AM49LV6408M Datasheet, PDF (34/63 Pages) SPANSION – Stacked Multi-chip Package (MCP) 64 Mbit (4 M x 16 bit) Flash Memory and 8 Mbit (512K x 16-Bit)

ADVANCE INFORMATION
ing edge of the final WE# pulse in the command
sequence.
When the Embedded Erase algorithm is complete, the
device returns to reading array data and addresses
are no longer latched. The system can determine the
status of the erase operation by reading DQ7, DQ6, or
DQ2 in the erasing sector. Refer to the Write Opera-
tion Status section for information on these status bits.
Once the sector erase operation has begun, only the
Erase Suspend command is valid. All other com-
mands 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 the device has returned to
reading array data, to ensure data integrity.
Figure 7 illustrates the algorithm for the erase opera-
tion. Refer to the Erase and Program Operations ta-
bles in the AC Characteristics section for parameters,
and Figure 19 section for timing diagrams.
START
Write Erase
Command Sequence
(Notes 1, 2)
Data Poll to Erasing
Bank from System
No
Data = FFh?
Embedded
Erase
algorithm
in progress
Yes
Erasure Completed
Notes:
1. See Table 12 and Table 12 for erase command
sequence.
2. See the section on DQ3 for information on the sector
erase timer.
Erase Suspend/Erase Resume
Commands
The Erase Suspend command, B0h, allows the sys-
tem to interrupt a sector erase operation and then read
data from, or program data to, any sector not selected
for erasure. This command is valid only during the
sector erase operation, including the 50 µs time-out
period during the sector erase command sequence.
The Erase Suspend command is ignored if written dur-
ing the chip erase operation or Embedded Program
algorithm.
When the Erase Suspend command is written during
the sector erase operation, the device requires a typi-
cal of 5 µs (maximum of 20 µs) to suspend the erase
operation. However, when the Erase Suspend com-
mand is written during the sector erase time-out, the
device immediately terminates the time-out period and
suspends the erase operation.
After the erase operation has been suspended, the
device enters the erase-suspend-read mode. The sys-
tem can read data from or program data to any sector
not selected for erasure. (The device “erase sus-
pends” all sectors selected for erasure.) Reading at
any address within erase-suspended sectors pro-
duces status information 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 infor-
mation on these status bits.
After an erase-suspended program operation is com-
plete, the device 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 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 command sequence. Refer to the
Sector Group Protection and Unprotection and Au-
toselect Command Sequence 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 writ-
ing this command. Further writes of the Resume com-
mand are ignored. Another Erase Suspend command
can be written after the chip has resumed erasing.
Figure 7. Erase Operation
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Am49LV6408M
November 5, 2003