S71PL129JC0 Datasheet, PDF (37/149 Pages) SPANSION – Stacked Multi-Chip Product (MCP) Flash Memory

Advance Information
Persistent Protection Bit Lock
The Persistent Protection Bit (PPB) Lock is a volatile bit that reflects the state of
the Password Mode Locking Bit after power-up reset. If the Password Mode Lock
Bit is also set after a hardware reset (RESET# asserted) or a power-up reset, the
ONLY means for clearing the PPB Lock Bit in Password Protection Mode is to issue
the Password Unlock command. Successful execution of the Password Unlock
command clears the PPB Lock Bit, allowing for sector PPBs modifications. Assert-
ing RESET#, taking the device through a power-on reset, or issuing the PPB Lock
Bit Set command sets the PPB Lock Bit to a “1” when the Password Mode Lock Bit
is not set.
If the Password Mode Locking Bit is not set, including Persistent Protection Mode,
the PPB Lock Bit is cleared after power-up or hardware reset. The PPB Lock Bit is
set by issuing the PPB Lock Bit Set command. Once set the only means for clear-
ing the PPB Lock Bit is by issuing a hardware or power-up reset. The Password
Unlock command is ignored in Persistent Protection Mode.
High Voltage Sector Protection
Sector protection and unprotection may also be implemented using programming
equipment. The procedure requires high voltage (V_ID) to be placed on the RE-
SET# pin. Refer to Figure 1 for details on this procedure. Note that for sector
unprotect, all unprotected sectors must first be protected prior to the first sector
write cycle.
June 4, 2004 S29PL129J_MCP_00_A0
S29PL129J for MCP
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