Fujitsu MB90390 Series Hardware Manual page 609

Figure 28.7-2 Example of the Flash Memory Sector Erase Procedure
1
Sector erase timer (DQ3)
0
YES
Read internal address
NO
Erase error
Start erasing
FMCS: WE (bit 5)
Enable flash memory erase
Erase command sequence
(1) FxAAAA <-- XXAA
(2) Fx5554 <-- XX55
(3) FxAAAA <-- XX80
(4) FxAAAA <-- XXAA
(5) Fx5554 <-- XX55
(6) Enter code to erase sector
(30H)
Another erase sector
NO
Read internal address 1
Read internal address 2
Toggle bit (DQ6)
data 1(DQ6) = data 2(DQ6)
NO
0
Timing limit (DQ5)
1
Read internal address 1
Read internal address 2
Toggle bit (DQ6)
data 1(DQ6) = data 2(DQ6)
YES
NO
Final sector
YES
FMCS: WE (bit 5)
Disable flash memory erase
Complete erasing
CHAPTER 28 3M-BIT FLASH MEMORY
Next sector
YES
Confirm with the hardware
sequence flags.
581