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MB95630H Series
25.4.1
Data Polling Flag (DQ7)
The data polling flag (DQ7) is a hardware sequence flag indicating that the
automatic algorithm is being executing or has been completed using the data
polling function.
■ Data Polling Flag (DQ7)
Table 25.4-3 and Table 25.4-4 show the state transition of the data polling flag during normal
operation and the one during abnormal operation respectively.
Table 25.4-3
State Transition of Data Polling Flag (During Normal Operation)
Programming →
Operating
Programming
state
completed
DQ7 → DATA: 7
DQ7
Table 25.4-4
State Transition of Data Polling Flag (During Abnormal Operation)
Operating state
DQ7
● At programming
When read access takes place during execution of the automatic write algorithm, the Flash
memory outputs the inverted value of bit7 in the last data written to DQ7.
If read access takes place on completion of the automatic write algorithm, the Flash memory
outputs bit7 of the value read from the read-accessed address to DQ7.
● At chip/sector erase
When read access is made to the sector currently being erased during execution of the chip/
sector erase algorithm, bit7 of Flash memory outputs "0". Bit7 of Flash memory outputs "1"
upon completion of chip/sector erase.
● At sector erase suspension
•
When read access takes place with a sector erase operation suspended, the Flash memory
outputs "0" to DQ7 if the read address is the sector being erased. If not, the Flash memory
outputs bit7 (DATA:7) of the value read from the read address to DQ7.
•
Referring the data polling flag (DQ7) together with the toggle bit flag (DQ6) permits a
decision on whether Flash memory is in the sector erase suspended state or which sector is
being erased.
MN702-00009-1v0-E
CHAPTER 25 DUAL OPERATION FLASH MEMORY
Chip/sector
Sector erase
erase →
wait →
Erasing
Erasing started
completed
0 → 1
0
Programming
DQ7
FUJITSU SEMICONDUCTOR LIMITED
25.4 Checking Automatic Algorithm
Sector erase →
Sector erase
suspended →
Sector erase
suspended
Erasing resumed
(Sector being
(Sector being
erased)
erased)
0
Chip/sector erase
0
Execution Status
Sector erase
being suspended
(Sector not being
erased)
0
DATA: 7
539
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