E S I
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sequence should be reinitiated once the device has
returned to reading array data, to ensure data integ-
rity.
After an erase-suspended program operation is
complete, the device returns to the erase-suspend-
read mode. The system can determine the status for
the program operation using the DQ7 or DQ6 status
bits, just as in the standard Byte Program operation.
Refer to the Write Operation Status section for more
information.
Fig. 7 illustrates the algorithm for the erase opera-
tion. Refer to the Erase and Program Operations
tables in the AC Characteristics section for parame-
ters, and Fig. 21 section for timing diagrams.
Autoselect during Erase-Suspend- Read
Mode
ERASE SUSPEND/ERASE RESUME
In the erase-suspend-read mode, the system can
also issue the autoselected command sequence.
Refer to the Autoselect Mode and Autoselect Com-
mand Sequence section for details (Table 5).
An erase operation is a long-time operation so that
two useful commands are provided in the
ES29LV400 device Erase Suspend and Erase
Resume Commands. Through the two commands,
erase operation can be suspended for a while and
the suspended operation can be resumed later when
it is required. While the erase is suspended, read or
program operations can be performed by the system.
Erase Resume Command
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.
Erase Suspend Command, (B0h)
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 dur-
ing the sector erase operation, including the 50us
time-out period during the sector erase command
sequence. The Erase Suspend command is ignored
if written during the chip erase operation or Embed-
ded Program algorithm. When the Erase Suspend
command is written during the sector erase opera-
tion, the device requires a maximum of 20us to sus-
pend the erase operation. However, when the Erase
Suspend command is written during the sector erase
time-out, the device immediately terminates the time-
out period and suspends the erase operation.
Read and Program during Erase-Suspend-
Read Mode
After the erase operation has been suspended, the
device 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
suspends” all sectors selected for erasure.)
Reading at any address within erase-suspended sec-
tors produces 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 sec-
tion for information on these status bits (Table 6).
19
Rev.0B January 5, 2006
ES29LV400E
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
