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3VoltIntel
Advanced+BootBlockFlashMemoryStacked-CSPFamily
Datasheet
19
3.7.1
BlockLockingOperationSummary
Thefollowingconciselysummarizesthelockingfunctionality.
Allblocksarelockedwhenpowered-up,andcanbeunlockedorlockedwiththeUnlockandLock
commands.
TheLock-DowncommandlocksablockandpreventsitfrombeingunlockedwhenWP# = 0.
WhenWP# = 1,Lock-Downisoverriddenandcommandscanunlock/locklocked-down
blocks.
WhenWP#returnsto0,locked-downblocksreturntoLock-Down.
Lock-Downisclearedonlywhenthedeviceisresetorpowered-down.
ThelockingstatusofeachblockcansettoLocked,Unlocked,andLock-Down,eachofwhichwill
bedescribedinthefollowingsections.Acomprehensivestatetableforthelockingfunctionsis
shownin
Table8onpage 21
,andaflowchartforlockingoperationsisshownin
Figure19on
page 50
.
3.7.2
LockedState
Thedefaultstatusofallblocksuponpower-uporresetislocked(states[001]or[101]).Locked
blocksarefullyprotectedfromalteration.Anyprogramoreraseoperationsattemptedonalocked
blockwillreturnanerroronbitSR.1ofthestatusregister.Thestatusofalockedblockcanbe
changedtoUnlockedorLock-Downusingtheappropriatesoftwarecommands.Unlockedblocks
canbelockedissuingthe“Lock”commandsequence,60hfollowedby01h.
3.7.3
UnlockedState
Unlockedblocks(states[000],[100],[110])canbeprogrammedorerased.Allunlockedblocks
returntotheLockedstatewhenthedeviceisresetorpowereddown.Thestatusofanunlocked
blockcanbechangedtoLockedorLocked-Downusingtheappropriatesoftwarecommands.A
LockedblockcanbeunlockedbywritingtheUnlockcommandsequence,60hfollowedbyD0h.
3.7.4
Lock-DownState
BlocksthatareLocked-Down(state[011])areprotectedfromprogramanderaseoperations(just
likeLockedblocks),buttheirprotectionstatuscannotbechangedusingsoftwarecommandsalone.
ALockedorUnlockedblockcanbeLocked-downbywritingtheLock-Downcommandsequence,
60hfollowedby2Fh.Locked-DownblocksreverttotheLockedstatewhenthedeviceisresetor
powereddown.
TheLock-DownfunctionisdependentontheWP#inputball.WhenWP# = 0,blocksinLock-
Down[011]areprotectedfromprogram,erase,andlockstatuschanges.WhenWP# = 1,theLock-
Downfunctionisdisabled([111])andlocked-downblockscanbeindividuallyunlockedby
softwarecommandtothe[110]state,wheretheycanbeerasedandprogrammed.Theseblockscan
thenbere-locked[111]andunlocked[110]asdesiredwhileWP#remainshigh.WhenWP#goes
low,blocksthatwerepreviouslylocked-downreturntotheLock-Downstate[011]regardlessof
anychangesmadewhileWP#washigh.Deviceresetorpower-downresetsallblocks,including
thoseinLock-Down,toLockedstate.