LH28F800SG-L データシートの表示（PDF） - Sharp Electronics
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LH28F800SG-L Datasheet PDF : 45 Pages
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the device automatically outputs status register data
when read (see Fig. 3). The CPU can detect block
erase completion by analyzing the output data of
the RY/BY# pin or status register bit SR.7.
When the block erase is complete, status register
bit SR.5 should be checked. If a block erase error
is detected, the status register should be cleared
before system software attempts corrective actions.
The CUI remains in read status register mode until
a new command is issued.
This two-step command sequence of set-up
followed by execution ensures that block contents
are not accidentally erased. An invalid Block Erase
command sequence will result in both status
register bits SR.4 and SR.5 being set to "1". Also,
reliable block erasure can only occur when VCC =
VCC1/2/3/4 and VPP = VPPH1/2/3. In the absence of
this high voltage, block contents are protected
against erasure. If block erase is attempted while
VPP ≤ VPPLK, SR.3 and SR.5 will be set to "1".
Successful block erase requires that the
corresponding block lock-bit be cleared or, if set,
that WP# = VIH or RP# = VHH. If block erase is
attempted when the corresponding block lock-bit is
set and WP# = VIL and RP# = VIH, SR.1 and SR.5
will be set to "1". Once permanent lock-bit is set,
the blocks which have been set block lock-bit are
unable to erase forever. Block erase operations
with VIH < RP# < VHH produce spurious results and
should not be attempted.
4.6 Word Write Command
Word write is executed by a two-cycle command
sequence. Word write setup (standard 40H or
alternate 10H) is written, followed by a second write
that specifies the address and data (latched on the
rising edge of WE#). The WSM then takes over,
controlling the word write and write verify algorithms
internally. After the word write sequence is written,
the device automatically outputs status register data
when read (see Fig. 4). The CPU can detect the
LH28F800SG-L/SGH-L (FOR TSOP, CSP)
completion of the word write event by analyzing the
RY/BY# pin or status register bit SR.7.
When word write is complete, status register bit
SR.4 should be checked. If word write error is
detected, the status register should be cleared. The
internal WSM verify only detects errors for "1"s that
do not successfully write to "0"s. The CUI remains
in read status register mode until it receives another
command.
Reliable word writes can only occur when VCC =
VCC1/2/3/4 and VPP = VPPH1/2/3. In the absence of
this high voltage, memory contents are protected
against word writes. If word write is attempted while
VPP ≤ VPPLK, status register bits SR.3 and SR.4 will
be set to "1". Successful word write requires that
the corresponding block lock-bit be cleared or, if
set, that WP# = VIH or RP# = VHH. If word write is
attempted when the corresponding block lock-bit is
set and WP# = VIL and RP# = VIH, SR.1 and SR.4
will be set to "1". Once permanent lock-bit is set,
the blocks which have been set block lock-bit are
unable to write forever. Word write operations with
VIH < RP# < VHH produce spurious results and
should not be attempted.
4.7 Block Erase Suspend Command
The Block Erase Suspend command allows block
erase interruption to read or word write data in
another block of memory. Once the block erase
process starts, writing the Block Erase Suspend
command requests that the WSM suspend the
block erase sequence at a predetermined point in
the algorithm. The device outputs status register
data when read after the Block Erase Suspend
command is written. Polling status register bits
SR.7 and SR.6 can determine when the block
erase operation has been suspended (both will be
set to "1"). RY/BY# will also transition to VOH.
Specification tWHRH2 defines the block erase
suspend latency.
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