136
S29GLxxxN MirrorBit
TM
Flash Family
S29GLxxxN_MCP_A1 December 15, 2004
A d v a n c e I n f o r m a t i o n
gram 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. Refer to the “Autoselect Mode” section and
“Autoselect
Command Sequence” section on page 127
sections for details.
To resume the sector erase operation, the system must write the Erase Resume
command. The address of the erase-suspended sector 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. It is
important to allow an interval of at least 5 ms between Erase Resume and Erase
Suspend.
Lock Register Command Set Definitions
The Lock Register Command Set permits the user to one-time program the Se-
cured Silicon Sector Protection Bit, Persistent Protection Mode Lock Bit, and
Password Protection Mode Lock Bit. The Lock Register bits are all readable after
an initial access delay.
The
Lock Register Command Set Entry
command sequence must be issued
prior to any of the following commands listed, to enable proper command
execution.
Note that issuing the
Lock Register Command Set Entry
command
disables
reads and writes for the flash memory
.
Lock Register Program Command
Lock Register Read Command
The
Lock Register Command Set Exit
command must be issued after the ex-
ecution of the commands to reset the device to read mode. Otherwise the device
will hang. If this happens, the flash device must be reset. Please refer to RESET#
for more information. It is important to note that the device will be in either Per-
sistent Protection mode or Password Protection mode depending on the mode
selected prior to the device hang.
For either the Secured Silicon Sector to be locked, or the device to be perma-
nently set to the Persistent Protection Mode or the Password Protection Mode, the
associated Lock Register bits must be programmed.
Note that the Persistent
Protection Mode Lock Bit and Password Protection Mode Lock Bit can
never be programmed together at the same time. If so, the Lock Register
Program operation will abort
.
The Lock Register Command Set Exit command must be initiated to re-
enable reads and writes to the main memory.
Password Protection Command Set Definitions
The Password Protection Command Set permits the user to program the 64-bit
password, verify the programming of the 64-bit password, and then later unlock
the device by issuing the valid 64-bit password.
The
Password Protection Command Set Entry
command sequence must be
issued prior to any of the commands listed following to enable proper command
execution.
Note that issuing the
Password Protection Command Set Entry
command
disabled reads and writes the main memory.