Fujitsu FR81S User Manual
CHAPTER 45: FLASH MEMORY
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : FLASH MEMORY
FUJITSU SEMICONDUCTOR CONFIDENTIAL
44
Notes:
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The time required to erase the sector is [(sector erase time + sector write time (pre- program)) × number
of sectors].
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When the sector erase operation finishes, the flash memory returns to the read/reset state.
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See "5.3. Automatic Algorithm" for details on the sector erase command.
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Because the DPOLL bit and the TLOV bit of the hardware sequence flag change at the same time, even
when TLOV bit is "1", it is necessary to confirm again.
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When the TOGG1 bit and the TLOV bit of the hardware sequence flag change to "1", toggle operation
stops at the same time. Therefore, it is necessary to confirm the TOGG1 bit again even the TLOV bit is
"1".
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If a command other than the sector erase command is issued during sector erase including the timeout
period, the flash memory returns to the read/reset state. In this case, because the flash memory is reset,
the previously issued command or multiple sector erase commands become invalid. To erase the sector,
reissue the sector erase commands from the beginning.
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When the automatic erase algorithm is started, "0" is written to the cells to erase in flash memory before
erasing the sector, and there is no need to write to flash memory before erasing the sector to verify the
margins (preprogramming). Furthermore, while verifying the margin, there is no need to control the flash
memory externally.
MB91520 Series
MN705-00010-1v0-E
1965