Sector Erase Timer Flag (Dq3) - Fujitsu 8FX Hardware Manual

MB95630H Series
26.4.4

Sector Erase Timer Flag (DQ3)

The sector erase timer flag (DQ3) is a hardware sequence flag indicating
whether the Flash memory is waiting for sector erase after the sector erase
command has started.
■ Sector Erase Timer Flag (DQ3)
Table 26.4-9 and Table 26.4-10 show the state transition of the sector erase timer flag during
normal operation and the one during abnormal operation respectively.
Table 26.4-9 State Transition of Sector Erase Timer Flag (During Normal Operation)
Programming
Operating
Programming
state
completed
DQ3 0 DATA: 3
Table 26.4-10 State Transition of Sector Erase Timer Flag (During Abnormal Operation)
Operating state
DQ3
● At sector erase
• When a read access is made after the sector erase command has started, the sector erase
timer flag (DQ3) outputs "0" within the sector erase wait period. The flag outputs "1" if the
sector erase wait period has elapsed.
• When the data polling function or the toggle bit function indicates that the erase algorithm
is being executed (DQ7 = 0, DQ6: toggle output), the Flash memory executes sector erase.
If the command subsequently set is not a sector erase suspend command, it is ignored until
sector erase is terminated.
• If the sector erase timer flag (DQ3) is "0", the Flash memory can accept the sector erase
command. Before writing the sector erase command to the Flash memory, make sure that
the sector erase timer flag (DQ3) is "0". If the flag is "1", the Flash memory may not accept
suspending the sector erase command.
● At sector erase suspension
When a read access is made with the sector erase operation suspended, the Flash memory
outputs "1" if the read address of that read access is the address of a sector being erased. If the
read address is not the address of a sector being erased, the Flash memory outputs bit3
(DATA: 3) of the value read from the read address.
MN702-00009-2v0-E
CHAPTER 26 DUAL OPERATION FLASH MEMORY
Chip/sector
Sector erase
erase
wait
Erasing
Erasing started
completed
1 0 1
Programming
0
FUJITSU SEMICONDUCTOR LIMITED
26.4 Checking Automatic Algorithm
Sector erase Sector erase
Sector erase suspended
suspended Erasing resumed
(Sector being (Sector being
erased) erased)
1
Chip/sector erase
1
Execution Status
Sector erase
being suspended
(Sector not being
erased)
1 DATA: 3
547