Fujitsu 8FX User Manual

MB95630H Series
546 FUJITSU SEMICONDUCTOR LIMITED MN702-00009-2v0-E
CHAPTER 26 DUAL OPERATION FLASH MEMORY
26.4 Checking Automatic Algorithm
Execution Status
26.4.3 Execution Timeout Flag (DQ5)
The execution timeout flag (DQ5) is a hardware sequence flag indicating that
the execution time of the automatic algorithm exceeds a specified time
(required for programming/erasing) in the Flash memory.
■ Execution Timeout Flag (DQ5)
Table 26.4-7 and Table 26.4-8 show the state transition of the execution timeout flag during
normal operation and the one during abnormal operation respectively.
● At programming and chip/sector erase
When a read access is made with the automatic write algorithm or the automatic chip/sector
erase algorithm invoked, the flag outputs "0" when the algorithm execution time is within the
specified time (required for programming/erasing) or "1" when it exceeds that time.
The execution time-out flag (DQ5) can be used to check whether programming/erasing has
succeeded or failed regardless of whether the automatic algorithm has been running or
terminated. When the execution timeout flag (DQ5) outputs "1", it can be judged that
programming fails if flash memory program/erase status bit (RDY) in the flash memory status
register (FSR) is "0".
If an attempt is made to write "1" to a Flash memory address holding "0", for example, the
Flash memory is locked, the time limit is exceeded and the execution time-out flag (DQ5)
outputs "1". The state in which the execution time-out flag (DQ5) outputs "1" means that the
Flash memory has not been used correctly; it does not mean that the Flash memory is
defective. When this state occurs, execute the reset command.
Table 26.4-7 State Transition of Execution Timeout 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)
DQ5 0 → DATA: 5 0 → 1 0 0 0 DATA: 5
Table 26.4-8 State Transition of Execution Timeout Flag (During Abnormal Operation)
Operating state Programming Chip/sector erase
DQ5 1 1

Fujitsu 8FX Specifications

General

Brand	Fujitsu
Model	8FX
Category	Computer Hardware
Language	English