Execution Time-Out Flag (Dq5) - Fujitsu F2MC-8FX Hardware Manual

CHAPTER 28 256-KBIT FLASH MEMORY
28.5.3

Execution Time-out Flag (DQ5)

The execution time-out flag (DQ5) is a hardware sequence flag indicating that the
automatic algorithm has been executed beyond the specified time (required for
programming/erasing) internal to the flash memory.
Execution Time-out Flag (DQ5)
Table 28.5-7 and Table 28.5-8 show the state transition of the execution time-out flag.
Table 28.5-7 State Transition of Execution Time-out Flag (During Normal Operation)
Operating state
Table 28.5-8 State Transition of Execution Time-out Flag (During Abnormal Operation)
At programming and chip erasing
When read access is made with the write or chip-erase automatic 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
time-out flag (DQ5) outputs "1", it indicates that programming has failed if the automatic algorithm is still
running for the data polling or toggle bit function.
If an attempt is made to write "1" to a flash memory address holding "0", for example, the flash memory is
locked, preventing the automatic algorithm from being terminated and valid data from being output from
the data polling flag (DQ7). As the toggle bit flag (DQ6) does not stop toggling, 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.
532
Programming → Programming completed
DQ5
Operating state
DQ5
0 → DATA: 5
Programming
1
Chip erasing → Erasing completed
0 → 1
Chip erasing
1