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CHAPTER 19 FLASH MEMORY
❍ Chip/sector erase operation status
When read access is performed while the chip erase/sector erase algorithm is being executed,
flash memory outputs "0" from the target sector (sector erase), regardless of the address
indicated by the address signal. Similarly, flash memory outputs "1" at the end of the chip erase/
sector erase algorithm.
❍ Temporary sector erase stop status
When read access is performed during temporary sector erase stop status, flash memory outputs
"1" when the address indicated by the address signal is included in the sector in erase status. If
the address is not included in the sector in erase status, flash memory outputs bit7 of the read
value to the address. For checking whether a sector is in temporary sector erase stop status and
which sector is in erase status, read this bit and the toggle bit flag.
Note:
Read access to a specified address is ignored while the automatic algorithm is active. Values can be
output to other bits after data polling flag operation terminates in data read operation. Therefore,
when data is to be read after terminating the automatic algorithm, confirm that data polling is
terminated in the current read access.
[bit6] TOGGLE (Toggle bit flag)
This flag is used with the toggle bit function to mainly report that the automatic algorithm is being
executed or terminated.
❍ Write or chip/sector erase operation status
When continuous read operations are performed while the automatic write algorithm or chip/
sector erase algorithm is being executed, flash memory outputs "1" and "0" toggle results to bit6
regardless of the address indicated by the address signal. When continuous read operations are
performed at the end of the automatic write algorithm or chip/sector erase algorithm, flash
memory stops bit6 from toggling and outputs bit6 (DATA: 6) of the data read from the address
indicated by the address signal.
If a write target sector is protected from overwriting 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 overwriting, the toggle bit tries to toggle for about 100 µs and the system returns to
read/reset status without changing data.
❍ 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 bit6 of the read value at the address indicated by the address signal.
[bit5] 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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