AM29LV640MH SPANSION [SPANSION], AM29LV640MH Datasheet - Page 34

• Manufacturer Part Number: AM29LV640MH
• Description: 64 Megabit (4 M x 16-Bit/8 M x 8-Bit) MirrorBit 3.0 Volt-only Uniform Sector Flash Memory with VersatileI/O Control
• Manufacturer: SPANSION [SPANSION]

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 sec-
tor erase operation, including the 50 µs time-out pe-
riod during the sector erase command sequence. The
Erase Suspend command is ignored if written during
the chip erase operation or Embedded Program
algorithm.
When the Erase Suspend command is written during
the sector erase operation, the device requires a max-
imum of 20 (typical 5 µs) to suspend the erase opera-
tion. However, when the Erase Suspend command is
written during the sector erase time-out, the device im-
mediately terminates the time-out period and sus-
pends 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
mation on these status bits.
32
Write Operation Status
section for infor-
D A T A S H E E T
Am29LV640MH/L
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
information.
In the erase-suspend-read mode, the system can also
issue the autoselect command sequence. Refer to the
Autoselect Mode
sections for details.
To resume the sector erase operation, the system
must write the Erase Resume command. Further
writes of the Resume command are ignored. Another
Erase Suspend command can be written after the chip
has resumed erasing.
Note: During an erase operation, this flash device per-
forms multiple internal operations which are invisible
to the system. When an erase operation is suspended,
any of the internal operations that were not fully com-
pleted must be restarted. As such, if this flash device
is continually issued suspend/resume commands in
rapid succession, erase progress will be impeded as a
function of the number of suspends. The result will be
a longer cumulative erase time than without suspends.
Note that the additional suspends do not affect device
reliability or future performance. In most systems rapid
erase/suspend activity occurs only briefly. In such
cases, erase performance will not be significantly im-
pacted.
Write Operation Status
and
Autoselect Command Sequence
December 14, 2005
section for more