Fujitsu 8FX

MB95630H Series
548 FUJITSU SEMICONDUCTOR LIMITED MN702-00009-2v0-E
CHAPTER 26 DUAL OPERATION FLASH MEMORY
26.4 Checking Automatic Algorithm
Execution Status
26.4.5 Toggle Bit2 Flag (DQ2)
The toggle bit2 flag (DQ2) is a hardware sequence flag using the toggle bit
function to indicate whether a read address is an erase target sector in the
sector erase suspend state and whether output data is toggled.
■ Toggle Bit2 Flag (DQ2)
Table 26.4-11 and Table 26.4-12 show the state transition of the toggle bit2 flag during normal
operation and the one during abnormal operation respectively.
● At chip/sector erase
• When read accesses are continuously made to a sector to be erased while 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 continuously made to a sector not to be erased while the automatic
chip/sector erase algorithm is being executed, the Flash memory outputs bit2 (DATA: 2) of
the value read from a read address of each read access.
● At sector erase suspension
• With a sector erase operation suspended, when read accesses are continuously made to a
sector to be erased, the Flash memory toggles the output between "1" and "0" whenever a
read access is made.
• With a sector erase operation suspended, when read accesses are continuously made to a
sector not to be erased, the Flash memory outputs bit2 (DATA: 2) of the read value of a
read address whenever a read access is made.
Table 26.4-11 State Transition of Toggle Bit2 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)
DQ2 0 → DATA: 2 Toggle → 1 Toggle Toggle Toggle DATA: 2
Table 26.4-12 State Transition of Toggle Bit2 Flag (During Abnormal Operation)
Operating state Programming Chip/sector erase
DQ2 0 Toggle