Data Polling Flag (Dq7) - Fujitsu F2MC-16LX Hardware Manual

CHAPTER 23 1M-BIT FLASH MEMORY

23.6.1 Data Polling Flag (DQ7)

Using the data polling function, the data polling flag (DQ7) notifies an operator that the
automatic algorithm execution is ongoing or ends.
■ Data Polling Flag (DQ7)
Table 23.6-3 and Table 23.6-4 list the transitions of data polling flag statuses.
Table 23.6-3 Status Transition of the Data Polling Flag (Status Changes At Normal Operation)
Operation Writing -->
status completion
DQ7 -->
DQ7
DATA:7
Table 23.6-4 Status Transition of the Data Polling Flag (Status Changes at Abnormal
Operation status
❍ At writing
If a read access is made while the automatic write algorithm is executed, the flash memory
outputs the reverse data of bit7 of the data last written, regardless of the indicated address. If a
read access is made when the automatic write algorithm ends, the flash memory outputs bit7 of
the read value of the indicated address.
❍ At chip or sector deletion
The flash memory outputs "0" while the chip deletion or sector deletion algorithm is executed if a
read access is made from the deleted sector at sector deletion or a read access is made
regardless of the indicated address at chip deletion. Similarly, the flash memory outputs "1" at
the end of the operation.
❍ At temporary stop of sector deletion
The flash memory outputs "1" if a read access is made at temporary stop of sector deletion and
the indicated address specifies the sector being deleted. If the indicated address does not
specify the sector being deleted, the flash memory outputs bit7 (DATA:7) of the read value of
the indicated address. Referencing this bit together with the toggle bit flag (DQ6) enables the
operator to determine whether the sector stops temporarily or which sector is being deleted.
352
Chip or Sector
sector deletion
deletion --> wait
completion --> start
0 --> 1 0
Operation)
DQ7
Temporary
Sector deletion
stop of sector
--> temporary
deletion -->
stop of deletion
restart
Sector being
Sector being
deleted
deleted
0 --> 1 1 --> 0
Writing
DQ7
Temporary
stop of sector
deletion
ongoing
Sector not
being deleted
DATA:7
Chip or sector deletion
0