W28V400B Datasheet, PDF (18/48 Pages) Winbond – 4M(512K x 8/256K x 16) SMARTVOLTAGE FLASH MEMORY

W28V400B/T
Start
Write 20H
Block Address
Write D0H,
Block Address
Read Status
Register
SR.7=
0
1
Full Status
Check if Desired
Block Erase
Complete
No
Suspend
Block Erase
Suspend Block
Erase Loop
Yes
Bus Operation
Write
Write
Read
Command
Erase Setup
Erase Confirm
Comments
Data = 20H
Addr = Within Block
to be Erased
Data = D0H
Addr = Within Block
to be Erased
Status Register Data
Standby
Check SR.7
1 = WSM Ready
0 = WSM Busy
Repeat for subsequent block erasures.
Full status check can be done after each block erase or
after a sequence of block erasures.
Write FFH after the last operation to place device in
read array mode.
Full STATUS CHECK PROCEDURE
Read Status Register
Data(See Above)
SR.3=
1
0
1
SR.1=
0
SR.4,5=
1
0
1
SR.5=
0
Block Erase
Sucessfully
Vpp Range Error
Device Protect Error
Command Sequence
Error
Block Erase Error
Bus Operation Command
Standby
Standby
Comments
Check SR.3
1 = V_PP Error Detect
Check SR.1
1 = Device Protect Detect
Standby
Check SR.4, 5
Both 1 = Command
Sequence Error
Standby
Check SR.5
1 = Block Erase Error
SR.5, SR.4, SR.3 and SR.1 are only cleared by the
Clear Status.
Register Command in cases where multiple blocks are
erased before full status is checked.
If error is detected, clear the Status Register before
attempting retry or other error recovery.
Figure 5. Automated Block Erase Flowchart
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