Fujitsu FR60 Hardware Manual page 573

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Temporary sector erase stop status
When a read operation is performed during a temporary sector erase stop operation, flash memory outputs
"1" if the address indicated by the address signal is included in the sector in erase state. If the address is not
included in the sector in erase state, flash memory outputs the data of bit 6 (DATA:6) of the read value at
the address indicated by the address signal.
Reference:
If a write target sector is protected from rewriting during a write operation, the toggle bit tries to
toggle for about 2 µs and stops toggling without changing data. If all selected sectors are protected
from rewriting during a erase operation, the toggle bit tries to toggle for about 100 µs and the system
returns to read/reset status without changing data.
[bit 5] TLOVER (Time limit over flag)
This flag is used to report that a time (number of internal pulses) specified internally with flash memory is
exceeded while the automatic algorithm is being executed.
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Write or chip/sector erase operation status
When read access is performed within a specified time (necessary for write or erase) after activating the
automatic write or chip/sector erase algorithm, flash memory outputs "0." If read access is performed
beyond the specified time, flash memory outputs "1." Because these output operations are not affected by
whether the automatic algorithm is being executed or terminated, these operations can be used to check
whether write or erase operation is successful. If flash memory outputs "1" while the automatic algorithm is
being executed with the data polling function or toggle bit function, consider the write operation to be
unsuccessful.
For example, when "1" is written to a flash memory address where "0" is written, failure occurs. Flash
memory is locked and the automatic algorithm is not terminated. Thus, valid data is not outputted from the
data polling flag. The toggle bit flag does not stop toggling, the time limit is exceeded, and "1" is outputted
to the TLOVER flag. This status indicates that flash memory was not used correctly, not that it was
defective. Execute a reset command.
[Bit 4] SETIMR Sector erase timer flag
This flag is used to report that sector erasure is being awaited after starting a sector erase command.
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Sector erase operation status
When read access is performed within a sector erase wait period after starting a sector erase command,
flash memory outputs "0" regardless of the address indicated by the address signal of the target sector. If
read access is performed beyond the wait period, flash memory outputs "1" regardless of the address.
When "1" is set in this flag while the data polling or toggle bit function indicates that the automatic erase
algorithm is being executed, an internally controlled erase operation has started. The writing of subsequent
sector erase code and commands other than erase temporary stop is ignored until erase operation
terminates.
When this flag is "0", flash memory accepts another sector erase code entry. In this case, it is recommended
to check the status of this flag by software before writing the succeeding sector erase code. If this flag is
"1" at the second time of status check, the additional sector erase code may not be accepted.
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