
3VoltIntel
Advanced+BootBlockFlashMemoryStacked-CSPFamily
20
Datasheet
3.7.5
ReadingaBlock’sLockStatus
Thelockstatusofeveryblockcanbereadintheconfigurationreadmodeofthedevice.Toenter
thismode,write90htothedevice.SubsequentreadsatBlockAddress+00002willoutputthelock
statusofthatblock.Thelockstatusisrepresentedbytheleastsignificantoutputs,DQ
0
andDQ
1
.
DQ
0
indicatestheBlockLock/UnlockstatusandissetbytheLockcommandandclearedbythe
Unlockcommand.ItisalsoautomaticallysetwhenenteringLock-Down.DQ
1
indicatesLock-
DownstatusandissetbytheLock-Downcommand.Itcannotbeclearedbysoftware,onlyby
deviceresetorpower-down.
3.7.6
LockingOperationduringEraseSuspend
Changestoblocklockstatuscanbeperformedduringanerasesuspendbyusingthestandard
lockingcommandsequencestounlock,lock,orlock-downablock.Thisisusefulinthecasewhen
anotherblockneedstobeupdatedwhileaneraseoperationisinprogress.
Tochangeblocklockingduringaneraseoperation,firstwritetheerasesuspendcommand(B0h),
thencheckthestatusregisteruntilitindicatesthattheeraseoperationhasbeensuspended.Next
writethedesiredlockcommandsequencetoablockandthelockstatuswillbechanged.After
completinganydesiredlock,read,orprogramoperations,resumetheeraseoperationwiththe
EraseResumecommand(D0h).
Ifablockislockedorlocked-downduringasuspendederaseofthesameblock,thelockingstatus
bitswillbechangedimmediately,butwhentheeraseisresumed,theeraseoperationwillcomplete.
Lockingoperationscannotbeperformedduringaprogramsuspend.
3.7.7
StatusRegisterErrorChecking
Usingnestedlockingorprogramcommandsequencesduringerasesuspendcanintroduce
ambiguityintostatusregisterresults.
Sincelockingchangesareperformedusingatwocyclecommandsequence,e.g.,60hfollowedby
01htolockablock,followingtheConfigurationSetupcommand(60h)withaninvalidcommand
willproducealockcommanderror(SR.4andSR.5willbesetto1)inthestatusregister.Ifalock
commanderroroccursduringanerasesuspend,SR.4andSR.5willbesetto1,andwillremainat1
aftertheeraseisresumed.Wheneraseiscomplete,anypossibleerrorduringtheerasecannotbe
detectedviathestatusregisterbecauseofthepreviouslockingcommanderror.
Asimilarsituationhappensifanerroroccursduringaprogramoperationerrornestedwithinan
erasesuspend.
Table7. BlockLockStatus
Item
Address
Data
BlockLockConfiguration
BlockIsUnlocked
BlockIsLocked
BlockIsLocked-Down
XX002
LOCK
DQ
0
= 0
DQ
0
= 1
DQ
1
= 1