EN29LV512
Sector Erase Command Sequence
Sector erase is a six bus cycle operation. The sector erase command sequence is initiated by writing two
un-lock cycles, followed by a set-up command. Two additional unlock write cycles are then followed by the
address of the sector to be erased, and the sector erase command. The Command Definitions table
shows the address and data requirements for the sector erase command sequence.
Once the sector erase operation has begun, only the Erase Suspend command is valid. All other
commands are ignored.
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 using DQ7, DQ6, or
DQ2. Refer to “Write Operation Status” for information on these status bits. Flowchart 4 illustrates the
algorithm for the erase operation. Refer to the Erase/Program Operations tables in the “AC
Characteristics” section for parameters, and to the Sector Erase Operations Timing diagram for timing
waveforms.
Erase Suspend / Resume Command
The Erase Suspend command allows the system 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. The Erase Suspend command is ignored if written during the chip erase operation
or Embedded Program algorithm. Addresses are don’t-cares when writing the Erase Suspend command.
When the Erase Suspend command is written during a sector erase operation, the device requires a
maximum of 20 µs to suspend the erase operation.
After the erase operation has been suspended, the system can read array data from or program data to
any sector not selected for erasure. (The device “erase suspends” all sectors selected for erasure.)
Normal read and write timings and command definitions apply. Reading at any address within erase-
suspended sectors produces status data 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. See “Write Operation Status”
for information on these status bits.
After an erase-suspended program operation is complete, the system can once again read array data
within non-suspended sectors. The system can determine the status of the program operation using the
DQ7 or DQ6 status bits, just as in the standard program operation. See “Write Operation Status” for more
information. The Autoselect command is not supported during Erase Suspend Mode.
The system must write the Erase Resume command (address bits are don’t-care) to exit the erase
suspend mode and continue the sector erase operation. Further writes of the Resume command are
ignored. Another Erase Suspend command can be written after the device has resumed erasing.
WRITE OPERATION STATUS
DQ7:
DATA
Polling
The EN29LV512 provides
DATA
Polling on DQ7 to indicate to the host system the status of the
embedded operations. The
DATA
Polling feature is active during the embedded Programming,
Sector Erase, Chip Erase, Erase Suspend. (See Table 6)
When the embedded Programming is in progress, an attempt to read the device will produce the
complement of the data last written to DQ7. Upon the completion of the embedded Programming,
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
11
©2003 Eon Silicon Solution, Inc., www.essi.com.tw
Rev. B, Issue Date: 2004/01/05
EON [ EON SILICON SOLUTION INC. ]
