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Document Number: 002-00856 Rev. *E
S29JL064J
10.6
Chip Erase Command Sequence
Chip erase is a six bus cycle operation. The chip erase command sequence is initiated by writing two unlock cycles, followed by a
set-up command. Two additional unlock write cycles are then followed by the chip erase command, which in turn invokes the
Embedded Erase algorithm. The device does
not
require the system to preprogram prior to erase. The Embedded Erase algorithm
automatically preprograms and verifies the entire memory for an all zero data pattern prior to electrical erase. The system is not
required to provide any controls or timings during these operations.
shows the address and data requirements for
the chip erase command sequence.
When the Embedded Erase algorithm is complete, that bank returns to the read mode and addresses are no longer latched. The
system can determine the status of the erase operation by using DQ7, DQ6, DQ2, or RY/BY#. Refer to
for information on these status bits.
Any commands written during the chip erase operation are ignored. However, note that a
hardware reset
immediately terminates
the erase operation. If that occurs, the chip erase command sequence should be reinitiated once that bank has returned to reading
array data, to ensure data integrity.
Note that the Secured Silicon Region, autoselect, and CFI functions are unavailable when an
erase operation is in progress.
illustrates the algorithm for the erase operation. Refer to
for
parameters, and
for timing diagrams.
10.7
Sector Erase Command Sequence
Sector erase is a six bus cycle operation. The sector erase command sequence is initiated by writing two unlock cycles, followed by
a set-up command. Two additional unlock cycles are written, and are then followed by the address of the sector to be erased, and
the sector erase command.
shows the address and data requirements for the sector erase command sequence.
The device does
not
require the system to preprogram prior to erase. The Embedded Erase algorithm automatically programs and
verifies the entire sector for an all zero data pattern prior to electrical erase. The system is not required to provide any controls or
timings during these operations.
After the command sequence is written, a sector erase time-out of 50 µs occurs. During the time-out period, additional sector
addresses and sector erase commands may be written. However, these additional erase commands are only one bus cycle long
and should be identical to the sixth cycle of the standard erase command explained above. Loading the sector erase buffer may be
done in any sequence, and the number of sectors may be from one sector to all sectors. The time between these additional cycles
must be less than 50 µs, otherwise erasure may begin. Any sector erase address and command following the exceeded time-out
may or may not be accepted. It is recommended that processor interrupts be disabled during this time to ensure all commands are
accepted. The interrupts can be re-enabled after the last Sector Erase command is written.
If any command other than 30h, B0h,
F0h is input during the time-out period, the normal operation will not be guaranteed.
The system must rewrite the command
sequence and any additional addresses and commands.
The system can monitor DQ3 to determine if the sector erase timer has timed out (See the section on DQ3: Sector Erase Timer.).
The time-out begins from the rising edge of the final WE# or CE# pulse (first rising edge) in the command sequence.
When the Embedded Erase algorithm is complete, the bank returns to reading array data and addresses are no longer latched. Note
that while the Embedded Erase operation is in progress, the system can read data from the non-erasing bank. The system can
determine the status of the erase operation by reading DQ7, DQ6, DQ2, or RY/BY# in the erasing bank. Refer to
for information on these status bits.
Once the sector erase operation has begun, only the Erase Suspend command is valid. All other commands are ignored. However,
note that a
hardware reset
immediately
terminates the erase operation. If that occurs, the sector erase command sequence should
be reinitiated once that bank has returned to reading array data, to ensure data integrity.
Note that the Secured Silicon Region,
autoselect, and CFI functions are unavailable when an erase operation is in progress.
illustrates the algorithm for the erase operation. Refer to
for
parameters, and
for timing diagrams.