User`s guide

Rev. 1.10 88 November 14, 2014 Rev. 1.10 89 November 14, 2014

HT66FW2230

Wireless Charger A/D Flash 8-Bit MCU

Summary of A/D Conversion Steps

ThefollowingsummarisestheindividualstepsthatshouldbeexecutedinordertoimplementanA/

Dconversionprocess.

• Step1

SelecttherequiredA/DconversionclockbycorrectlyprogrammingbitsADCK2~ADCK0inthe

ADCR1register.

• Step2

EnabletheA/DbyclearingtheADOFFbitintheADCR0registertozero.

• Step3

SelectwhichchannelistobeconnectedtotheinternalA/Dconverterbycorrectlyprogramming

theACS4~ACS0bitswhicharealsocontainedintheADCR0register.

• Step4

SelectwhichpinsaretobeusedasA/Dinputsandcongurethembycorrectlyprogrammingthe

PAS07~PAS00bitsinthePAS0registerandthePAS17~PAS10bitsinthePAS1register.(AN1does

notneedtobeselectedasA/Dinput,becauseitisonlypinwithOCPandthesetwopinsareboth

asinputpins)

• Step5

Iftheinterruptsaretobeused,theinterruptcontrolregistersmustbecorrectlyconfiguredto

ensuretheA/Dconverterinterruptfunctionisactive.Themasterinterruptcontrolbit,EMI,and

theA/Dconverterinterruptbit,ADE,mustbothbesethightodothis.

• Step6

TheanalogtodigitalconversionprocesscannowbeinitialisedbysettingtheSTARTbitin

theADCR0registerfromlowtohighandthenlowagain.Notethatthisbitshouldhavebeen

originallyclearedtozero.

• Step7

Tocheckwhentheanalogtodigitalconversionprocessiscomplete,theEOCBbitintheADCR0

occurstheA/DdataregistersADRLandADRHcanbereadtoobtaintheconversionvalue.Asan

alternativemethod,iftheinterruptsareenabledandthestackisnotfull,theprogramcanwaitfor

anA/Dinterrupttooccur.

Note:Whencheckingfortheendoftheconversionprocess,ifthemethodofpollingtheEOCBbit

intheADCR0registerisused,theinterruptenablestepabovecanbeomitted.

Theaccompanyingdiagramshowsgraphicallythevariousstagesinvolvedinananalogtodigital

conversionprocessanditsassociatedtiming.AfteranA/Dconversionprocesshasbeeninitiated

bytheapplicationprogram,themicrocontrollerinternalhardwarewillbegintocarryoutthe

conversion,duringwhichtimetheprogramcancontinuewithotherfunctions.Thetimetakenforthe

A/Dconversionis16t

ADCK

wheret

ADCK

isequaltotheA/Dclockperiod.