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August 12, 2004 S29PL127J_064J_032J_MCP_00_A3
S29PL127J/S29PL064J/S29PL032J for MCP
53
A d v a n c e I n f o r m a t i o n
Sector Protection
The PL127J, PL064J, and PL032J features several levels of sector protection,
which can disable both the program and erase operations in certain sectors or
sector groups.
Sector Protection Schemes
Password Sector Protection
A highly sophisticated protection method that requires a password before
changes to certain sectors or sector groups are permitted
WP# Hardware Protection
A write protect pin that can prevent program or erase operations in sectors SA1-
133, SA1-134, SA2-0 and SA2-1.
The WP# Hardware Protection feature is always available, independent of the
software managed protection method chosen.
Selecting a Sector Protection Mode
All parts default to operate in the Persistent Sector Protection mode. The cus-
tomer must then choose if the Persistent or Password Protection method is most
desirable. There are two one-time programmable non-volatile bits that define
which sector protection method will be used. If the Persistent Sector Protection
method is desired, programming the Persistent Sector Protection Mode Locking
Bit permanently sets the device to the Persistent Sector Protection mode. If the
Password Sector Protection method is desired, programming the Password Mode
Locking Bit permanently sets the device to the Password Sector Protection mode.
It is not possible to switch between the two protection modes once a locking bit
has been set. One of the two modes must be selected when the device is first
programmed. This prevents a program or virus from later setting the Password
Mode Locking Bit, which would cause an unexpected shift from the default Per-
sistent Sector Protection Mode into the Password Protection Mode.
The device is shipped with all sectors unprotected. Optional Spansion program-
ming services enable programming and protecting sectors at the factory prior to
shipping the device. Contact your local sales office for details.
Table 12. Sector Protection Schemes
DYB
PPB
PPB Lock
Sector State
0
0
0
Unprotected—PPB and DYB are changeable
0
0
1
Unprotected—PPB not changeable, DYB is changeable
0
1
0
Protected—PPB and DYB are changeable
1
0
0
1
1
0
0
1
1
Protected—PPB not changeable, DYB is changeable
1
0
1
1
1
1