S71PL129JC0 Datasheet, PDF (39/149 Pages) SPANSION – Stacked Multi-Chip Product (MCP) Flash Memory

Advance Information
Temporary Sector Unprotect
This feature allows temporary unprotection of previously protected sectors to
change data in-system. The Sector Unprotect mode is activated by setting the
RESET# pin to V_ID. During this mode, formerly protected sectors can be pro-
grammed or erased by selecting the sector addresses. Once V_ID is removed from
the RESET# pin, all the previously protected sectors are protected again.
Figure 2 shows the algorithm, and Figure 21 shows the timing diagrams, for this
feature. While PPB lock is set, the device cannot enter the Temporary Sector Un-
protection Mode.
START
RESET# = V_ID
(Note 1)
Perform Erase or
Program Operations
RESET# = V_IH
Temporary Sector
Unprotect Completed
(Note 2)
Notes:
1. All protected sectors are unprotected (If WP#/ACC = V_IL, upper two and lower
two sectors remain protected).
2. All previously protected sectors are protected once again
Figure 2. Temporary Sector Unprotect Operation
Secured Silicon Sector Flash Memory Region
The Secured Silicon Sector feature provides a Flash memory region that enables
permanent part identification through an Electronic Serial Number (ESN) The
128-word Secured Silicon sector is divided into 64 factory-lockable words that
can be programmed and locked by the customer. The Secured Silicon sector is
located at addresses 000000h-00007Fh in both Persistent Protection mode and
Password Protection mode. Indicator bits DQ6 and DQ7 are used to indicate the
factory-locked and customer locked status of the part.
The system accesses the Secured Silicon Sector through a command sequence
(see “Enter Secured Silicon Sector/Exit Secured Silicon Sector Command Se-
quence” on page 46). After the system has written the Enter Secured Silicon
Sector command sequence, it may read the Secured Silicon Sector by using the
addresses normally occupied by the boot sectors. This mode of operation contin-
ues until the system issues the Exit Secured Silicon Sector command sequence,
or until power is removed from the device. On power-up, or following a hardware
reset, the device reverts to sending commands to the normal address space. Note
that the ACC function and unlock bypass modes are not available when the Se-
cured Silicon Sector is enabled.
June 4, 2004 S29PL129J_MCP_00_A0
S29PL129J for MCP
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