Fujitsu FR60 Hardware Manual page 569

■ Temporarily Stop Erase
The temporarily stop erase command temporarily stops the automatic algorithm in flash memory when the
user is erasing the data of a sector, thereby making it possible to write data to and read data from the other
sectors that is not subject to the erase operation. This command is valid only during the sector erase
operation and ignored during chip erase and write operations.
The temporarily stop erase command (B0 ) is effective only during sector erasure operation that includes
H
the sector erase time-out period after a sector erase command (30 ) is issued.
H
When this command is entered within the time-out period, waiting for time-out ends and the erase
operation is suspended. The erase operation is restarted when a restart erase command was written. The
temporarily stop erase and restart erase commands can be entered with any address.
When a temporarily stop erase command is entered during sector erase operation, the flash memory needs a
maximum of 20 µs to stop the erase operation. When flash memory enters temporary erase stop mode, a
ready or busy signal is output, bit 7 outputs "1", and bit 6 stops to toggle. For checking whether the erase
operation has stopped, enter the address of the sector whose data is being erased and read the values of bit 6
and bit 7. At this time, another temporarily stop erase command entry is ignored.
When the erase operation stops, flash memory enters the temporary erase stop and read mode. Data reading
is enabled in this mode for sectors that are not subject to temporary erase. Other than that, there is no
difference from the standard read operation. In this mode, bit 2 toggles for consecutive reading operations
from sectors subject to temporary erase stop.
After the temporary erase stop and read mode is entered, the user can write to flash memory by writing a
write command sequence. The write mode in this case is the temporary erase stop and write mode. In this
mode, data write operations become valid for sectors that are not subject to temporary erase stop. Other
than that, there is no difference from the standard byte writing operation. In this mode, bit 2 toggles for
consecutive reading operations from sectors that are subject to temporary erase stop. The temporary erase
stop bit (bit 6) can be used to detect this operation.
Note that bit 6 can be read from any address, but bit 7 must be read from write addresses.
To restart the sector erase operation, a restart erase command (30 ) must be entered. Another restart
H
command entry is ignored in this case. On the other hand, a temporarily stop erase command can be entered
after flash memory restarts the erase operation.
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