Sector Erase Timer Flag (Dq3) - Fujitsu MB90335 Series Hardware Manual

CHAPTER 22 DUAL OPERATION FLASH MEMORY
22.6 Check the Execution State of Automatic Algorithm
22.6.4

Sector Erase Timer Flag (DQ3)

The sector erase timer flag is used to notify during the period of waiting for sector
erasing after the sector erase command has started.
■ Sector Erase Timer Flag (DQ3)
Table 22.6-9 and Table 22.6-10 give the state transition of the sector erase timer flag.
Table 22.6-9 State Transition of Sector Erase Timer Flag (State Change at Normal Operation)
Programming
→
Operating State
Completed
→
DQ3 0
Table 22.6-10 State Transition of Sector Erase Timer Flag (State Change at Abnormal Operation)
Operating State
DQ3
●
At sector erasing
• If a read access is made after starting the sector erase command and it is within a sector erasing wait
period, the sector erasing timer flag (DQ3) outputs "0". If it exceeds the period, the sector erasing timer
flag (DQ3) outputs "1".
• If the sector erasing timer flag (DQ3) is "1", indicating that the automatic algorithm for sector erasing by
the data polling or toggle bit function is in progress (DQ7 = 0; DQ6 produces a toggle output), sector
erasing is performed. If any command other than the sector erasing suspension is set, it is ignored until
sector erasing is terminated.
• If the sector erasing timer flag (DQ3) is "0", flash memory can accept the sector erase command. To
program the sector erase command, check that the sector erasing timer flag (DQ3) is "0". If the flag is
"1", flash memory may not accept the sector erase command of suspending.
●
At sector erasing suspension
Read access during sector erasing suspension causes flash memory to output "1", if the read address is in
the sector being erased. Flash memory outputs bit3 (DATA: 3) for the read value of the read address when
the read address is not the sector being erased.
500
Chip and Sector
→
Erasing
Completed
DATA:3 1
FUJITSU MICROELECTRONICS LIMITED
Sector Erasing
→
Wait for Sector
Erasing
→
Erasing
Suspended
Started (Sector being
Erased)
→ →
0 1 1
Programming
0
MB90335 Series
Sector Erasing Sector Erasing
→
being
Suspended
Suspended
Resume
(Sector not
(Sector being
being Erased)
Erased)
→
0 0 1
Chip and Sector Erasing
1
CM44-10137-6E
DATA:3