Sector Erase Timer Flag (Dq3) - Fujitsu F2MC-16LX Hardware Manual

Mb90470 series 16-bit microcontroller
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CHAPTER 26 2M BIT FLASH MEMORY

26.5.4 Sector Erase Timer Flag (DQ3)

The sector erase timer flag (DQ3) indicates whether the device is waiting for the end of
sector erase after starting of the sector erase command.
I State transitions of sector erase timer flag (DQ3)
❍ State changes during normal operation
Write
Operation
operation -->
state
completed
DQ3
0 --> DATA: 3
❍ State changes in operation error mode
Operation
Write
state
operation
DQ3
0
I Sector erase operation
In read accesses after the sector erase command starts, the flash memory outputs "0",
irrespective of the address specified by the address signal for the sector that issued the
command, or it outputs "1" if the sector erase waiting time was exceeded.
If the data polling function or toggle bit function shows that the erase algorithm is being
executed and this flag is set to "1", erasure under internal control will start. Subsequent
commands other than writing the sector erase code or erase suspend are ignored until the
erasure is completed.
If this flag is set to "0", the flash memory will accept writing of the sector erase code. Fujitsu
recommends checking the state of the flag before subsequent sector erase codes are written to
verify the operational state of the device. If a second state check returns "1", the erase code for
an additional sector may not have been accepted.
I Sector erase suspend
If read access is performed when a sector erase operation is suspended, the flash memory
outputs "1" for an address of a sector being erased. Otherwise, the read value of bit 3 (DATA: 3)
for the corresponding address will be output.
482
Chip sector
Sector
erase -->
erase wait
completed
--> start
1
0 --> 1
Chip sector
erase
operation
1
Sector erase
Sector erase -->
suspend -->
erase suspend
resume
(sector being
(sector being
erased)
erased)
1 --> 0
0 --> 1
Sector erased
Suspend mode
Sector not being
erased
DATA: 3

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