S29PL032J SPANSION [SPANSION], S29PL032J Datasheet - Page 53

• Manufacturer Part Number: S29PL032J
• Description: CMOS 3.0 Volt-only, Simultaneous Read/Write Flash Memory with Enhanced VersatileIO Control
• Manufacturer: SPANSION [SPANSION]

Persistent Sector Protection
April 7, 2005 31107A62
Persistent Protection Bit (PPB)
Persistent Protection Bit Lock (PPB Lock)
Dynamic Protection Bit (DYB)
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.
It is possible to determine whether a sector is protected or unprotected. See Au-
toselect Mode for details.
The Persistent Sector Protection method replaces the 12 V controlled protection
method in previous flash devices. This new method provides three different sec-
tor protection states:
To achieve these states, three types of “bits” are used:
A single Persistent (non-volatile) Protection Bit is assigned to a maximum four
sectors (see the sector address tables for specific sector protection groupings).
All 4 Kword boot-block sectors have individual sector Persistent Protection Bits
(PPBs) for greater flexibility. Each PPB is individually modifiable through the PPB
Write Command.
The device erases all PPBs in parallel. If any PPB requires erasure, the device
must be instructed to preprogram all of the sector PPBs prior to PPB erasure. Oth-
erwise, a previously erased sector PPBs can potentially be over-erased. The flash
device does not have a built-in means of preventing sector PPBs over-erasure.
The Persistent Protection Bit Lock (PPB Lock) is a global volatile bit. When set to
“1”, the PPBs cannot be changed. When cleared (“0”), the PPBs are changeable.
There is only one PPB Lock bit per device. The PPB Lock is cleared after power-up
or hardware reset. There is no command sequence to unlock the PPB Lock.
A volatile protection bit is assigned for each sector. After power-up or hardware
reset, the contents of all DYBs is “0”. Each DYB is individually modifiable through
the DYB Write Command.
When the parts are first shipped, the PPBs are cleared, the DYBs are cleared, and
PPB Lock is defaulted to power up in the cleared state – meaning the PPBs are
changeable.
When the device is first powered on the DYBs power up cleared (sectors not pro-
tected). The Protection State for each sector is determined by the logical OR of
the PPB and the DYB related to that sector. For the sectors that have the PPBs
cleared, the DYBs control whether or not the sector is protected or unprotected.
By issuing the DYB Write command sequences, the DYBs will be set or cleared,
thus placing each sector in the protected or unprotected state. These are the
Persistently Locked—The sector is protected and cannot be changed.
Dynamically Locked—The sector is protected and can be changed by a simple
command.
Unlocked—The sector is unprotected and can be changed by a simple com-
mand.
Persistent Protection Bit
Persistent Protection Bit Lock
Persistent Sector Protection Mode Locking Bit
P R E L I M I N A R Y
S29PL127J/S29PL129J/S29PL064J/S29PL032J
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