Holtek HT66F30 User Manual

Rev. 2.50 192 June 22, 2017 Rev. 2.50 193 June 22, 2017
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
I
2
C Interface
TheI
2
Cinterfaceisusedtocommunicatewithexternalperipheraldevicessuchassensors,
EEPROMmemoryetc.OriginallydevelopedbyPhilips,itisatwolinelowspeedserialinterface
forsynchronousserialdatatransfer.Theadvantageofonlytwolinesforcommunication,relatively
simplecommunicationprotocolandtheabilitytoaccommodatemultipledevicesonthesamebus
hasmadeitanextremelypopularinterfacetypeformanyapplications.









I
2
C Master Slave Bus Connection
I
2
C Interface Operation
TheI
2
Cserialinterfaceisatwolineinterface,aserialdataline,SDA,andserialclockline,SCL.As
manydevicesmaybeconnectedtogetheronthesamebus,theiroutputsarebothopendraintypes.
Forthisreasonitisnecessarythatexternalpull-highresistorsareconnectedtotheseoutputs.Note
thatnochipselectlineexists,aseachdeviceontheI
2
Cbusisidentiedbyauniqueaddresswhich
willbetransmittedandreceivedontheI
2
Cbus.
WhentwodevicescommunicatewitheachotheronthebidirectionalI
2
Cbus,oneisknownasthe
masterdeviceandoneastheslavedevice.Bothmasterandslavecantransmitandreceivedata,
however,itisthemasterdevicethathasoverallcontrolofthebus.Forthesedevices,whichonly
operatesinslavemode,therearetwomethodsoftransferringdataontheI
2
Cbus,theslavetransmit
modeandtheslavereceivemode.
ThereareseveralcongurationoptionsassociatedwiththeI
2
Cinterface.Oneoftheseistoenable
thefunctionwhichselectstheSIMpinsratherthannormalI/Opins.Notethatiftheconguration
optiondoesnotselecttheSIMfunctionthentheSIMENbitintheSIMC0registerwillhaveno
effect.AconfigurationoptiondeterminesthedebouncetimeoftheI
2
Cinterface.Thisusesthe
systemclocktoineffectaddadebouncetimetotheexternalclocktoreducethepossibilityof
glitchesontheclocklinecausingerroneousoperation.Thedebouncetime,ifselected,canbe
chosentobeeither2or4systemclocks.ToachievetherequiredI
2
Cdatatransferspeed,there
existsarelationshipbetweenthesystemclock,f
SYS
,andtheI
2
Cdebouncetime.ForeithertheI
2
C
StandardorFastmodeoperation,usersmusttakecareoftheselectedsystemclockfrequencyand
thecongureddebouncetimetomatchthecriterionshowninthefollowingtable.
I
2
C Debounce Time Selection I
2
C Standard Mode (100kHz) I
2
C Fast Mode (400kHz)
No debounce f
SYS
> 2MHz f
SYS
> 5MHz
2 system clock debounce f
SYS
> 4MHz f
SYS
> 10MHz
4 system clock debounce f
SYS
> 8MHz f
SYS
> 20MHz
I
2
C Minimum f
SYS
Frequency

Holtek HT66F30 Specifications

General

Brand	Holtek
Model	HT66F30
Category	Computer Hardware
Language	English