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CHAPTER 25 DUAL OPERATION FLASH MEMORY
25.4 Checking Automatic Algorithm
Execution Status
25.4.5
Toggle Bit2 Flag (DQ2)
The toggle bit2 flag (DQ2) is a hardware sequence flag using the toggle bit
function to indicate whether a read address is an erase target sector in the
sector erase suspend state and whether output data is toggled.
■ Toggle Bit2 Flag (DQ2)
Table 25.4-11 and Table 25.4-12 show the state transition of the toggle bit2 flag during normal
operation and the one during abnormal operation respectively.
Table 25.4-11 State Transition of Toggle Bit2 Flag (During Normal Operation)
Programming →
Operating
Programming
state
completed
0 → DATA: 2
DQ2
Table 25.4-12 State Transition of Toggle Bit2 Flag (During Abnormal Operation)
Operating state
DQ2
● At chip/sector erase
•
When read accesses are continuously made to a sector to be erased while the automatic
chip/sector erase algorithm is being executed, the Flash memory toggles the output between
"1" and "0" at each read access.
•
When read accesses are continuously made to a sector not to be erased while the automatic
chip/sector erase algorithm is being executed, the Flash memory outputs bit2 (DATA: 2) of
the value read from a read address of each read access.
● At sector erase suspension
•
With a sector erase operation suspended, when read accesses are continuously made to a
sector to be erased, the Flash memory toggles the output between "1" and "0" whenever a
read access is made.
•
With a sector erase operation suspended, when read accesses are continuously made to a
sector not to be erased, the Flash memory outputs bit2 (DATA: 2) of the read value of a
read address whenever a read access is made.
544
Chip/sector
Sector erase
erase →
wait →
Erasing
Erasing started
completed
Toggle → 1
Toggle
Programming
0
FUJITSU SEMICONDUCTOR LIMITED
MB95630H Series
Sector erase →
Sector erase
suspended →
Sector erase
suspended
Erasing resumed
(Sector being
(Sector being
erased)
erased)
Toggle
Toggle
Chip/sector erase
Toggle
Sector erase
being suspended
(Sector not being
erased)
DATA: 2
MN702-00009-1v0-E
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