MBM29F800TA-55/-70/-90/MBM29F800BA-55/-70/-90
at which time the device returns to the read mode. Data polling must be performed at an address within any of
the sectors being erased.
“Embedded EraseTM Algorithm” in ■ FLOW CHART illustrates the Embedded Erase Algorithm using typical
command strings and bus operations.
Erase Suspend
The Erase Suspend command allows the user to interrupt a Sector Erase operation and then perform data reads
from or programs to a sector not being erased. This command is applicable ONLY during the Sector Erase
operation which includes the time-out period for sector erase. The Erase Suspend command will be ignored if
written during the Chip Erase operation or Embedded Program Algorithm. Writting the Erase Suspend command
during the Sector Erase time-out results in immediate termination of the time-out period and suspension of the
erase operation.
Writing the Erase Resume command resumes the erase operation. The addresses are “don’t cares” when writing
the Erase Suspend or Erase Resume command.
When the Erase Suspend command is written during the Sector Erase operation, the device will take a maximum
of 20 µs to suspend the erase operation. When the device has entered the erase-suspended mode, the RY/BY
output pin and the DQ7 bit will be at logic “1”, and DQ6 will stop toggling. The user must use the address of the
erasing sector for reading DQ6 and DQ7 to determine if the erase operation has been suspended. Further writes
of the Erase Suspend command are ignored.
When the erase operation has been suspended, the device defaults to the erase-suspend-read mode. Reading
data in this mode is the same as reading from the standard read mode except that the data must be read from
sectors that have not been erase-suspended. Successively reading from the erase-suspended sector while the
device is in the erase-suspend-read mode will cause DQ2 to toggle. (See “DQ2 Toggle Bit II”).
After entering the erase-suspend-read mode, the user can program the device by writing the appropriate
command sequence for Program. This Program mode is known as the erase-suspend-program mode. Again,
programming in this mode is the same as programming in the regular Program mode except that the data must
beprogrammedtosectorsthatarenoterase-suspended. Successivelyreadingfromtheerase-suspendedsector
whilethedeviceisintheerase-suspend-programmodewillcauseDQ2 totoggle. Theendoftheerase-suspended
Program operation is detected by the RY/BY output pin, Data polling of DQ7, or by the Toggle Bit I (DQ6) which
is the same as the regular Program operation. Note that DQ7 must be read from the Program address while DQ6
can be read from any address.
To resume the operation of Sector Erase, the Resume command (30h) should be written. Any further writes of
the Resume command at this point will be ignored. Another Erase Suspend command can be written after the
chip has resumed erasing.
17
SPANSION [ SPANSION ]
