S71PL129JC0 Datasheet, PDF (52/149 Pages) SPANSION – Stacked Multi-Chip Product (MCP) Flash Memory

Advance Information
command can be executed to improve the program margin. Once the Password
Protection Mode Locking Bit is programmed, the Persistent Sector Protection
Locking Bit program circuitry is disabled, thereby forcing the device to remain in
the Password Protection mode. Exiting the Mode Locking Bit Program command
is accomplished by writing the Read/Reset command.
Persistent Sector Protection Mode Locking Bit Program Command
The Persistent Sector Protection Mode Locking Bit Program Command programs
the Persistent Sector Protection Mode Locking Bit, which prevents the Password
Mode Locking Bit from ever being programmed. If the Persistent Sector Protec-
tion Mode Locking Bit is verified as programmed without margin, the Persistent
Sector Protection Mode Locking Bit Program Command should be reissued to im-
prove program margin. By disabling the program circuitry of the Password Mode
Locking Bit, the device is forced to remain in the Persistent Sector Protection
mode of operation, once this bit is set. Exiting the Persistent Protection Mode
Locking Bit Program command is accomplished by writing the Read/Reset
command.
Secured Silicon Sector Protection Bit Program Command
The Secured Silicon Sector Protection Bit Program Command programs the Se-
cured Silicon Sector Protection Bit, which prevents the Secured Silicon sector
memory from being cleared. If the Secured Silicon Sector Protection Bit is verified
as programmed without margin, the Secured Silicon Sector Protection Bit Pro-
gram Command should be reissued to improve program margin. Exiting the V_CC-
level Secured Silicon Sector Protection Bit Program Command is accomplished by
writing the Read/Reset command.
PPB Lock Bit Set Command
The PPB Lock Bit Set command is used to set the PPB Lock bit if it is cleared either
at reset or if the Password Unlock command was successfully executed. There is
no PPB Lock Bit Clear command. Once the PPB Lock Bit is set, it cannot be cleared
unless the device is taken through a power-on clear or the Password Unlock com-
mand is executed. Upon setting the PPB Lock Bit, the PPBs are latched into the
DYBs. If the Password Mode Locking Bit is set, the PPB Lock Bit status is reflected
as set, even after a power-on reset cycle. Exiting the PPB Lock Bit Set command
is accomplished by writing the Read/Reset command (only in the Persistent Pro-
tection Mode).
DYB Write Command
The DYB Write command is used to set or clear a DYB for a given sector. The high
order address bits (Amax–A12) are issued at the same time as the code 01h or
00h on DQ7-DQ0. All other DQ data bus pins are ignored during the data write
cycle. The DYBs are modifiable at any time, regardless of the state of the PPB or
PPB Lock Bit. The DYBs are cleared at power-up or hardware reset.Exiting the
DYB Write command is accomplished by writing the Read/Reset command.
Password Unlock Command
The Password Unlock command is used to clear the PPB Lock Bit so that the PPBs
can be unlocked for modification, thereby allowing the PPBs to become accessible
for modification. The exact password must be entered in order for the unlocking
function to occur. This command cannot be issued any faster than 2 µs at a time
to prevent a hacker from running through all 64-bit combinations in an attempt
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S29PL129J for MCP
S29PL129J_MCP_00_A0 June 4, 2004