Instruction(
B1h)
FM25Q64ꢀ
ꢀ
11.2.27ꢀEnterꢀSecuredꢀOTPꢀ(B1h)ꢀ
TheꢀEnterꢀSecuredꢀOTPꢀinstructionꢀisꢀforꢀenteringꢀtheꢀadditionalꢀ4KꢁbitꢀsecuredꢀOTPꢀmode.ꢀTheꢀ
additionalꢀ4KꢁbitꢀsecuredꢀOTPꢀisꢀindependentꢀfromꢀmainꢀarray,ꢀwhichꢀmayꢀbeꢀusedꢀtoꢀstoreꢀuniqueꢀ
serialꢀnumberꢀforꢀsystemꢀidentifier.ꢀAfterꢀenteringꢀtheꢀSecuredꢀOTPꢀmode,ꢀandꢀthenꢀfollowꢀstandardꢀ
readꢀorꢀprogram,ꢀprocedureꢀtoꢀreadꢀoutꢀtheꢀdataꢀorꢀupdateꢀdata.ꢀTheꢀSecuredꢀOTPꢀdataꢀcannotꢀbeꢀ
updatedꢀagainꢀonceꢀitꢀisꢀlockꢁdownꢀ
ꢀ
Pleaseꢀ noteꢀ thatꢀWRSR/WRSCURꢀ commandsꢀ areꢀ notꢀ acceptableꢀ duringꢀ theꢀ accessꢀ ofꢀ secureꢀ
OTPꢀregion,ꢀonceꢀsecurityꢀOTPꢀisꢀlockꢀdown,ꢀonlyꢀcommandsꢀrelatedꢀwithꢀreadꢀareꢀvalid.ꢀ
TheꢀEnterꢀSecuredꢀOTPꢀinstructionꢀsequenceꢀisꢀshownꢀinꢀfigureꢀ27.ꢀ
ꢀ
/CS
Mode
Mode
3
0
0
1
2
3
4
5
6
7
Mode
Mode
3
0
CLK
DI
ꢀ
Figureꢀ27.ꢀEnterꢀSecuredꢀOTPꢀinstructionꢀsequenceꢀ
ꢀ
ꢀ
11.2.28ꢀExitꢀSecuredꢀOTPꢀ(C1h)ꢀ
TheꢀExitꢀSecuredꢀOTPꢀinstructionꢀisꢀforꢀexitingꢀtheꢀadditionalꢀ4KꢁbitꢀsecuredꢀOTPꢀmode.ꢀ
TheꢀExitꢀSecuredꢀOTPꢀinstructionꢀsequenceꢀisꢀshownꢀinꢀfigureꢀ28ꢀ
ꢀ
/CS
Modeꢀ3
Modeꢀ0
0
1
2
3
4
5
6
7
Modeꢀ3
Modeꢀ0
CLK
Instructionꢀ(C1h)
DI
ꢀ
Figureꢀ28.ꢀExitꢀSecuredꢀOTPꢀinstructionꢀsequenceꢀ
ꢀ
ꢀ
preliminary(Aug.18.2010)ꢀ ꢀ ꢀ ꢀ
45ꢀ
FIDELIX [ FIDELIX ]
