AM29PDL128G70 SPANSION [SPANSION], AM29PDL128G70 Datasheet - Page 39

• Manufacturer Part Number: AM29PDL128G70
• Description: 128 Megabit (8 M x 16-Bit/4 M x 32-Bit) CMOS 3.0 Volt-only, Simultaneous Read/ Write Flash Memory with VersatileIO Control
• Manufacturer: SPANSION [SPANSION]

a x32 bit data bus, 2 Password Program commands
are required. The user must enter the unlock cycle,
password program command (38h) and the program
address/data for each portion of the password when
programming. There is no special addressing order re-
quired for programming the password. Also, when the
password is undergoing programming, Simultaneous
Operation is disabled. Read operations to any memory
location will return the programming status. Once pro-
g ra m m in g is co m pl et e, t he use r m us t issu e a
Read/Reset command to return the device to normal
operation. Once the Password is written and verified,
the Password Mode Locking Bit must be set in order to
prevent verification. The Password Program Com-
mand is only capable of programming “0”s. Program-
ming a “1” after a cell is programmed as a “0” results in
a time-out by the Embedded Program Algorithm™
with the cell remaining as a “0”. The password is all F’s
when shipped from the factory. All 64-bit password
combinations are valid as a password.
Password Programming is permitted if the SecSi sec-
tor is enabled.
Password Verify Command
The Password Verify Command is used to verify the
Password. The Password is verifiable only when the
Password Mode Locking Bit is not programmed. If the
Password Mode Locking Bit is programmed and the
user attempts to verify the Password, the device will
always drive all F’s onto the DQ data bus.
The Password Verify command is permitted if the
SecSi sector is enabled. Also, the device will not oper-
ate in Simultaneous Operation when the Password
Verify command is executed. Only the password is re-
turned regardless of the bank address. The lower two
address bits (A0:A-1) are valid during the Password
Verify. Writing the Read/Reset command returns the
device back to normal operation.
Password Protection Mode Locking Bit
Program Command
The Password Protection Mode Locking Bit Program
Command programs the Password Protection Mode
Locking Bit, which prevents further verifies or updates
to the Password. Once programmed, the Password
Protection Mode Locking Bit cannot be erased! If the
Password Protection Mode Locking Bit is verified as
program without margin, the Password Protection
Mode Locking Bit Program command can be executed
to improve the program margin. Once the Password
Protection Mode Locking Bit is programmed, the Per-
sistent 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.
38
P R E L I M I N A R Y
Am29PDL128G
The Password Protection Mode Locking Bit Program
command is permitted if the SecSi sector is enabled.
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 Pass-
word Mode Locking Bit from ever being programmed.
If the Persistent Sector Protection Mode Locking Bit is
verified as programmed without margin, the Persistent
Sector Protection Mode Locking Bit Program Com-
mand should be reissued to improve 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.
The Persistent Sector Protection Mode Locking Bit
Program command is permitted if the SecSi sector is
enabled.
SecSi Sector Protection Bit Program
Command
The SecSi Sector Protection Bit Program Command
programs the SecSi Sector Protection Bit, which pre-
vents the SecSi sector memory from being cleared. If
the SecSi Sector Protection Bit is verified as pro-
grammed without margin, the SecSi Sector Protection
Bit Program Command should be reissued to improve
program margin. Exiting the V
Protection Bit Program Command is accomplished by
writing the Read/Reset command.
The SecSi Sector Protection Bit Program command is
permitted if the SecSi sector is enabled.
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 exe-
cuted. There is no PPB Lock Bit Clear command.
Once the PPB Lock Bit is set, it cannot be cleared un-
less the device is taken through a power-on clear or
the Password Unlock command 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. In the Persistent Sector Protec-
tion mode, exiting the PPB Lock Bit Set command is
accomplished by writing the Read/Reset command.
The PPB Lock Bit Set command is permitted if the
SecSi sector is enabled.
CC
-level SecSi Sector
July 29, 2002