MB95630H Series
MN702-00009-1v0-E
FUJITSU SEMICONDUCTOR LIMITED
541
CHAPTER 25 DUAL OPERATION FLASH MEMORY
25.4 Checking Automatic Algorithm
Execution Status
25.4.2
Toggle Bit Flag (DQ6)
The toggle bit flag (DQ6) is a hardware sequence flag using the toggle bit
function to indicate whether the automatic algorithm is being executed or has
terminated.
■
Toggle Bit Flag (DQ6)
Table 25.4-5 and Table 25.4-6 show the state transition of the toggle bit flag during normal
operation and the one during abnormal operation respectively.
●
At programming and chip/sector erase
•
When read accesses are made continuously while the automatic write algorithm or the
automatic chip/sector erase algorithm is being executed, the Flash memory toggles the
output between "1" and "0" at each read access.
•
When read accesses are made continuously after the automatic write algorithm or the chip/
sector erase algorithm terminates, the Flash memory outputs bit6 (DATA:6) of the value
read from the read address at each read access.
●
At sector erase suspension
When a read access is made with a sector erase operation suspended, the Flash memory outputs
"0" if the read address is the sector being erased. Otherwise, the Flash memory outputs bit6
(DATA: 6) of the value read from the read address.
Note:
When using dual-operation Flash memory (Flash memory write control program is
executed on the Flash memory), the toggle bit flag (DQ6) cannot be used to check the
operating state of programming/erasing. See the notes in "25.9 Notes on Using Dual
Operation Flash Memory" when writing a program.
The note above does not apply if the Flash memory write control program is executed on
the RAM.
Table 25.4-5
State Transition of Toggle Bit Flag (During Normal Operation)
Operating
state
Programming
→
Programming
completed
Chip/sector
erase
→
Erasing
completed
Sector erase
wait
→
Erasing started
Sector erase
→
Sector erase
suspended
(Sector being
erased)
Sector erase
suspended
→
Erasing resumed
(Sector being
erased)
Sector erase
being suspended
(Sector not being
erased)
DQ6
Toggle
→
DATA: 6
Toggle
→
1
Toggle
Toggle
→
0
0
→
Toggle
DATA: 6
Table 25.4-6
State Transition of Toggle Bit Flag (During Abnormal Operation)
Operating state
Programming
Chip/sector erase
DQ6
Toggle
Toggle