HY29F080 Datasheet, PDF (13/38 Pages) Hynix Semiconductor – 8 Megabit (1M x 8), 5 Volt-only, Flash Memory

sector is to be erased. As described later in this
section, multiple sectors can be specified for era-
sure with a single command sequence. During
sector erase, all specified sectors are erased se-
quentially. The data in sectors not specified for
erasure, as well as the data in any sectors speci-
fied for erasure but located within protected sec-
tor groups, is not affected by the sector erase op-
eration.
The Sector Erase command sequence starts the
Automatic Erase algorithm, which preprograms
and verifies the specified unprotected sectors for
an all zero data pattern prior to electrical erase.
The device then provides the required number of
internally generated erase pulses and verifies cell
erasure within the proper cell margins. The host
system is not required to provide any controls or
timings during these operations.
After the sector erase data cycle (the sixth bus
cycle) of the command sequence is issued, a sec-
tor erase time-out of 50 µs (typical), measured from
the rising edge of the final WE# pulse in that bus
cycle, begins. During this time, an additional sec-
tor erase data cycle, specifying the sector address
of another sector to be erased, may be written
into an internal sector erase buffer. This buffer
may be loaded in any sequence, and the number
of sectors specified may be from one sector to all
sectors. The only restriction is that the time be-
tween these additional data cycles must be less
than 50 µs, otherwise erasure may begin before
the last data cycle is accepted. To ensure that all
data cycles are accepted, it is recommended that
host processor interrupts be disabled during the
time that the additional cycles are being issued
and then be re-enabled afterwards.
Note: The device is capable of accepting three ways
of invoking Erase Commands for additional sectors
during the time-out window. The preferred method,
described above, is the sector erase data cycle after
the initial six bus cycle command sequence. How-
ever, the device also accepts the following methods
of specifying additional sectors during the sector
erase time-out:
n Repeat the entire six-cycle command sequence, speci-
fying the additional sector in the sixth cycle.
n Repeat the last three cycles of the six-cycle command
sequence, specifying the additional sector in the third
cycle.
If all sectors scheduled for erasing are within pro-
tected sector groups, the device returns to read-
ing array data after approximately 100 µs. If at
Rev. 6.1/May 01
HY29F080
least one selected sector is not protected, the
erase operation erases the unprotected sectors,
and ignores the command for the selected sec-
tors that are protected.
The system can monitor DQ[3] to determine if the
50 µs sector erase time-out has expired, as de-
scribed in the Write Operation Status section. If
the time between additional sector erase data
cycles can be insured to be less than the time-
out, the system need not monitor DQ[3].
Any command other than Sector Erase or Erase
Suspend during the time-out period resets the
device to reading array data. The system must
then rewrite the command sequence, including any
additional sector erase data cycles. Once the
sector erase operation itself has begun, only the
Erase Suspend command is valid. All other com-
mands are ignored.
As for the Chip Erase command, note that a hard-
ware reset immediately terminates the erase op-
eration. To ensure data integrity, the aborted Sec-
tor Erase command sequence should be reissued
once the reset operation is complete.
When the Automatic Erase algorithm terminates,
the device returns to the Read mode. Several
methods are provided to allow the host to deter-
mine the status of the erase operation, as de-
scribed in the Write Operation Status section.
Figure 6 illustrates the Sector Erase procedure.
Erase Suspend/Erase Resume Commands
The Erase Suspend command allows the system
to interrupt a sector erase operation to read data
from, or program data in, any sector not being
erased. The command causes the erase opera-
tion to be suspended in all sectors selected for
erasure. This command is valid only during the
sector erase operation, including during the 50 µs
time-out period at the end of the initial command
sequence and any subsequent sector erase data
cycles, and is ignored if it is issued during chip
erase or programming operations.
The HY29F080 requires a maximum of 15 µs to
suspend the erase operation if the Erase Suspend
command is issued during active sector erasure.
However, if the command is written during the time-
out, the time-out is terminated and the erase op-
eration is suspended immediately. Any sub-
sequent attempts to specify additional sectors for
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