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16.7 Execution Status of the Automatic Algorithm
Suppose that the data polling and toggle bit functions indica te that the erase algorithm is
running. If this flag is "1" in this case, an internally controlled erase operation has starte d and
succeeding command entries are ignored until the data p olling o r toggle bi t indicates the end of
the erase operation. (Only the input of a temporary erase stop c ode is accepted.)
When this flag is "1", flash memory accepts another sect or erase code e ntry. In this case, it is
recommended to check the status of this flag by software bef ore writing the suc ceeding sector
erase code. If this flag is "1" at the second time of status check, the additional sector erase
code may not be accepted.
When a read operation is performed during a temporary sector eras e stop operation, flash
memory outputs "1" if the address indicated by the address signal is included in the s ector that
is subject to the erase operation. If the address is not include d in the sector that is subj ect to
the erase operation, flash memory outputs the data of b it 3 of the read value at the ad dress
indicated by the address signal.
[bit 2] TOGGL2 (Toggle bit)
Sector erase operation status
Together with toggle bit 6, this toggle bit is used to indicate whether flash memory is subject to
automatic erase operation or temporary erase stop operati on. If dat a i s read co nsecutively from
a sector that is subject to erasing during an automatic erase operation, bit 2 togg les. If data is
consecutively read from a sector that is subject to a temp orary er ase stop o peration when flas h
memory is in temporary erase stop and read mode, bit 2 toggl es also.
If addresses are read consecutively from a sector not subject to a temporary erase stop
operation when flash memory is in temporary erase stop and write mode, bit 2 be comes "1".
Unlike bit 2, bit 6 toggles only in usual write and erase or tempo rary erase stop and write
operations.
For example, bit 2 and bit 6 are used together to detect a temporary e rase stop a nd read mo de
(bit 2 toggles but bit 6 does not). Bit 2 is also used to detec t sectors that are sub ject to erase
operations. If data is read from a sector that is subject to a n erase operation for the flash
memory, bit 2 toggles.