S71PL064JB0BFW0B0 Spansion Inc., S71PL064JB0BFW0B0 Datasheet - Page 70

• Manufacturer Part Number: S71PL064JB0BFW0B0
• Manufacturer: Spansion Inc.

Specifications of S71PL064JB0BFW0B0

• Operating Supply Voltage (max): 3.1V
• Operating Temperature (max): 85C
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

71
Password Program Command
Password Verify Command
Password Protection Mode Locking Bit Program Command
operation using the DQ7 or DQ6 status bits, just as in the standard Word Program
operation. Refer to the Write Operation Status section for more information.
In the erase-suspend-read mode, the system can also issue the autoselect com-
mand sequence. The device allows reading autoselect codes even at addresses
within erasing sectors, since the codes are not stored in the memory array. When
the device exits the autoselect mode, the device reverts to the Erase Suspend
mode, and is ready for another valid operation. Refer to the SecSiTM Sector Ad-
dresses and the Autoselect Command Sequence sections for details.
To resume the sector erase operation, the system must write the Erase Resume
command (address bits are don’t care). The bank address of the erase-sus-
pended bank is required when writing this command. Further writes of the
Resume command are ignored. Another Erase Suspend command can be written
after the chip has resumed erasing.
The Password Program Command permits programming the password that is
used as part of the hardware protection scheme. The actual password is 64-bits
long. Four Password Program commands are required to program the password.
The system must enter the unlock cycle, password program command (38h) and
the program address/data for each portion of the password when programming.
There are no provisions for entering the 2-cycle unlock cycle, the password pro-
gram command, and all the password data. There is no special addressing order
required for programming the password. Also, when the password is undergoing
programming, Simultaneous Operation is disabled. Read operations to any mem-
ory location will return the programming status. Once programming is complete,
the user must issue a Read/Reset command to return the device to normal oper-
ation. Once the Password is written and verified, the Password Mode Locking Bit
must be set in order to prevent verification. The Password Program Command is
only capable of programming “0”s. Programming 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 ones when shipped from the factory. All
64-bit password combinations are valid as a password.
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 operate in Simultaneous Operation when the Password Verify
command is executed. Only the password is returned regardless of the bank ad-
dress. The lower two address bits (A1-A0) are valid during the Password Verify.
Writing the Read/Reset command returns the device back to normal operation.
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 pro-
gram without margin, the Password Protection Mode Locking Bit Program
command can be executed to improve the program margin. Once the Password
S29PL127J/S29PL064J/S29PL032J for MCP
P r e l i m i n a r y
S29PL127_064_032J_00_A1 May 21, 2004