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CHAPTER 25 DUAL OPERATION FLASH MEMORY
25.4 Checking Automatic Algorithm
Execution Status
25.4.3
Execution Timeout Flag (DQ5)
The execution timeout flag (DQ5) is a hardware sequence flag indicating that
the execution time of the automatic algorithm exceeds a specified time
(required for programming/erasing) in the Flash memory.
■ Execution Timeout Flag (DQ5)
Table 25.4-7 and Table 25.4-8 show the state transition of the execution timeout flag during
normal operation and the one during abnormal operation respectively.
Table 25.4-7
State Transition of Execution Timeout Flag (During Normal Operation)
Programming →
Operating
Programming
state
completed
0 → DATA: 5
DQ5
Table 25.4-8
State Transition of Execution Timeout Flag (During Abnormal Operation)
Operating state
DQ5
● At programming and chip/sector erase
When a read access is made with the automatic write algorithm or the automatic chip/sector
erase algorithm invoked, the flag outputs "0" when the algorithm execution time is within the
specified time (required for programming/erasing) or "1" when it exceeds that time.
The execution time-out flag (DQ5) can be used to check whether programming/erasing has
succeeded or failed regardless of whether the automatic algorithm has been running or
terminated. When the execution timeout flag (DQ5) outputs "1", it can be judged that
programming fails if flash memory program/erase status bit (RDY) in the flash memory status
register (FSR) is "0".
If an attempt is made to write "1" to a Flash memory address holding "0", for example, the
Flash memory is locked, the time limit is exceeded and the execution time-out flag (DQ5)
outputs "1". The state in which the execution time-out flag (DQ5) outputs "1" means that the
Flash memory has not been used correctly; it does not mean that the Flash memory is
defective. When this state occurs, execute the reset command.
542
Chip/sector
Sector erase
erase →
wait →
Erasing
Erasing started
completed
0 → 1
0
Programming
1
FUJITSU SEMICONDUCTOR LIMITED
MB95630H Series
Sector erase →
Sector erase
suspended →
Sector erase
suspended
Erasing resumed
(Sector being
(Sector being
erased)
erased)
0
Chip/sector erase
1
Sector erase
being suspended
(Sector not being
erased)
0
DATA: 5
MN702-00009-1v0-E
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