AMC0XXCFLKA Datasheet, PDF (15/42 Pages) Advanced Micro Devices – 1, 2, 4, or 10 Megabyte 5.0 V-only Flash Memory PC Card

Sector Erase Suspend
Sector Erase Suspend command allows the user to in-
terrupt the chip and then do data reads (not program)
from a non-busy sector while it is in the middle of a
Sector Erase operation (which may take up to several
seconds). This command is applicable ONLY during
the Sector Erase operation and will be ignored if written
during the chip Erase or Programming operation. The
Erase Suspend command (B0H) will be allowed only
during the Sector Erase Operation that will include the
sector erase time-out period after the Sector Erase
commands (30H). Writing this command during the
time-out will result in immediate termination of the
time-out period. Any subsequent writes of the Sector
Erase command will be ignored as such, but instead
will be taken as the Erase Resume command. Note
that any other commands during the time out will reset
the device to read mode. The addresses are
don’t-cares in writing the Erase Suspend or Erase
Resume commands.
When the Sector Erase Suspend command is written
during a Sector Erase operation, the chip will take be-
tween 0.1 µs to 10 µs to suspend the erase operation
and go into erase suspended read mode (pseudo-read
mode), during which the user can read from a sector
that is NOT being erased. A read from a sector being
erased may result in invalid data. The user must moni-
tor the toggle bit (D6) to determine if the chip has en-
tered the pseudo-read mode, at which time the toggle
bit stops toggling. Note that the user must keep track of
what state the chip is in since there is no external indi-
cation of whether the chip is in pseudo-read mode or
actual read mode. After the user writes the Sector
Erase Suspend command and waits until the toggle bit
stops toggling, data reads from the device may then be
performed. Any further writes of the Sector Erase Sus-
pend command at this time will be ignored.
Every time a Sector Erase Suspend command followed
by an Erase Resume command is written, the internal
(pulse) counters are reset. These counters are used to
count the number of high voltage pulses the memory
cell requires to program or erase. If the count exceeds
a certain limit, then the D5 bit will be set (Exceeded
Time Limit flag). This resetting of the counters is nec-
essary since the Erase Suspend command can poten-
tially interrupt or disrupt the high voltage pulses.
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 ignore. An-
other Sector Erase Suspend command can be written
after the chip has resumed.
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