EN29LV641H/L EN29LV640U
Reading Array Data
The device is automatically set to reading array data after power up. No commands are required to
retrieve data. The device is also ready to read array data after completing an Embedded Program or
Embedded Erase algorithm.
Following an Sector Erase Suspend command, Sector Erase Suspend mode is entered. The system
can read array data using the standard read timings from sectors other than the one which is being
erase-suspended. If the system reads at an address within erase-suspended sectors, the device
outputs status data. After completing a programming operation in the Sector Erase Suspend mode,
the system may once again read array data with the same exception.
The Reset command must be issued to re-enable the device for reading array data if DQ5 goes high
during an active program or erase operation or while in the autoselect mode. See next section for
details on Reset.
Reset Command
Writing the reset command to the device resets the device to reading array data. Address bits are
don’t-care for this command.
The reset command may be written between the cycle sequences in an erase command sequence
before erasing begins. This resets the device to reading array data. Once erasure begins, however,
the device ignores reset commands until the operation is complete. The reset command may be
written between the cycle sequences in a program command sequence before programming begins.
This resets the device to reading array data (also applies to programming in Sector Erase Suspend
mode). Once programming begins, however, the device ignores reset commands until the operation
is complete.
The reset command may be written between the cycle sequences in an autoselect command
sequence. Once in the autoselect mode, the reset command must be written to return to reading
array data.
If DQ5 goes high during a program or erase operation, writing the reset command returns the device
to reading array data (also applies in Sector Erase Suspend mode).
Autoselect Command Sequence
The autoselect command sequence allows the host system to access the manufacturer and devices
ID codes, and determine whether or not a sector group is protected. The Command Definitions table
shows the address and data requirements. This is an alternative to the method that requires VID on
address bit A9 and is intended for commercial programmers.
Two unlock cycles followed by the autoselect command initiate the autoselect command sequence.
Autoselect mode is then entered and the system may read at addresses shown in Table 9 any
number of times, without needing another command sequence.
The system must write the reset command to exit the autoselect mode and return to reading array
data.
Word Programming Command
Programming is performed by using a four-bus-cycle operation (two unlock write cycles followed by
the Program Setup command and Program Data Write cycle). When the program command is
executed, no additional CPU controls or timings are necessary. An internal timer terminates the
program operation automatically. Address is latched on the falling edge of CE# or WE#, whichever is
last; data is latched on the rising edge of CE# or WE#, whichever is first.
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2005 Eon Silicon Solution, Inc., www.essi.com.tw
18
Rev. B, Issue Date: 2005/06/27
EON [ EON SILICON SOLUTION INC. ]
