D A T A S H E E T
When the Embedded Erase algorithm is complete, the
within erase-suspended sectors produces status infor-
mation on DQ7–DQ0. The system can use DQ7, or
DQ6 and DQ2 together, to determine if a sector is
actively erasing or is erase-suspended. Refer to the
Write Operation Status section for information on these
status bits.
bank returns to reading array data and addresses are
no longer latched. Note that while the Embedded Erase
operation is in progress, the system can read data from
the non-erasing bank. The system can determine the
status of the erase operation by reading DQ7 or DQ6/
DQ2 in the erasing bank. Refer to the Write Operation
Status section for information on these status bits.
After an erase-suspended program operation is com-
plete, the bank returns to the erase-suspend-read
mode. The system can determine the status of the
program operation using the DQ7 or DQ6 status bits,
just as in the standard program operation. Refer to the
Write Operation Status section for more information.
Once the sector erase operation has begun, only the
Erase Suspend command is valid. All other commands
are ignored. However, note that a hardware reset
immediately terminates the erase operation. If that
occurs, the sector erase command sequence should
be reinitiated once that bank has returned to reading
array data, to ensure data integrity.
In the erase-suspend-read mode, the system can also
issue the autoselect command sequence. Refer to the
Autoselect Functions and Autoselect Command
Sequence sections for details.
The host system may also initiate the sector erase
command sequence while the device is in the unlock
bypass mode. The command sequence is four cycles
cycles in length instead of six cycles.
To resume the sector erase operation, the system must
write the Erase Resume command. The bank address
of the erase-suspended 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.
Figure 2 illustrates the algorithm for the erase opera-
tion. Refer to the Erase/Program Operations table in
the AC Characteristics section for parameters, and
Figure 14 section for timing diagrams.
Erase Suspend/Erase Resume
Commands
START
The Erase Suspend command, B0h, allows the sys-
tem to interrupt a sector erase operation and then read
data from, program data to, any sector not selected for
erasure. The system may also lock or unlock any sec-
tor while the erase operation is suspended. The sys-
tem must not write the sector lock/unlock
command to sectors selected for erasure. The
bank address is required when writing this command.
This command is valid only during the sector erase op-
eration, including the minimum 50 µs time-out period
during the sector erase command sequence. The
Erase Suspend command is ignored if written during
the chip erase operation or Embedded Program
algorithm.
Write Erase
Command Sequence
Data Poll
from System
Embedded
Erase
algorithm
in progress
No
Data = FFh?
When the Erase Suspend command is written during
the sector erase operation, the device requires a
maximum of 20 µs to suspend the erase operation.
However, when the Erase Suspend command is written
during the sector erase time-out, the device immedi-
ately terminates the time-out period and suspends the
erase operation.
Yes
Erasure Completed
Notes:
After the erase operation has been suspended, the
bank enters the erase-suspend-read mode. The
system can read data from or program data to any
sector not selected for erasure. (The device “erase sus-
pends” all sectors selected for erasure.) The system
may also lock or unlock any sector while in the
erase-suspend-read mode. Reading at any address
1. See Table 10 for erase command sequence.
2. See the section on DQ3 for information on the sector
erase timer.
Figure 2. Erase Operation
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Am29BDS643G
25692A2 May 8, 2006
SPANSION [ SPANSION ]
