Fujitsu MB96300 series Hardware Manual page 870

CHAPTER 33 FLASH MEMORY
33.6.1 Data Polling Flag (DQ7)
The data polling flag (DQ7) uses the data polling function to post that the automatic
algorithm is being executed or has terminated
■ Data polling flag (DQ7)
Table 33.6-3 Data polling flag state transitions (state change for normal operation) and Table 33.6-4 Data
polling flag state transitions (state change for abnormal operation)"Data polling flag state transitions (state
change for abnormal operation)" list the state transitions of the data polling flag.
Table 33.6-3 Data polling flag state transitions (state change for normal operation)
Operating Write -->
state Completed
DQ7 DQ7 -->
DATA:7
Table 33.6-4 Data polling flag state transitions (state change for abnormal operation)
Operating state
DQ7
●
Write
Read-access during execution of the automatic write algorithm causes the flash memory to output the
opposite data of bit 7 last written, regardless of the value at the address specified by the address signal.
Read-access at the end of the automatic write algorithm causes the flash memory to output bit 7 of the read
value of the address specified by the address signal.
●
Chip/sector erase
For a sector erase, read-access during execution of the chip erase/sector erase algorithm causes the flash
memory to output 0 from the sector currently being erased. For a chip erase, read-access causes the flash
memory to output 0 regardless of the value at the address specified by the address signal. Read-access at
the end of the automatic write algorithm causes the flash memory to output 1 in the same way.
●
Sector erase suspend
Read-access during a sector erase suspend causes the flash memory to output 1 if the address specified by
the address signal belongs to the sector being erased. The flash memory outputs bit 7 (DATA: 7) of the
read value at the address specified by the address signal if the address specified by the address signal does
not belong to the sector being erased. Referencing this flag together with the toggle bit flag (DQ6) enables
a decision to be made on whether the flash memory is in the erase suspended state and which sector is
862
Chip/sector Sector erase
erase --> wait
Completed --> Started
0 --> 1 1
Write
DQ7
Sector erase
--> Erase
suspend (sector
being erased)
0 --> 1
Chip/sector
erase
0
Sector erase Sector erase
suspend --> suspended
Restarted (sector (sector not being
being erased) erased)
1 --> 0 DATA:7