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COMMAND DEFINITIONS
Writing specific address and data commands or
sequences into the command register initiates
device operations. Table 5 defines the valid register
command sequences. Note that writing incorrect
address and data values or writing them in the
improper sequence may place the device in an
unknown state. A reset command is required to
return the device to normal operation.
the Device Bus Operations section for more informa-
tion.The Read-Only Operations table provides the
read parameters, and Fig. 16 shows the timing dia-
gram
RESET COMMAND
Writing the reset command resets the device to the
read or erase-suspend-read mode. Address bits are
don’t cares for this command.
All addresses are latched on the falling edge of WE#
or CE#, whichever happens later. All data is latched
on the rising edge of WE# or CE#, whichever hap-
pens first. Refer to the AC Characteristics section for
timing diagrams.
The reset command may be written between the
sequence cycles in an erase command sequence
before erasing begins. This resets the device to
which the system was writing to the read mode.
Once erasure begins, however, the device ignores
reset commands until the operation is complete.
READING ARRAY DATA
The device is automatically set to reading array data
after device power-up. No commands are required
to retrieve data. The device is ready to read array
data after completing an Embedded Program or
Embedded Erase algorithm.
The reset command may be written between the
sequence cycles in a program command sequence
before programming begins. This resets the device
to which the system was writing to the read mode. If
the program command sequence is written to a sec-
tor that is in the Erase Suspend mode, writing the
reset command returns the device to the erase-sus-
pend-read mode. Once programming begins, how-
ever, the device ignores reset commands until the
operation is complete.
After the device accepts an Erase Suspend com-
mand, the device enters the erase-suspend-read
mode, after which the system can read data from
any non-erase-suspended sector. After completing a
programming operation in the Erase Suspend mode,
the system may once again read array data with the
same exception. See the Erase Suspend/Erase
Resume Commands section for more information.
The reset command may be written between the
sequence cycles in an autoselect command
sequence. Once in the autoselect mode, the reset
command must be written to return to the read
mode. If the device entered the autoselect mode
while in the Erase Suspend mode, writing the reset
command returns the device to the erase-suspend-
read mode.
The system must issue the reset command to return
the device to the read (or erase-suspend-read)
mode if DQ5 goes high during an active program or
erase operation, or if the device is in the autoselect
mode. See the next section, Reset Command, for
more information.
If DQ5 goes high during a program or erase opera-
tion, writing the reset command returns the device to
the read mode (or erase-suspend-read mode if the
device was in Erase-Suspend).
See also Requirements for Reading Array Data in
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Rev.0B January 5, 2006
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