Fujitsu MB89202 Computer Hardware User Manual


 
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CHAPTER 17 FLASH MEMORY
17.4.4 Toggle Bit-2 Flag (DQ2)
The toggle bit-2 flag (DQ2) is used to detect that flash memory is performing an
automatic erase operation, together with the toggle bit.
Automatic Write/Erase
Making successive read accesses while the automatic erasing algorithm is being performed toggles flash
memory and makes it output 1 and then 0, in turn, regardless of the specified address. Making successive
read accesses while the automatic writing algorithm is being performed toggles flash memory and makes it
output 1 regardless of the specified address.
Making successive read accesses when the automatic writing/erasing algorithm ends makes flash memory
to stop bit2 toggle and outputs the value of bit2 (DATA:6) corresponding to the value read from the
specified address. The toggle bit becomes effective after the last write cycle in each command sequence.