HT45F12 datasheet(16/104 Pages) HOLTEK

16 / 104 page

Rev. 0.00

1�

�e�te��e� �� 01�

Rev. 0.00

�e�te��e� �� 01�

HT45F12

8-Bit Flash MCU with Op Amps & Comparators

HT45F12

8-Bit Flash MCU with Op Amps & Comparators

System Architecture

Akeyfactorinthehigh-performancefeaturesoftheHoltekrangeofmicrocontrollersisattributed

totheirinternalsystemarchitecture.Therangeofdevicestakeadvantageoftheusualfeaturesfound

withinRISCmicrocontrollersprovidingincreasedspeedofoperationandenhancedperformance.

Thepipeliningschemeisimplementedinsuchawaythatinstructionfetchingandinstruction

executionareoverlapped,henceinstructionsareeffectivelyexecutedinonecycle,withthe

exceptionofbranchorcallinstructions.An8-bitwideALUisusedinpracticallyallinstructionset

operations,whichcarriesoutarithmeticoperations,logicoperations,rotation,increment,decrement,

branchdecisions,etc.TheinternaldatapathissimplifiedbymovingdatathroughtheAccumulator

andtheALU.CertaininternalregistersareimplementedintheDataMemoryandcanbedirectly

orindirectlyaddressed.Thesimpleaddressingmethodsoftheseregistersalongwithadditional

architecturalfeaturesensurethataminimumofexternalcomponentsisrequiredtoprovidea

functionalI/Owithmaximumreliabilityandflexibility.Thismakesthedevicesuitableforlow-cost,

high-volumeproductionforcontrollerapplications

Clocking and Pipelining

Thesystemclock,derivedfromeitheraCrystal/ResonatororRCoscillatorissubdividedintofour

internallygeneratednon-overlappingclocks,T1~T4.TheProgramCounterisincrementedatthe

beginningoftheT1clockduringwhichtimeanewinstructionisfetched.TheremainingT2~T4

clockscarryoutthedecodingandexecutionfunctions.Inthisway,oneT1~T4clockcycleforms

oneinstructioncycle.Althoughthefetchingandexecutionofinstructionstakesplaceinconsecutive

instructioncycles,thepipeliningstructureofthemicrocontrollerensuresthatinstructionsare

effectivelyexecutedinoneinstructioncycle.Theexceptiontothisareinstructionswherethe

contentsoftheProgramCounterarechanged,suchassubroutinecallsorjumps,inwhichcasethe

instructionwilltakeonemoreinstructioncycletoexecute.

Forinstructionsinvolvingbranches,suchasjumporcallinstructions,twoinstructioncyclesare

requiredtocompleteinstructionexecution.Anextracycleisrequiredastheprogramtakesone

cycletofirstobtaintheactualjumporcalladdressandthenanothercycletoactuallyexecutethe

branch.Therequirementforthisextracycleshouldbetakenintoaccountbyprogrammersintiming

sensitiveapplications.

Fe tc h In st . ( PC )

Ex ec ut e In st . (P C- 1)

Fe tc h In st . (P C+ 1)

Ex ec ut e In st . (P C)

Fe tc h In st . (P C+ 2)

Ex ec ut e In st . (P C+ 1)

PC +1

PC +2

O sci ll at or C lo ck

(S yst em C lo ck)

P has e Cl o ck T 1

Pr og ra m C oun te r

P has e Cl o ck T 2

P has e Cl o ck T 3

P has e Cl o ck T 4

Pi pe lin in g

System Clocking and Pipelining

HT45F12 Datasheet(PDF) 16 Page - Holtek Semiconductor Inc

HT45F12 Datasheet(HTML) 16 Page - Holtek Semiconductor Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL