Fujitsu FR60 Hardware Manual page 574

CHAPTER 17 FLASH MEMORY
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Sector erase operation 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 that is subject to the erase
operation. If the address is not included in the sector that is subject to the erase operation, flash memory
outputs the data of bit 3 (DATA:3) of the read value at the address indicated by the address signal.
[bit 6] TOGGL2 (Toggle bit flag 2)
Together with toggle bit 6, this toggle bit flag is used with the toggle bit function to report whether flash
memory is under automatic erase operation or in temporary erase stop status.
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Write or chip/sector erase operation status
This bit toggles the same way as bit 2.
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Temporary sector erase stop operation status
When continuous read access is performed from a sector in temporary erase stop status while flash memory
is in temporary erase stop status and read mode, bit 2 toggles. When continuous read access is performed
from a sector not subject to a temporary erase stop operation while flash memory is in temporary erase stop
status and write mode, bit 2 becomes "1." Unlike bit 2, bit 6 only toggles in normal write and erase
operations, or in temporary erase stop status and write operation.
Reference:
For example, bit 2 and bit 6 are used together to detect a temporary erase stop and read mode (bit 2
toggles but bit 6 does not). Bit 2 is also used to detect sectors that are subject to erase operations. If
data is read from a sector that is subject to an erase operation for the flash memory, bit 2 toggles.
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