FM25Q64ꢀ
ꢀ
11.2.22ꢀPowerꢁdownꢀ(B9h)ꢀ
Althoughꢀ theꢀ standbyꢀ currentꢀ duringꢀ normalꢀ operationꢀ isꢀ relativelyꢀ low,ꢀ standbyꢀ currentꢀ canꢀ beꢀ
furtherꢀreducedꢀwithꢀtheꢀPowerꢁdownꢀinstruction.ꢀTheꢀlowerꢀpowerꢀconsumptionꢀmakesꢀtheꢀPowerꢁ
downꢀ instructionꢀ especiallyꢀ usefulꢀ forꢀ batteryꢀ poweredꢀ applicationsꢀ (Seeꢀ ICC1ꢀ andꢀ ICC2ꢀ inꢀ ACꢀ
Characteristics).ꢀTheꢀinstructionꢀisꢀinitiatedꢀbyꢀdrivingꢀtheꢀ/CSꢀpinꢀlowꢀandꢀshiftingꢀtheꢀinstructionꢀ
codeꢀ“B9h”ꢀasꢀshownꢀinꢀfigureꢀ22.ꢀ
ꢀ
Theꢀ/CSꢀpinꢀmustꢀbeꢀdrivenꢀhighꢀafterꢀtheꢀeighthꢀbitꢀhasꢀbeenꢀlatched,ꢀIfꢀthisꢀisꢀnotꢀdoneꢀtheꢀPowerꢁ
downꢀ instructionꢀ willꢀ notꢀ beꢀ executed.ꢀ Afterꢀ /CSꢀ isꢀ drivenꢀ high,ꢀ theꢀ Powerꢁdownꢀ stateꢀ willꢀ beꢀ
enteredꢀwithinꢀtheꢀtimeꢀdurationꢀofꢀtDPꢀ(SeeꢀACꢀCharacteristics).ꢀWhileꢀinꢀtheꢀReleaseꢀpowerꢁdownꢀ
/DeviceꢀIDꢀinstruction,ꢀwhichꢀrestoresꢀtheꢀdeviceꢀtoꢀnormalꢀoperation,ꢀwillꢀbeꢀrecognized.ꢀAllꢀotherꢀ
instructionsꢀ areꢀ ignored.ꢀ Thisꢀ includesꢀ theꢀ Readꢀ Statusꢀ Registerꢀ instruction,ꢀ whichꢀ isꢀ alwaysꢀ
availableꢀduringꢀnormalꢀoperation.ꢀIgnoringꢀallꢀbutꢀoneꢀinstructionꢀmakesꢀtheꢀPowerꢀDownꢀstateꢀaꢀ
usefulꢀ conditionꢀ forꢀ securingꢀ maximumꢀ writeꢀ protection.ꢀ Theꢀ deviceꢀ alwaysꢀ powersꢁupꢀ inꢀ theꢀ
normalꢀoperationꢀwithꢀtheꢀstandbyꢀcurrentꢀofꢀICC1.ꢀ
ꢀ
ꢀ
Figureꢀ22.ꢀDeepꢀPwerꢁdownꢀInstructionꢀSequenceꢀDiagramꢀ
ꢀ
ꢀ
ꢀ
ꢀ
11.2.23ꢀReleaseꢀPowerꢁdownꢀ/ꢀDeviceꢀIDꢀ(ABh)ꢀ ꢀ
TheꢀReleaseꢀfromꢀPowerꢁdownꢀ/ꢀDeviceꢀIDꢀinstructionꢀisꢀaꢀmultiꢁpurposeꢀinstruction.ꢀItꢀcanꢀbeꢀusedꢀ
toꢀreleaseꢀtheꢀdeviceꢀfromꢀtheꢀpowerꢁdownꢀstateꢀorꢀobtainꢀtheꢀdeviceꢀelectronicꢀidentificationꢀ(ID)ꢀ
number.ꢀ
ꢀ
Toꢀreleaseꢀtheꢀdeviceꢀfromꢀtheꢀpowerꢁdownꢀstate,ꢀtheꢀinstructionꢀisꢀissuedꢀbyꢀdrivingꢀtheꢀ/CSꢀpinꢀ
low,ꢀshiftingꢀtheꢀinstructionꢀcodeꢀ“ABh”ꢀandꢀdrivingꢀ/CSꢀhighꢀasꢀshownꢀinꢀfigureꢀ23a.ꢀReleaseꢀfromꢀ
powerꢁdownꢀwillꢀtakeꢀtheꢀtimeꢀdurationꢀofꢀtRES1ꢀ(SeeꢀACꢀCharacteristics)ꢀbeforeꢀtheꢀdeviceꢀwillꢀ
resumeꢀ normalꢀ operationꢀ andꢀ otherꢀ instructionsꢀ areꢀ accepted.ꢀ Theꢀ /CSꢀ pinꢀ mustꢀ remainꢀ highꢀ
duringꢀtheꢀtRES1ꢀtimeꢀduration.ꢀ
WhenꢀusedꢀonlyꢀtoꢀobtainꢀtheꢀDeviceꢀIDꢀwhileꢀnotꢀinꢀtheꢀpowerꢁdownꢀstate,ꢀinstructionꢀisꢀinitiatedꢀ
byꢀdrivingꢀtheꢀ/CSꢀpinꢀlowꢀandꢀshiftingꢀtheꢀinstructionꢀcodeꢀ“ABh”ꢀfollowedꢀbyꢀ3ꢁdummyꢀbytes.ꢀTheꢀ
DeviceꢀIDꢀbitsꢀareꢀthenꢀshiftedꢀonꢀtheꢀfallingꢀedgeꢀofꢀCLKꢀwithꢀmostꢀsignificantꢀbitꢀ(MSB)ꢀfirstꢀasꢀ
shownꢀinꢀfigureꢀ23b.ꢀTheꢀDeviceꢀIDꢀvalueꢀforꢀtheꢀFM25Q32ꢀisꢀlistedꢀinꢀManufacturerꢀandꢀDeviceꢀ
Identificationꢀ table.ꢀ Theꢀ Deviceꢀ IDꢀ canꢀ beꢀ readꢀ continuously.ꢀ Theꢀ instructionꢀ isꢀ completedꢀ byꢀ
drivingꢀ/CSꢀhigh.ꢀ
Whenꢀ usedꢀ ꢀ toꢀ releaseꢀ theꢀ deviceꢀ fromꢀ theꢀ powerꢁdownꢀ stateꢀ andꢀ obtainꢀ theꢀ Deviceꢀ ID,ꢀ theꢀ
preliminary(Aug.18.2010)ꢀ ꢀ ꢀ ꢀ
38ꢀ
FIDELIX [ FIDELIX ]
