Holtek HT66F0175 - I C Interface

Rev. 1.50 136 August 28, 2017 Rev. 1.50 137 August 28, 2017
HT66F0175/HT66F0185
A/D Flash MCU with EEPROM
HT66F0175/HT66F0185
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.









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2
C Master Slave Bus Connection
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2
C interface Operation
TheI
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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
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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
operateinslavemode,therearetwomethodsoftransferringdataontheI
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Cbus,theslavetransmit
modeandtheslavereceivemode.
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  
  

  

   
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 
 
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  
  
   
  
 
  
    
  



    


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
 
 
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

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
 
 
  
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  

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
I
2
C Block Diagram