HT45F4M datasheet(38/138 Pages) HOLTEK

38 / 138 page

Rev. 1.10

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Rev. 1.10

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HT45F4M

Lithium Battery Backup Power ASSP MCU

HT45F4M

Lithium Battery Backup Power ASSP MCU

Entering the IDLE0 Mode

ThereisonlyonewayforthedevicetoentertheIDLE0Modeandthatistoexecutethe“HALT”

instructionintheapplicationprogramwiththeIDLENbitinSMODregisterequalto“1”andthe

FSYSONbitinCTRLregisterequalto“0”.Whenthisinstructionisexecutedundertheconditions

describedabove,thefollowingwilloccur:

• Thesystemclockwillbestoppedandtheapplicationprogramwillstopatthe“HALT”instruction,

buttheTimeBaseclockfTBCandthelowfrequencyfSUBwillbeon.

• TheDataMemorycontentsandregisterswillmaintaintheirpresentcondition.

• TheWDTwillbeclearedandresumecounting.

• TheI/Oportswillmaintaintheirpresentconditions.

• Inthestatusregister,thePowerDownflag,PDF,willbesetandtheWatchdogtime-outflag,TO,

willbecleared.

Entering the IDLE1 Mode

ThereisonlyonewayforthedevicetoentertheIDLE1Modeandthatistoexecutethe“HALT”

instructionintheapplicationprogramwiththeIDLENbitinSMODregisterequalto“1”andthe

FSYSONbitinCTRLregisterequalto“1”.Whenthisinstructionisexecutedundertheconditions

describedabove,thefollowingwilloccur:

• ThesystemclocktogetherwiththeTimeBaseclockfTBCandthelowfrequencyfSUBwillbeon

andtheapplicationprogramwillstopatthe“HALT”instruction.

• TheDataMemorycontentsandregisterswillmaintaintheirpresentcondition.

• TheWDTwillbeclearedandresumecounting.

• TheI/Oportswillmaintaintheirpresentconditions.

• Inthestatusregister,thePowerDownflag,PDF,willbesetandtheWatchdogtime-outflag,TO,

willbecleared.

HT45F4M Datasheet(PDF) 38 Page - Holtek Semiconductor Inc