am49pdl127ah Meet Spansion Inc., am49pdl127ah Datasheet - Page 39

• Manufacturer Part Number: am49pdl127ah
• Description: Stacked Multi-chip Package Mcp Flash Memory And Psram, 128 Megabit 8m ? 16-bit Cmos 3.0 Volt-only, Simultaneous Operation Flash Memory And 16 Mbit 1m ? 16-bit Cmos Pseudo Static Ram
• Manufacturer: Meet Spansion Inc.

Note that the WP#/ACC pin must not be left floating or
unconnected; inconsistent behavior of the device may
result.
Persistent Protection Bit Lock
The Persistent Protection Bit (PPB) Lock is a volatile
bit that reflects the state of the Password Mode Lock-
ing 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. Suc-
cessful execution of the Password Unlock command
clears the PPB Lock Bit, allowing for sector PPBs
modifications. Asserting 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.
December 18, 2003
A D V A N C E
Am49PDL127AH/Am49PDL129AH
I N F O R M A T I O N
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 com-
mand. Once set the only means for clearing the PPB
Lock Bit is by issuing a hardware or power-up reset.
The Password Unlock command is ignored in Persis-
tent Protection Mode.
High Voltage Sector Protection
Sector protection and unprotection may also be imple-
mented using programming equipment. The proce-
dure requires high voltage (V
RESET# pin. Refer to Figure 1 for details on this pro-
cedure. Note that for sector unprotect, all unprotected
sectors must first be protected prior to the first sector
write cycle.
ID
) to be placed on the
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