, the de-
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.
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D A T A S H E E T
when the
Am29LV128MH/L
shows the algorithm, and Figure 24 shows the timing
diagrams, for this feature.
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
Temporary Sector Group
Unprotect Completed
Program Operations
Perform Erase or
RESET# = V
RESET# = V
(Note 1)
(Note 2)
START
September 9, 2003
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